E1566 V4 - World Bank Documents & Reports

ESIA o f the Kaliti Wastewater Treatment Plant and Sewer Lines Expansion and Rehabilitation Project 2013

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Consultants: Beles Engineering PLC

ENVIRONMENTAL AND SOCIAL IMPACT ASSESSMENT OF THE WASTEWATER

TREATMENT PLANT AND SEWER LINES EXPANSION AND REHABILITATION IN

THE KALITI CATCHMENT

(Final Report)\

(Volume I)

Client:

Addis Ababa Water and Sewerage Authority (AAWSA)

Water, Sanitation Rehabilitation and Development Project Office

Consultant:

Beles Engineering P.L.C

(Experts in Water, Land & Environment)

October 2014

Addis Ababa, Ethiopia

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ESIA of the Kaliti Wastewater Treatment Plant and Sewer Lines Expansion and Rehabilitation Project 2014

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TABLE OF CONTENTS

TABLE OF CONTENTS .................................................................................................................................................. II

LIST OF TABLES ............................................................................................................................................................ VI

LIST OF FIGURES ....................................................................................................................................................... VIII

ACKNOWLEDGEMENTS ............................................................................................................................................. IX

ACRONYMS ...................................................................................................................................................................... X

EXECUTIVE SUMMARY ............................................................................................................................................ XII

1. INTRODUCTION ...................................................................................................................................................... 1

1.1 BACKGROUND ....................................................................................................................................................... 1

1.2 OBJECTIVE OF ESIA STUDY ................................................................................................................................... 2

1.2.1 General Objective ......................................................................................................................................... 2

1.2.2 Specific Objectives ........................................................................................................................................ 2

1.3 SCOPE OF THE STUDY ............................................................................................................................................ 2

1.4 METHODOLOGY ..................................................................................................................................................... 2

1.4.1 Scoping Method ............................................................................................................................................ 2

1.4.2 Baseline Investigation Methods .................................................................................................................... 3

1.4.3 Environmental and Socio-economic Impact Assessment Methodology ........................................................ 4

2 POLICY, LEGISLATION AND ADMINISTRATIVE FRAMEWORK .............................................................. 7

2.1 INSTITUTIONAL ARRANGEMENTS .......................................................................................................................... 7

2.1.1 National Environmental Protection Authority .............................................................................................. 7

2.1.2 Regional Environmental Agencies ................................................................................................................ 7

2.1.3 Sectoral Environmental Units ....................................................................................................................... 8

2.2 NATIONAL POLICY AND STRATEGIES ..................................................................................................................... 8

2.2.1 The Constitution of the Federal Democratic Republic of Ethiopia (Proc. No.1 /1995) ................................ 8

2.2.2 Conservation Strategy of Ethiopia (1997) .................................................................................................... 9

2.2.3 Environmental Policy of the Federal Democratic Republic of Ethiopia (1997) ........................................... 9

2.2.4 National Policy on Biodiversity Conservation and Research (1998) ........................................................... 9

2.2.5 Sectoral Policies ......................................................................................................................................... 10

2.3 RELEVANT ENVIRONMENTAL LEGISLATIONS AND REGULATIONS ....................................................................... 11

2.3.1 Proclamation for the Establishment of Environmental Protection Organs No. 295/2002 .......................... 11

2.3.2 Proclamation on Environmental Impact Assessment No. 299/2002 ........................................................... 11

2.3.3 Proclamation on Environmental Pollution Control No. 300/2002 ............................................................. 12

2.3.4 Industrial Pollution Regulation No. 159 /2008 ........................................................................................... 12

2.4 INSTITUTIONAL AND ADMINISTRATIVE FRAMEWORK .......................................................................................... 12

2.4.1 Administrative Framework ......................................................................................................................... 12

2.5 WORLD BANK SAFEGUARD POLICIES .................................................................................................................. 14

2.6 ESMF AND RPF REQUIREMENTS ........................................................................................................................ 15

2.6.1 ESMF Requirements ................................................................................................................................... 15

2.6.2 RPF Requirements ...................................................................................................................................... 15

3 PROJECT DESCRIPTION ..................................................................................................................................... 17

3.1 INTRODUCTION .................................................................................................................................................... 17


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3.2 COMPONENTS OF THE PROJECT ............................................................................................................................ 18

3.2.1 The Sewer Lines .......................................................................................................................................... 18

3.2.2 Existing Wastewater Treatment Plant ......................................................................................................... 24

3.2.3 Proposed Technology for the New WTP ..................................................................................................... 28

3.3 DOWNSTREAM AREAS FROM THE TREATMENT PLANT ........................................................................................ 48

3.3.1 Farming Areas ............................................................................................................................................ 48

3.3.2 Settlement Area ........................................................................................................................................... 48

3.3.3 Riparian Vegetation .................................................................................................................................... 48

4 ENVIRONMENT AND SOCIAL BASELINE CONDITIONS ............................................................................ 50

4.1 THE PHYSICAL ENVIRONMENT ............................................................................................................................ 50

4.1.1 Topography and Drainage .......................................................................................................................... 50

4.1.2 Land use / land cover .................................................................................................................................. 51

4.1.3 Climate ........................................................................................................................................................ 54

4.1.4 Hydrology ................................................................................................................................................... 56

4.1.5 Geology ....................................................................................................................................................... 56

4.1.6 Water Resource and Quality ....................................................................................................................... 62

4.1.7 Wastewater Quality ..................................................................................................................................... 63

4.2 THE BIOLOGICAL ENVIRONMENT BASELINE CONDITIONS ................................................................................... 64

4.2.1 Vegetation and Flora .................................................................................................................................. 64

4.2.2 Plantation Forest ........................................................................................................................................ 64

4.2.3 Vegetables and Plants ................................................................................................................................. 64

4.2.4 Birds and Wildlife ....................................................................................................................................... 64

4.3 SOCIOECONOMIC ENVIRONMENT OF ADDIS ABABA ............................................................................................ 65

4.3.1 Institutional and Administrative Context of Addis Ababa ........................................................................... 65

4.3.2 Demographic Structure ............................................................................................................................... 67

4.3.3 Housing Conditions .................................................................................................................................... 68

4.3.4 Major economic Activities .......................................................................................................................... 69

4.3.5 Land use Pattern ......................................................................................................................................... 70

4.3.6 Educational Facilities ................................................................................................................................. 70

4.3.7 Health Facilities.......................................................................................................................................... 71

4.3.8 Road Facilities ............................................................................................................................................ 71

4.3.9 Telecommunication Facilities ..................................................................................................................... 72

4.3.10 Water Supply ............................................................................................................................................... 72

4.3.11 Sanitation Facilities .................................................................................................................................... 72

4.4 GENDER ISSUE ..................................................................................................................................................... 72

4.5 PROJECT AFFECTED PERSONS .............................................................................................................................. 73

4.5.1 Fully Affected Persons ................................................................................................................................ 73

4.5.2 Partially Affected Persons and Organizations ............................................................................................ 73

5 ANALYSIS OF PROJECT SPECIFIC ALTERNATIVES .................................................................................. 75

5.1 PROJECT ALTERNATIVES ..................................................................................................................................... 75

5.2 NO ACTION/ WITHOUT PROJECT ALTERNATIVE .................................................................................................. 75

5.3 AS PROPOSED ALTERNATIVE ............................................................................................................................... 76

5.4 ALTERNATIVE DESIGN OPTIONS .......................................................................................................................... 76

5.4.1 Sewer trunk Lines ........................................................................................................................................ 76


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5.5 TREATMENT AND DISPOSAL ALTERNATIVES ........................................................................................................ 78

5.5.1 Comparison of the commonly used wastewater treatment systems ............................................................. 79

6 ENVIRONMENTAL AND SOCIAL IMPACTS IDENTIFICATION, ANALYSIS AND MITIGATION

MEASURES ...................................................................................................................................................................... 82

6.1 CHECKLIST OF POTENTIAL ENVIRONMENTAL AND SOCIAL IMPACTS ................................................................... 82

6.2 ENVIRONMENTAL AND SOCIAL IMPACTS ........................................................................................................... 102

6.2.1 Impacts in Sewer trunk Line Part of the Project ....................................................................................... 102

6.2.2 Impacts in the Wastewater Treatment Plant ............................................................................................. 107

6.2.3 Impacts Downstream of the WTP .............................................................................................................. 115

6.3 MITIGATION MEASURES .................................................................................................................................... 121

6.3.1 Mitigation Measures in the Sewer trunks Line Part ................................................................................. 121

6.3.2 Mitigation Measures for the Impacts of the Wastewater Plant ................................................................. 124

6.3.3 Mitigation Measures for the Impacts Downstream of the Wastewater Plant ............................................ 127

6.1.1 Concluding Remarks ................................................................................................................................. 127

7 STAKEHOLDERS ANALYSIS ............................................................................................................................ 128

7.1 GENERAL ........................................................................................................................................................... 128

7.2 SCOPE OF THE SOCIOECONOMIC STUDY ............................................................................................................. 128

7.3 APPROACH AND METHODOLOGY ....................................................................................................................... 128

7.4 THE MAIN STAKEHOLDERS IN THE PROJECT AREA AND THE CONSULTATION PROCESS .................................... 129

7.4.1 Consultation with sub city administrations ............................................................................................... 129

7.4.2 Consultations with the Project Affected Persons ...................................................................................... 130

7.5 TYPE OF STAKEHOLDERS ................................................................................................................................... 130

7.5.1 Internal stakeholders ....................................................................................................................................... 130

7.5.2 External Stakeholders ...................................................................................................................................... 131

7.6 ROLES OF MAIN STAKEHOLDERS AND STAKEHOLDER ANALYSIS ...................................................................... 131

7.6.1 Internal Stakeholders ....................................................................................................................................... 131

7.6.2 External Stakeholders ...................................................................................................................................... 132

7.7 STAKEHOLDER ANALYSIS SUMMARY ................................................................................................................ 132

7.8 CONCLUDING REMARK ...................................................................................................................................... 133

8 ENVIRONMENTAL AND SOCIAL MANAGEMENT AND MONITORING PLANS ................................. 134

8.1 ENVIRONMENTAL AND SOCIAL MANAGEMENT PLANS ...................................................................................... 134

8.2 ENVIRONMENTAL AND SOCIAL MONITORING PLAN .......................................................................................... 146

8.3 IMPLEMENTATION ARRANGEMENT OF THE EMMP ............................................................................................ 153

8.4 TRAINING ON ENVIRONMENTAL ASPECTS ......................................................................................................... 154

8.5 ENVIRONMENTAL MANAGEMENT BUDGET ........................................................................................................ 154

9 SUMMARY OF THE COST ESTIMATES FOR THE PROPOSED MITIGATION MEASURES .............. 158

10 CONCLUSIONS AND RECOMMENDATIONS ............................................................................................ 160

10.1 CONCLUSIONS ........................................................................................................................................................ 160

10.2 RECOMMENDATIONS .............................................................................................................................................. 162

SELECTED REFERENCES ......................................................................................................................................... 163

ANNEXES ....................................................................................................................................................................... 165


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ANNEX 1 LIST OF PROJECT AFFECTED PEOPLE AND PROPERTY ..................................................................................... 165

ANNEX 2. PROFESSIONALS INVOLVED IN THE STUDY .................................................................................................... 181

ANNEX 3 HISTORICAL WATER QUALITY RECORDS IN THE PROJECT AREA ...................................................................... 182

ANNEX 4: FAO GUIDELINE FOR WASTEWATER USE IN AGRICULTURE ......................................................................... 184

ANNEX 5: USEPA, NPDES AND EC EDR FOR DISCHARGES FROM WASTEWATER TREATMENT PLANTS ................... 187

ANNEX 6 ENVIRONMENT, HEALTH AND SAFETY ASPECTS OF THE PROJECT .................................................................. 188

ANNEX 7. FORMAT FOR ASSET SURVEY ALONG THE SEWER LINES ................................................................................. 196


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List of Tables

Table 1.1: Physical Environmental Receptors ...................................................................................................................... 4

Table 1.2: Biological Environmental Receptors ................................................................................................................... 4

Table 1.3: Socio-Economic Environmental Receptors ......................................................................................................... 4

Table 1.4: Criteria Used in the Evaluation of Impacts .......................................................................................................... 5

Table 3.1: Proposed Sewer Trunk and Manhole Diameters ............................................................................................... 21

Table 3.2: Summary of Proposed Sewer Trunks For Kaliti Catchment. ............................................................................. 21

Table 3.3: Characteristics of the Biological Wastewater Treatment Plant .......................................................................... 28

Table 3.4: Wastewater Characteristics for Detailed Design ............................................................................................... 30

Table 3.5: Treated Effluent Characteristics for Design ...................................................................................................... 30

Table 3.6: Trickling Filter Size ........................................................................................................................................... 39

Table 3.7 Common Anaerobic Digesters ............................................................................................................................ 42

Table 3.8 Types of Sludge Drying Beds and Lagoons........................................................................................................ 44

Table 4.1: Summary of Mean Monthly Long-Term Meteorological Data of Addis Ababa Area. ...................................... 55

Table 4.2: Basic Statistical Description For Historical Raw Wastewater At The Kaliti Wtp. ............................................ 63

Table 4.3: Water Quality Analysis Results Of The Project Area ....................................................................................... 63

Table:4.4 Basic Demographic Data of Addis Ababa .......................................................................................................... 67

Table 4.5: Demographic Indicators of Addis Ababa, ......................................................................................................... 68

Table 4.6 Housing Types in the Three Affected Sub-Cities ............................................................................................... 69

Table: 4.7 Housing Conditions and Number of Houses of PAPs ....................................................................................... 69

Table 4.8: Sectoral Distribution of Urban Employment ..................................................................................................... 69

Table 4.9: Economically Active Persons 10 Years and Above........................................................................................... 70

Table 4.10: Status of Education .......................................................................................................................................... 71

Table 4.11Health facilities in the City Administration of Addis Ababa ............................................................................. 71

Table 4.12 Number of health service providers .................................................................................................................. 72

Table 4.13 Road Facilities of the City ................................................................................................................................ 72

Table 5.1: Selection Matrix Results .................................................................................................................................... 79

Table 5.2: Construction Cost Estimates for Top Three Options ......................................................................................... 79

Table 5.3 Comparison of The Commonly Used Wastewater Treatment Systems .............................................................. 81

Table 6.1 Check List of Potential Environmental Impacts in the Sewer Trunk Line Part .................................................. 83

Table 6.2 List Of Properties that iill be Affected/Damaged During the Mobilization Phase .............................................. 85

Table 6.3 Check List of Potential Environmental Impacts in the Wastewater Treatment Plant ......................................... 85

Table 6.4 Check list of Potential Environmental Impacts Downstream of the Wastewater treatment plant ....................... 87

Table 6.5 Summary of Important Negative Impacts ......................................................................................................... 119


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Table 6.6 Summary of Important Positive Impacts .......................................................................................................... 120

Table 7.1: Opinion of the Would Be Affected Households About the Project Along The Trunk Lines.. ......................... 132

Table 7.2: Opinion of the Would Be Affected Households About theProject Around and Downstream of the WTP ..... 132

Table 8.1Environmental and Social Management Plan for the Sewer Trunk Line Part of the Project ............................. 136

Table 8.2Environmental and Social Management Plan for the Wastewater Treatment Plant .......................................... 139

Table 8.3Environmentala Social Management Plan for the Area Downstream of The WTP ........................................... 145

Table 8.4Environmental and Social Monitoring Plan ....................................................................................................... 147

Table 8.5 Summary of The Budget for Environmental Management ............................................................................... 154

Table 9.1: Estimated Cost for Compensation ................................................................................................................... 158

Table 9.2: Estimated Administration Cost of RAP Implementation For District 7 .......................................................... 159


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List of Figures

Figure 2.1: Administrative Sub Division of Addis Ababa City .......................................................................................... 13

Figure 3.1 Plates Showing Grave Situations of Liquid Waste Management in the Project Area ....................................... 18

Figure 3.2: Spot Image Showing the Western Trunk .......................................................................................................... 20

Figure 3.3: Spot Image Showing the Eastern Trunk ........................................................................................................... 22

Figure 3.4: Spot Image Showing the Southern Trunk ......................................................................................................... 23

Figure 3.5: Location Map of the Proposed Trunk Lines and Existing Sewer Lines ........................................................... 24

Figure 3.6: Spot Image of the Kaliti WTP .......................................................................................................................... 25

Figure 3.7: Plates Showing Some Features of the Kaliti WTP ........................................................................................... 26

Figure 3.8: Kaliti Wtp Flow Diagram. ................................................................................................................................ 27

Figure 3.9: Draft Lay out of the Treatment Plant................................................................................................................ 31

Figure 3.10: the Proposed Wastewater Treatment System ................................................................................................. 32

Figure 3.11: Some Features of Downstream Areas from the Treatment Plant ................................................................... 49

Figure 4.1: Digital Elevation Model and Simplified Drainage Map of the Akaki River Basin with City Boundary .......... 50

Figure 4.2: Drainage Map Showing the Little Akaki and Big Akaki Rivercatchments With Project Area ........................ 51

Figure 4.3: Simplified Digital Elevation Model With N-S Sections of the Akaki River Basin .......................................... 52

Figure 4.4: Simplified Land Use/Cover Map of Addis Ababa Area ................................................................................... 53

Figure 4.5: Typical Vegetated Land Cover Types in the Project Area ............................................................................... 53

Figure 4.6: The Two Sensitive Areas That Are Going To Be Affected Bythe Sewer Lines............................................... 54

Figure 4.7: Hydrograph of Big Akaki and Little Akaki Rivers ......................................................................................... 56

Figure 4.8: Simplified Geological Map of the Study Area ................................................................................................. 58

Figure 4.9: Typical Fractured Permeable Volcanic Rocks Along the Eastern Proposed Sewer Line. ................................ 60

Figure 4.10: Simplified Soil Map of Addis Ababa Area .................................................................................................... 61

Figure 4.11: Photographs Showing Some of the Biological Elements O the Project Area. ............................................... 65

Figure 4.12: Map of Addis Ababa City Showing the Division by Sub-Cities and District................................................. 66

Figure 4.13: Growth Trend of Addis Ababa Between 1975 and 2000................................................................................ 67

Figure 4.15: Some Field Activities Related to Socioeconomic Surveying, Asset Enumeration and Project Area

Observations. ...................................................................................................................................................................... 74

Figure 8.1 Proposed Organization Chart for the Implementation of the Emmp ............................................................... 153


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ACKNOWLEDGEMENTS

We are highly indebted to the Addis Ababa Water and Sewerage Authority (AAWSA), Water,

Sanitation Rehabilitation and Development Project Office for providing valuable documents for the

project and facilitating the field visits. Many experts in the AAWSA project office cooperated and

provided available information for the working team. Our appreciation extends to AAWSA

laboratory for analyzing water samples on time. In this regard, our particular appreciation goes to

AtoZelekeTeferi. In general, the client’s cooperation is extremely appreciable. We are also indebted

to all Sub city and District administration officials in the project area for organizing meetings and

focus group discussions and the experts from the various sectoral offices in the Addis Ababa city

administration for providing valuable information. The Addis Ababa Roads Authority, Engineering

Design Division provided valuable information on current costs for the assets that will be affected by

the project. We are also thankful to the community which also participated in meetings and provided

valuable verbal information indicated in the RAP and socioeconomic report. All who provided verbal

and written information for this report are highly appreciated.


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ACRONYMS

AAEPA Addis Ababa city administration Environmental Protection Authority ADLI Agricultural Development-Led Industrialization AAHB Addis Ababa city administration Health Bureau AALSAB Addis Ababa city administration Labor and Social Affairs Bureau AAWSA Addis Ababa Water and Sewerage Authority ACC Awareness Creation Committee BOD Biochemical Oxygen Demand BOD5 5 day Biochemical Oxygen Demand BoLAEP Bureau of Land Administration and Environmental Protection CIS Corrugated Iron Sheet COD Chemical Oxygen Demand CSA Central Statistics Agency CSE Conservation Strategy of Ethiopia CW Constructed Wetland DEM Digital Elevation Model EBCS Ethiopian Building Code Standard EEPCo Ethiopian Electric Power Corporation EIA Environmental Impact Assessment EISs Environmental Impact Statements EMP Environmental Management Plan EMMP Environmental Management and Monitoring Plan EMU Environmental Management Unit EPA Environmental Protection Authority EPE Environmental Policy of Ethiopia ESMF Environmental and Social Management Framework ESIA Environmental and Social Impact Assessment ESMP Environmental and Social Management Plan ETB Ethiopian Birr EWRMP Ethiopian Water Resource Management Policy

FAO Food and Agriculture Organization FDRE Federal Democratic Republic of Ethiopia FOG Fats, Oil and Grease FWS Free Water Surface Gm/m

2 Gram per meter square

HH Households HRT Hydraulic Retention Time IBA Important Bird Area .- ITCZ Inter Tropical Convergence Zone MBBR Moving Bed BioReactor MoARD Ministry of Agriculture and Rural Development MoEF Ministry of Environment and Forestry MoH Ministry of Health MoM Ministry of Mines MoTI Ministry of Transport and Infrastructure MoTC Ministry of Tourism and Culture MoWE Ministry of Water and Energy MoWUD Ministry of Works and Urban Development NRS National Regional State


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OLR Organic Loading Rate O&M Operation and Maintenance PAPs Project Affected Persons PIM Project Implementation Manual PSC Project Steering Committee PVC Poly Vinyl Chloride RAP Resettlement Action Plan

RTD Residence Time Distribution RPF Resettlement Policy Framework REAs Regional Environmental Authorities SPM Suspended Particulate Matter STD Sexually Transmitted Diseases

TDS Total Dissolved Solids

TF Trickling Filter TSS Total Suspended Solids UASB Up-flow Anaerobic Sludge Blanket UNECA United Nations Economic Commission for Africa WHO World Health Organization WTP Wastewater Treatment Plant


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EXECUTIVE SUMMARY

I. Introduction

The project focuses on the environmental and social impact assessment (ESIA) on the Kaliti

wastewater and sewer line expansion project. Spatially three important components exist. These

are the treatment system, the new sewer lines and the immediate areas downstream of the

treatment plant. The ESIA study has focused on the study of the impacts of the project on the

biological, physical and social environments and their mitigation measures.

Background

The population of Addis Ababa City and provision of water supply and other socio economic

developmental activities are increasing from time to time. In line with this, the amount of

domestic and industrial wastewater is also increasing. The Kaliti wastewater treatment plant

which was designed for a maximum capacity of 7,500m3/d of wastewater is currently operating

beyond its design limit. However, it is not in a position to satisfy the needs of the city. As a

result, sewage waste overflows on to streets and into the water courses. Septic pump-out trucks

do not access all areas to service the new high volume customers. Sewage from septic tanks and

latrines continue to pollute groundwater. There are uncontrolled and open wastewater disposal,

illegal connections of sewerage to storm drainage lines and to nearby rivers. The situation is

affecting public health and aesthetics of the city.

In order to alleviate this big problem, Addis Ababa Water and Sewerage Authority (AAWSA)

has embarked for study and design of wastewater collection, treatment and disposal systems in

the Kaliti catchment area.

Following the design and rehabilitation of the existing wastewater facility, AAWSA invited

consultants to bid for environmental and social impact assessment of the Kaliti wastewater

treatment and sewer line rehabilitation and expansion project. Beles Engineering PLC has won

the bid and started the ESIA study of the project.

Accordingly two documents, ESIA (Volume I) and RAP (Volume II) are prepared.

Objective of the Study

The general objective of the study is to conduct detailed environmental and social impact

assessment of the wastewater treatment expansion and sewerage line within the Kaliti catchment

area. The present report is based on Terms of Reference (TOR) provided to the consultants as

part of their contract document. The report is prepared taking into account the guidelines of the


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FDRE Environmental Protection Authority and the World Bank OperationalPolicies (OP) 4.01 –

Environmental Assessment and OP 4.11 – Physical Cultural Resources.

Methodology

Scoping Method

The scoping exercise has identified the activities that have the potential to interact with the

environment. The scoping consisted of the following:

Collection and review of the existing documents relevant to the proposed project

Collection and review of environmental and socio-economic data relevant to the proposed

project,

Review of relevant legislative requirements, national and international environmental

standards and guidelines pertinent to the project and,

Consultation with project stakeholders and other potentially interested and affected parties.

The scoping assisted in the identification of gaps and setting the scope of the work.

Baseline Investigation Methods

The synthesis of the environmental and socio-economic data of the project area was undertaken

through accomplishing a number of tasks.

Pertinent data from relevant institutions were collected and critically evaluated before the

baseline survey. Published regulations, guidelines, national policy papers and documents as well

as World Bank guidelines for wastewater treatment and general ESIA study were reviewed.

Site visits were made to collect data and update baseline information of the project area.

Observations were made on biophysical and socio economic aspects. Photographic images that

depict key environmental features were taken and GIS was used. Effluent and related water

samples were collected and analyzed. House-to-house survey (total numeration) was conducted

along the 18kms sewer line to address the socioeconomic impacts and prepare the RAP. Field

observations in the downstream areas were also conducted.

During the field visits, discussions were held with local community, community leaders and key

informants in the affected districts. Opinions and attitudes of PAPs were assessed through

questionnaires, Key Informant Interviews and Focused Group Discussions. Furthermore,

consultations with Addis Ababa and Federal EPA and AAWSA were made.

The environmental and social impacts of the project were identified by considering all proposed

activities during the mobilization, construction, post-construction, operation and

decommissioning phases and the concerns and issues raised by stakeholders. The interactions


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(impact) of each activity with the environmental and socio-economic receptors were assessed

using a matrix. Impact evaluation were made using the following key elements:

Spatial Scale (site specific, local, city wide)

Duration (short term, medium term and long term)

Reversibility (reversible, irreversible)

Probability (the likelihood that an activity will occur)

Direction beneficial or adverse)

Significance (low, medium, high)

II. Polices, Legal, Institutional and Administrative frame work

National and international environmental policies, standards, regulations and guidelines provide

a framework for the current ESIA Study. Therefore, relevant policies, legislations and

regulations were reviewed.

National policy and regulatory frame work

The Constitution of the Federal Democratic Republic of Ethiopia, adopted in August 1995, has a

number of provisions, which have direct policy and legal relevance to environmental protection

matters in connection with development projects. The concepts of sustainable development and

environmental rights are entrenched in the rights of the people of Ethiopia through Articles 43

and 44. Among the important principles stated in the Constitution are the citizens’ right to

development and to live in a clean and healthy environment, the duty to protect the environment,

and the people’s right to full consultation and expression of views in the planning and

implementation of policies and projects that affect them directly.

The other important policy document is the Environmental Policy of Ethiopia (EPE), which has

an overall policy goal to improve and enhance the health and quality of life of all Ethiopians, to

promote sustainable social and economic development through sound management and use of

natural, human-made and cultural resources and their environment as a whole. The EIA policies

contained in the EPE emphasize the early recognition of environmental issues in project

planning, public participation, mitigation and environmental management, and capacity building

at all levels of administration.

In addition, the Ethiopian Government has issued a number of legislations that are aimed at

advancing environmental protection and sustainable use of the Country’s natural as well as man-

made resources. Among these laws, the most relevant ones include the Proclamation on

Institutional Arrangement for Environmental Protection, Proclamation on EIA, Proclamation on

Environmental Pollution Control, and Proclamation on Ethiopian Water Resources Management.

The Institutional Arrangement Proclamation is aimed at ensuring sustainable use of


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environmental resources, by assigning responsibilities to separate organizations for

environmental development and management activities on one hand, and environmental

protection, regulations and monitoring on the other, thereby avoiding possible conflicts of

interests and duplication of efforts.

The EIA Proclamation makes an EIA mandatory for specified categories of activities undertaken

either by the public or private sectors and is the legal tool for environmental planning,

management and monitoring. The planned Kaliti WTP has been assigned under the category of

projects that are likely to bring some adverse impacts and thus, require further ESIA. Therefore,

in accordance to this legislation, ESIA has been conducted to determine the project’s potential

impacts and to develop appropriate mitigation measures to avoid or minimize the significant

negative impacts to acceptable levels. The recommended mitigation measures are presented in an

environmental and social management plan (ESMP) which will be part of the project

implementation plan.

The Pollution Control Proclamation is based on the right of each citizen to have a healthy

environment, as well as on the obligation to protect the environment. Its primary objective is to

provide the basis from which the relevant ambient environmental standards applicable to

Ethiopia can be developed, and to make the violation of these standards a punishable act.

Proclamation No. 197/2000 provides legal requirements for Ethiopian water resources

management, protection and utilization. Its main objective is to ensure that water resources of the

country are protected and utilized for the highest social and economic benefits, to follow up and

supervise that they are duly conserved, ensure that harmful effects of water use is prevented, and

that the management of water resources is carried out properly.

Institutional and Administrative frame work

Addis Ababa is the largest as well as the dominant political, economic, cultural and historical

city of the country. It has the status of both a city and a state. It is the capital of federal

government and a sit of a number international organizations and institutions like AU, UNECA,

etc. The city is divided in to ten sub-cities. The sub-cities are sub-divided in to 99 Districts,

which are the smallest administrative units in the city.

The management of water supply and sewage disposal is the responsibility of AAWSA. Ministry

of Water and Energy (MoWE), Ministry of Health, and Environmental Protection Authority are

mainly responsible for quality control and regulatory aspects of pollution protection of water

bodies.

The Addis Ababa Environmental Protection Authority has the following duties and

responsibility within the Addis Ababa City boundary:


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Follow up the implementation of the national policy and laws;

Prepare regional environmental protection and directives and upon approval follow up

and supervise their implementation;

Regulate and follow up that any development shall conduct ESIA prior to the project

implementation and undertake review of the project ESIA;

Undertake environmental. auditing of industries for the safe disposal and management of

liquid and toxic wastes;

Prepare appropriate standards to protect the environment that include soil, water and air

as well as the biological system in the City.

Addis Ababa Water and Sewerage Authority (AAWSA)

AAWSA was first established through the proclamation no. 68/1971 G.C as Addis Ababa Water

and Sewerage Service Authority and it was reestablished through the proclamation no. 10/1995

G.C as Addis Ababa Water & Sewerage Authority. It has the power and responsibility of

supplying safe and adequate water as well as management of wastewater (sewage) and

sludge collection and disposal for the Addis Ababa City.

World Bank’s Safeguard Policies

The World Bank environmental assessment (EA) requirements are based on a three-part

classification system such as Category A, Category B, and Category C. A project designated as

Category A requires a full environmental assessment followed by Independent Environmental

Review. Category B projects require a lesser level of environmental investigations. Category C

projects require no environmental analysis beyond that determination.

The planned Kaliti WTP falls under Category B Project […its potential adverse impacts on

human populations or environmentally important areas are less adverse than those of Category A

projects] since it is likely that the adverse environmental and social impacts can be controlled to

acceptable levels by designing and implementing appropriate mitigation measures. Hence, as per

World Bank requirements, this ESIA has been prepared.

III. Salient features of Kaliti treatment plant and sewer line to be developed

About 49 million m3 of wastewater is annually generated in the city of Addis Ababa. Wastewater

is mainly of domestic origin with 13.4% industrial. Most of this grey water is disposed into the

rivers and streams flowing through the city, like the Akaki River.

AAWSA has two water treatment plants in Addis Ababa, one of which is the Kaliti WTP which

is located in southern Addis Ababa. In connection with this AAWSA planned to rehabilitate and

expand the Kaliti wastewater treatment system. This new project is expected to play important

role in enhancing the major wastewater treatment and disposal problems the city is facing. The


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project area (Kaliti sewer catchment) is dominantly confined in Bole, “Kirkos”, Akaki-Kaliti and

“Nefas Silk-Lafto” sub-cities. The treatment plant is located in the Akaki Kaliti sub-city,

“Kebele” 7.

The project has sewer collection part that extends into the city and that is to be expanded by

installing trunk sewer lines. The other important component of the project is the installation of a

new wastewater treatment plant with improved technology and treatment capacity. The third

important part of the project is the area downstream of the WTP which will be affected by the

effluent coming out of the treatment plant. Accordingly the project is subdivided spatially into

these three areas.

The Sewer Lines

The Akaki river basin has high elevation differences in the north–south direction, which is the

general direction of the proposed sewer line. This characteristic has been taken in designing the

new sewer line as a system that functions by gravity only. In most places, the new system

follows the alignment of the existing sewer line.

Three trunk sewer lines have been identified (Western, Eastern, and Main/southern Kaliti

Catchment Sewer Trunks) to be installed on phase-by-phase basis. In particular:

Western Trunk extends from the ring road at Kaliti to north of Lafto bridge and is supposed to

give service to the Western Kaliti Catchment.

Eastern Trunk extends from the ring road at Kaliti to Bole Bridge on African Avenue and will

give service to the eastern Kaliti Catchment (“Wollo Sefer” and “Bole Medahnealem” areas and

around “Nefas Silk”).

Southern Main Trunk is the line that extends from the ring road at Kaliti to the Kaliti WTP. This

trunk is proposed to twin the existing 800 and 700mm trunk mains.

The existing sewer trunk was originally provided with a utility right-of-way, which is encroached

on illegally over time by squatter settlements. This will necessitate much effort to establish a new

right-of-way and provide sufficient space for construction and access for future operation and

maintenance.

The proposed sewer lines (trunk lines) are expected to serve much the newly built southern and

south central Addis Ababa. The total length of the sewer line is 18kms.

Relation of Existing Sewer Line with the Proposed Sewer Line

The proposed sewer line is expected to pass parallel to the existing system in many places.

This may help to reduce the impact on infrastructures. However, a number of houses are illegally

constructed even on the existing sewer lines at some places. In most places, it is difficult to trace

the existing sewer line. This will necessitate tracing the old system before the construction of the


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new system to avoid damage.

In the southern trunk, the two systems pass parallel to each other until they join the treatment

plant. In the eastern trunk, the new system follows the existing system in the northern end and

diverges to the east to accommodate new inbuilt areas along the Kebena River. In the western

trunk area, the existing system extends far to the north and northwest. In much of the places the

two systems have the same alignment and in few places they cross each other. This demands

serious consideration during the construction of the new system.

Existing Wastewater Treatment Plant

The existing Kaliti Wastewater Treatment Plant is a lagoon treatment system built in the late

1970’s and commissioned in 1983. The Kaliti WWTP has a design capacity of treating 7,500

m3/day of wastewater and 3,500 kg/day of biochemical oxygen demand. This is equivalent to a

population of 50,000. The actual Kaliti site is large but most of the space is occupied by the

existing facultative and maturation ponds as well as the sludge drying beds. The treatment plant

consists of inlet screens and grit chambers, two settling cambers, and two parallel pond systems,

and eight drying beds. The hydraulic retention time of the wastewater in the stabilization ponds

is approximately 30 days at maximum flow rate and the effluent from the ponds flow by gravity

and is finally discharged to Little Akaki River. Some of the effluent is directed to small channels

and used to irrigate fields between the site and the river.

About 5,600 m3

of trucked waste per week arrives at the plant. This consists of a combination of

latrine and septic tank waste. This waste is simply dried in the drying ponds.

It is planned to keep the existing lagoons in operation during the construction of the upgrades

and to replace most of the existing infrastructure.

Proposed Technology for the New WWTP

The following treatment processes were evaluated in the feasibility study document:

Oxidation ditch

Trickling Filter

Upgrading the existing waste stabilization Lagoons

UASB with Trickling Filter

Moving Bed Bioreactor

Conventional Activated Sludge

Important factors considered to select the most appropriate technology or combinations of

technologies were:

The design treatment capacity of 100,000 m3/day

Space requirement for the proposed treatment capacity


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Average BOD concentration of 740 mg/L which corresponds to the BOD load of 74,000kg/day

Variation of the BOD load

The top ranked three technologies were Oxidation Ditch, Trickling Filter, and upgrading of the

existing waste stabilization lagoons. In terms of cost, upgrading of existing lagoon is the least

whereas the oxidation ditch was the highest. Trickling Filter stood second with an estimated

construction cost of ETB 1,246,356,500.

Based on these, the feasibility study recommended Trickling Filter process as suitable

technology which can provide the required amount of BOD removal and accommodate the

expected fluctuations in BOD loads.

The major planned activities in the project include:

Construction of a Trickling Filter treatment system as per the design;

Rehabilitate and/or modify the existing treatment infrastructure to increase life cycle

Cleaning of all of the existing facultative and maturation lagoons, dewater the collected bottom

sediment disposed the solid in a landfill,

Modify the lagoons for use as constructed wetlands for additional treatment enhancement;

Clean out the two northernmost sludge drying ponds and use this area for construction of the

thickeners and digesters;

Build new head-works trains including screens with smaller openings;

Install system for collection and dispose of solids collected from the screens and grit to minimize

nuisances;

Provide trucked waste disposal site and treat trucked waste with the anaerobic digesters ;

Remove the toilet and carwash and rebuild near the head-works so that their effluent flows can be

directly connected to the sewage treatment facilities;

Continue using sludge lagoons to dewater sludge;

Allow for future biogas recovery (by others) by making use of a standard rate anaerobic digester;

Abandon or demolish and remove structures that are no longer required or that do not have

sufficient capacity for the proposed treatment process;

Flare the biogas from anaerobic digesters until future methane capture systems are installed by

others;

The treated effluent is expected to be used for irrigation and when irrigation is not required, it is

to be discharged into the river. To meet irrigation needs, the treated effluent treatment levels

have been set in conjunction with various factors such as protection of human health, protection

of the environment (river and crops to be irrigated), etc. within the constraints of the

technologies selected.

Wetlands have been designed to remove pathogens and particularly helminth eggs to meet

recommended treatment levels for irrigation usage.


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The proposed series of treatment processes is very interesting and designed in suitable manner to

adapt to the specific situation. It comprises a centralized and integrated sewer collection system

and a single WWTP. It will be constructed where the existing plant structures are located.

The selected technology will consist of the following units/processes:

Intake structure

(Bar screen, Grit chamber

Primary Clarifiers

Up Flow Anaerobic Sludge Blanket (UASB) Process

Trickling filters

Secondary clarifiers

Anaerobic sludge digesters

Constructed Wetland (Tertiary Treatment)

Thickening and Stabilization of Sludge

Sludge drying beds

Biogas system

Downstream Areas from the Treatment Plant

West of the treatment plant the area is mainly occupied by vegetable gardens and grassland. The

local community is growing vegetables (mainly cabbage) in these areas. The Little Akaki River

seems to be more polluted than the water being released from the treatment plant. Interviewed

people in downstream areas stated that the river water is much polluted and they are not

interested to use it even for irrigation compared with the effluents from the treatment plant.

Much of the open ground which was considered as command area in the irrigation feasibility

document is now occupied by many houses. There are many mud houses along the right bank of

the Little Akaki River. The vegetable gardens along the course of the river are owned by the

residents of these areas.

The course of the little Akaki River is highly vegetated. This becomes important habitat for birds

and animals. Some of the trees (eucalyptus) are owned by local residents. The presence of the

treatment plant has favored the growth of different vegetation in the area.

IV. Impact categories of the treatment plant and sewer line development

Impacts arise due to the interaction of the project with the environment and the society. The

interaction of the project can come from the project location and from the various activities of

the project in the different phases. The receptors are the physical and the biological environments

and the society.


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Biophysical Impacts

This category of impacts includes impacts on air, water, land, flora and fauna.

Impacts on air quality

The impact on air quality comes from dust emission because of excavation works,

construction materials transport and handling, dust generation by vehicular movement,

vehicular emission, and emission of gases from the treatment plant during its operation.

The emissions of air pollutants include airborne particulates (dust), fugitive emissions, exhaust

and combustion emissions.

The composition of dust is often inorganic and of non-toxic nature. The vehicular emissions

constitute such gaseous pollutants as oxides of nitrogen, sulfur dioxide, carbon monoxide, CO2,

some unburned hydrocarbons. The dust may accumulate on the ground and on vegetation nearby

while the gasses may disperse and get diluted.

The potential effects are influenced by the weather conditions (rain and wind direction) and by

preventive measures implemented during construction to minimize emissions. These include:

Impacts on water

The impacts can be on surface water or ground water and can be adverse or beneficial. Adverse

impacts on water quality can be through increased sediment load as a result of the construction

activities. Fuel leakages from storage tanks or vehicles and inappropriate disposal of wastes can

cause pollution incidents. Leakage can be from sewage pipes, from the WTP during operation,

from sludge production, and uncontrolled release of waste. Contamination will result when

theses pollutants are transferred to water bodies through leaching and washing. There may be

contamination of Little Akaki river due to run off, overflow and leakage from such units if there

happen operation and maintenance failure or other unprecedented environmental calamities.

Beneficial impact on water bodies result from the collection and treatment of sewage that is

currently discharged haphazardly and that is polluting the environment including water bodies.

Impacts on land

The impacts on land include changes in land use and land cover especially upstream of the WTP.

The installation of the sewer trunks and the institution of the buffer zone will impact the current

land use and land cover. Site clearing and excavation activities, particularly on steep slopes, on

or near riverbanks during minor and major drainage works, and furrow ditch constructions can

lead to erosion and slope instability. Removal of vegetation, trees and shrubs, particularly in

sloppy areas may bring soil erosion and land slide.


xxii


The impacts on soil are due to soil erosion and soil contamination by leaked substances, littering

and irresponsible disposal of waste.

Impacts on flora and fauna

Loss of vegetation and trees may result due to site clearing activities within the existing Kaliti

WTP site but mainly upstream of the treatment plant in the sewer trunk area, along riversides,

inside residential houses, near fences, inside institutional compounds and forest sites. Unwise

and inappropriate dumping of soils in the forest sites may aggravate the loss of forest tree

species. The impact will include loss of vegetables and crops planted by people residing on the

riverside.

Socio-economic impacts

Job creations and emergence of small business activities around the plant are the main beneficial

socio-economic impacts. Increase in the number of people and industries to be served by sewer

network, use of flush toilets instead of pit latrine, avoiding odor and visual nuisance due to open

and uncontrolled release of wastewater from domestic and industrial facilities are possible

benefits. The WTP development will provide water of a quality for irrigation to the downstream

area. The sludge can also serve as soil fertilizer.

There will be property loss (houses, farmlands, trees, fences, etc) in some areas. The project

work can cause temporary disruption to residential area at a small section of the “Bole Bulbula”

sewer area. Asphalted and non-asphalted roads will be dug at few places where the sewer line

crosses the roads.

Noise pollution

The noise pollution can be from operation of heavy machinery and excavation equipments

during excavation work and construction, due to loading-unloading operations, material

handling, machine operation, equipment & vehicular movement. Pumping station, diesel

generator and flaring activities also create noise.

Safety

Exposure to hydrogen sulfide, spills, process upset, natural hazards, power failures, fires, injury

and accidents of various nature are among the safety concerns.


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V. Main impacts and proposed mitigation measures

Main Adverse Impacts and Mitigation Measures

Receptor Impact Mitigation Measure

Sewer trunk Part of the Project

Soil

excavation/trenching • Reduction of soil erosion by limiting excavation and

other earthworks to dry seasons (if possible)

• Covering the trench as soon as possible

• collecting the excess excavated soil and dumping in

pre-planned sites

• Implement erosion prevention mechanisms

Flora

site clearing • awareness creation to the workers

• building soft communication between the residents and

workers

• encouraging residents to collect their vegetables before

the project activities

vegetation removal • implement replanting program

• Only marked trees are to be felled within the sewage

trunk main alignment

Water

soil erosion/siltation-

excavation/trenching • covering the trench as soon as possible

• collecting the excess excavated soil and dumping in

pre-planned sites

• Implement erosion prevention mechanisms

• Limiting the excavation and other earth works to the

dry season (if possible)

• Installing silt traps during construction

Socio-

economy

Property loss

Some persons will be displaced • A compensation and resettlement plan has been

prepared for project affected persons who will be

relocated as a result of the intervention. This covers

all costs of loss of properties. Such compensation and

resettlement plan will be completed before the start of

construction.

Health and

Safety

Accidents loading and unloading

operations, reversing machinery,

falling from culverts, in trenches,

• Provision and using of protective wear

• Appropriate warning signs shall be placed in areas

where accidents are expected to occur

• Strict prohibition of operation of equipment by

unauthorized personnel

• isolating the work areas

• following safety procedures, including ongoing

awareness campaign among contractors and

surrounding communities.

• introducing a traffic plan with speed and traffic


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regulation

STD, HIV/AIDS • Awareness creation on HIV/AIDS and other STDs

among project implementers and surrounding

community

Others

Saudi Arabia Embassy • The client decided to realign the sewer line

Behere Tsige Park • Only marked trees are to be felled

• Implement a plantation program

Mosque (fence) • The client decided to realign the sewer line

Existing sewer system • Discovering the existing sewer line prior to

excavation

Wastewater Treatment Plant

Air Quality

Odor from septage receiving station,

grit removal chambers, trickling

filter, anaerobic digesters, sludge

handling systems, etc.

• Unpaved access roads shall be regularly water sprayed

• Setting low speed limits on unpaved access road

• Preventive maintenance of vehicles and construction

equipment

• proper housekeeping procedures (regular cleaning of

the grit and screenings)

• proper operational practices including process control

and chemical treatment

• continuous process of the operation

• Running the UASB at optimum condition

• Planting shrubs and trees along the periphery

• Use of personal protective equipment (e.g. masks),

when necessary

Soil/land

sewage overflow • Efficient drainage system for leachate and flood

protection structures must be constructed

• provision of buffer zones between the plant and the

rest,

• proper planning of the project operation and

maintenance,

• proper implementation of the Environmental

Management Plan.

Unsafe sludge disposal • dispose sludge with dangerous substances in sanitary

landfill

loss of original function •

Water

sewage overflow • sludge should be properly disposed in a sanitary landfill

• Connection of untreated/substandard industrial

wastewater to the sewer line must be strictly prohibited.

• Adequate care should be taken to avoid leakages in the


xxv



plant.

• All pipe work and fittings should be a class rating in

excess of the maximum pressure attained in service

including any surge pressure.

Unsafe sludge disposal • dispose sludge with dangerous substances in sanitary

landfill

Flora vegetation removal • Demarcation and fencing off the construction areas

Health and

Safety

Accidents • giving orientation to workers about safety procedures

• Provision and using of protective wear

• Appropriate warning signs shall be placed in areas

where accidents are expected to occur

• Strict prohibition of operation of equipment by

unauthorized personnel

• isolating the work areas

• following safety procedures

• erecting traffic signs in the WTP site

• availing first aid services

STD, HIV/AIDS • Awareness Creation on HIV-AIDS and STDs among

workers and surrounding communities

Health risk • provision of buffer zones between the plant and the

rest,

• proper planning of the project operation and

maintenance,

• proper implementation of the Environmental

Management Plan

Area Downstream of Wastewater Treatment Plant

Water

inappropriate waste disposal

Unlined drying beds • The whole treatment should avoid leakages of

wastewater to groundwater

• Sludge drying beds should be impermeable

• temporary sludge disposal sites should be impermeable

and protected from flood

• Only partly divert treated water for irrigation use not to

significantly reduce the discharge into the Little Akaki

River

sewage overflow • Efficient drainage system for leachate and flood

protection structures must be constructed


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Summary of Main Positive Impacts

Receptor Impact

Sewer trunk Line Part of the Project

Water Reduction of contamination of surface and ground water

Soil Reduction of contamination of soil

Socio-economy

Employment

Improved habitability of the City

improved public health


Water Reduction of contamination of surface and ground water

Soil Reduction of contamination of soil

Socio-economy

Employment

Improved habitability of the City

improved public health

Biogas for energy use

Sludge for fertilizer use

Sludge for electricity generation through pyrolysis


Air quality improved air quality

Soil/land improved fertility

Water surface/underground improved water quality of Little Akaki

Availability of water for agricultural and industrial use

Flora more vegetation due to increased fertility and availability of cleaner water,

healthier vegetables

Socio-economy more income due to improved farming

cleaner environment

Health and Safety improved public health

VI. Environmental and social management and monitoring plan

ESMP is the key to ensure that the environmental quality of the project area does not deteriorate

due to the implementation of the proposed development project. Environmental monitoring is an

essential tool in relation to environmental management as it provides the basis for rational

management decisions regarding impact control. Monitoring should be performed during all

stages of the project (namely: mobilization, construction, post construction, operation and

decommissioning) to ensure that the impacts are no greater than predicted, and to verify the

impact predictions.


xxvii


The ESMP for the Project has been developed to meet long-term objectives of the project

activities and operations. The ESMP is designed to guarantee and achieve the implementations of

the ESIA findings highlighted in this report through the provision of project execution and

mitigation guidelines, monitoring plan, responsibilities and training procedures. The plan

provides a general outlay of the activities, associated impacts, mitigation action plans and

appropriate indicators for monitoring. Implementation timeframes and responsibilities are

defined, and where practicable, the cost estimates for recommended measures are provided. The

ESMP has also proposed institutional arrangement for its implementation.

VII. Cost estimate of the proposed mitigation measures

A summary of the environmental management and compensation costs is given in the following

table.

Category Individual Cost Category Cost

RAP

Implementation 18,368,609.23

18,454,002.23 Administrative 85,393.00

EMP

mitigation and enhancement 440,000

850,300 Monitoring and training 410,300

Total 19,304,305

About 95.6% of the total cost is for compensation/RAP.

VIII. Conclusions and Recommendations

Conclusions

The Kaliti WTP which started operating in 1983 has a design capacity of about 7,500 cubic

meters per day. The present coverage of the wastewater management of the city is not greater

than 9.8%. The existing sewer lines cannot accommodate the high volume of sewage waste.

Sewage overflows on to streets, and into the watercourses. Sewage from septic tanks and latrines

pollute groundwater. There is open wastewater disposal. Illegal connections of sewerage to storm

drainage lines are not rare. This situation is affecting the public health and the aesthetics of the

city. In light of these, the need for an improved wastewater treatment plant and collection system

is indisputable.

The preference for use of gravity system for sewage collection is commendable since it will

avoid problems associated with power interruptions and will minimize the operating cost of the

sewer lines. The analysis of various alternatives carried out indicates that selected options/routes

are appropriate.

The new plant will have a capacity to treat 100,000m3/d, which is more than 13 times greater

than the existing capacity. The new sewer trunks that will be built will relieve the existing sewer


xxviii


lines. The comparison of the selected technology for the Kaliti WTP with other technologies has clearly shown that

the selected process combination of Kaliti WTP is very good in terms of technical,

environmental, economic and socio-cultural performance criteria.

Most of the environmental impacts identified in the sewer trunk line area, are of minor to

medium significance and of short-term duration. As regards the socio-economic impacts, both

positive and negative impacts have been identified. The negative impacts include land, property

and social issues. Moreover, the PAPs have shown positive attitude for the project so far as they

get proper compensation. Accordingly, a compensation and resettlement action plan with a

grievance accommodation mechanism has been developed to respond for the PAPs.

Many of the adverse environmental and socio-economic impacts in the WTP site are minor and

can be mitigated.

Downstream of the WTP, the impacts are mainly positive. There is no existence of endangered

species of flora and fauna in the project area. The proposed project will give a long-term solution

to the sewage disposal needs of Addis Ababa. With proper maintenance and environmental

monitoring, the project is not expected to have adverse effects on the environment and on the

surrounding community.

The positive impacts by far outweigh the negative impacts. The implementation of the project

will improve the health and livelihood of the city residents and downstream users of polluted

river waters as it reduces the prevalence of waterborne diseases.

After a careful review of the design document and the existing and generated environmental

baseline data, the consultant has come to the conclusion that it is possible to mitigate almost all

of the environmental and socio economic impacts due to the implementation of the proposed

project with about ETB 19,305,000 (compensation and environmental and social management

and monitoring plan).

Recommendations

Therefore, it is recommended to implement the project with strict observation to the

environmental and social management and monitoring plans.

However, the project supervision consultant once mobilized should prepare “Construction

Supervision Plan” before the beginning of construction works and this plan should be part of the

contract. In addition, the environmental management plans should be made part of contract

documents of contractor so that ESMP compliance is ensured.


1


1. INTRODUCTION

The project focuses on the environmental and social impact assessment (ESIA) of the Kaliti

wastewater treatment plant and sewer line expansion and rehabilitation project. Spatially three

important components exist. These are the treatment system, the new sewer lines and the immediate

areas downstream of the treatment plant. The present study is a full-fledged ESIA covering the

biological, physical and social environments conducted as per the requirements the

regulations/legislations and environmental policy of Ethiopia and the World Bank Safeguard

Policies.

1.1 Background

The population of Addis Ababa City and provision of water supply and other socio economic

developmental activities are increasing from time to time. The amount of domestic and industrial

wastewater generated is also increasing. Currently, there is a sewerage system and a wastewater

treatment plant serving some parts of the city in the Kaliti catchment. These include Bole, “Ledeta”,

Old Airport, “Arada”, “Kirkos”, Mekanisa and “Kera” areas. Nevertheless, the present coverage of

the wastewater management of the city is not greater than 9.8%.

The existing sewer lines in this catchment cannot accommodate the high volume of sewage waste.

As a result, sewage overflows on to streets and into water courses.Septic pump-out trucks do not

access all areas to service the new high volume customers. Sewage from septic tanks and latrines

continue to pollute groundwater. There are uncontrolled and open wastewater disposal, illegal

connections of sewerage to storm drainage lines and to nearby rivers. The situation is affecting

public health and aesthetics of the city.This situation has become one of the major challenges of the

city of Addis Ababa. It will remain a big problem for the years to come unless proper interventions

are made.

In order to alleviate this problem, Addis Ababa Water and Sewerage Authority (AAWSA)has

embarked on a project for study and design of wastewater collection, treatment and disposal systems

in the Kaliti catchment area.

Following the design and rehabilitation of the existing wastewater facility, AAWSA invited

consultants to bid for environmental and social impact assessment of the Kaliti wastewater treatment

and sewer line rehabilitation and expansion project. Beles Engineering PLC has won the bid and

started the ESIA study of the project. This document is the final report of the ESIA (Volume I). The

work also includes Resettlement Action Plan (RAP), which is presented in volume II.


2


1.2 Objective of ESIA study

1.2.1 General Objective

The general objective of the study is to conduct detailed environmental and social impact assessment

of the wastewater treatment plant and sewer line rehabilitation and expansion within the Kaliti

catchment.

1.2.2 Specific Objectives

The specific objectives are:

To define and evaluate the immediate and long term environmental impact of the proposed project on

the physical, biological and socio economic/cultural environment at different phases of the project

development;

To propose mitigation measures and prepare environmental management, environmental monitoring

and resettlement action plans.

To assess the viability of Kaliti wastewater treatment plant and sewer line expansion in line with

environmental and social point of view for subsequent action by decision makers

1.3 Scope of the Study

The present report is based on Terms of Reference (TOR) provided to the consultants as part of their

contract document. The report is prepared taking into account the guidelines of the FDRE

Environmental Protection Authority and the World Bank Operational Policy (OP) 4.01 –

Environmental Assessment.

The scopes of work of the present EIA study were as follows.

Conduct environmental baseline survey;

Identify environmental and social components likely to be impacted by the project;

Assess and evaluate of impacts;

Conduct public consultation to obtain people’s perception about the project;

Propose Mitigation measures;

Prepare RAP;

Prepare detail Environmental and Social Management Plan (ESMP);

Prepare detail Environmental Monitoring Plan (EMP);

1.4 Methodology

1.4.1 Scoping Method

The scoping exercise has identified the activities that have the potential to interact with the

environment. The scoping consisted of the following:

Collection and review of the existing documents relevant to the proposed project (project design

documentation, similar projects implemented elsewhere through literature review),

Collection and review of environmental and socio-economic data relevant to the proposed project,


3


Review of relevant legislative requirements, national and international environmental standards

and guidelines pertinent to the project and,

Consultation with project stakeholders and other potentially interested and affected parties.

Description of the project action including a clarification of the purpose and rationale of the project,

and an understanding of its various characteristics including the stages of development, location and

processes were performed through document review during the scoping process.

The scoping assisted in the identification of gaps in the environmental and socio-economic

information that needed to be addressed. This in turn led to the formulation of an informed impact

assessment in the subsequent ESIA process.

1.4.2 Baseline Investigation Methods

Following scoping, environmental and socio-economic data were assessed in more detail to ensure

that all of the proposed activities and their consequences were considered in full. The synthesis of the

environmental and socio-economic data of the project area was undertaken through accomplishing

the following main tasks.

i. Collection of Secondary Data and Desk Study

Pertinent data from relevant institutions were collected and critically evaluated before the baseline

survey. The client availed all pertinent documents that include the detail design of the proposed

wastewater treatment system, rehabilitation and expansion project. In addition, at the federal level,

published regulations, guidelines, national policy papers and documents as well as World Bank

guidelines for wastewater treatment and general ESIA study were reviewed.

ii. Field Investigation

Site visits were made to collect data and update baseline information of the project area, with special

attention to the Kaliti waste water treatment plant, proposed sewer lines and downstream areas by

giving due emphasis to the social and biophysical environments that are likely to be affected directly

by the project. Observations were made on biophysical and socio economic aspects such as soil,

water resources, topographic feature, present land use, vegetation cover, settlement pattern, public

infrastructures etc. Pictures that depict key environmental feature were taken and incorporated in this

report. Effluent and related water samples were collected and analyzed in laboratory. House-to-

house survey (total numeration) was conducted along the 18kms sewer line by taking buffer zone of

6 meters from the center of the sewer line to address the socioeconomic impacts and prepare the

RAP. Downstream areas were also visited.

iii. Consultation with the Stakeholders and the Public

During the field visits, discussions were held with local community, community leaders and key

informants from affected District to update the baseline information and obtain their views about the

project implementation. Furthermore, consultations with Addis Ababa and Federal EPA and

AAWSA were made on relevant environmental topics related to project ESIA review, monitoring

and supervision of effluents from industrial facilities and about their capacity to undertake routine

water quality monitoring during the Wastewater Treatment Plant (WTP) operation.


4


1.4.3 Environmental and Socio-economic Impact Assessment Methodology

Identification of key impacts brings together the previous steps with the aim of ensuring that all

potentially significant environmental impacts (adverse and beneficial) are identified and taken into

account in the process.

To identify the project environmental and social impacts, all proposed activities during the

mobilization, construction, post- construction, operation and decommissioning phases of the project

have been considered. In addition, concerns and issues raised by members of the community and/or

project stakeholders during consultation were included in the process.

Following identification of all project activities, environmental and socio-economic receptors were

identified (Tables 1.1- 1.3). The key inputs for the identification of receptors included the legislative

review, the environmental baseline, the socio-economic baseline and stakeholder consultation.

Table 1.1: Physical environmental receptors

Physical

Receptors Description

Air Air quality in and around the proposed project development sites

Surface water The surface waters in which project activities are proposed to occur

Soil The soils of areas in which project activities are proposed to occur

Land Landforms that can be modified by earth moving machines and

construction.

Table 1.2: Biological environmental receptors

Biological


Flora Plant species that occur in areas where project activities are proposed

to take place

Terrestrial fauna Animal species that inhabit the terrestrial habitats where the project

activities are proposed to occur

As previously described, the environmental and socio-economic baseline data were compiled using a

combination of existing data and the results of baseline survey and stakeholder consultation

programs. All key issues that were raised by members of the community or by a stakeholder group

during the consultation program to date, were recorded and included as environmental and socio-

economic impact regardless of the scientific, commercial or factual validity of the claim. In this way,

it is assured that the ESIA process has addressed every community and/or stakeholder concern.

Table 1.3: Socio-economic environmental receptors

Socio-economic


Population growth Population growth will take place within the project site

Employment Employment opportunities are the perceived benefits within the

project site and the nearby areas.

Access to modern sewage system Part of the city will have better access to sewage services

Economic development Promotion of various small and micro businesses

Resettlement Dislocated people will resettle


5


Socio-economic


Social organizations could be disrupted

Vulnerable people Aged and orphans are vulnerable

Diseases Incidence of communicable diseases

Through such steps, the activities involved in the development of the project and the possible

interactions of each activity with the environmental and socio-economic receptors were assessed

using a simple matrix.

In the prediction and evaluation stage, estimates of the magnitude of impact over each of the impact

variables identified during different phases of the projects’ lifecycle were made. In assessing the

level of impact that an activity may cause, five key elements are considered.

Spatial Scale (site specific, local, city wide)

Duration (short term, medium term and long term)

Reversibility (reversible, irreversible)

Probability (the likelihood that an activity will occur)

Direction beneficial or adverse)

Significance (low, medium, high)

Table 1.4: Criteria used in the evaluation of impacts

CRITERIA SIGNIFICANCE

Spatial scale Site specific Local City wide -

Duration Short term Medium term Long term Permanent

Probability of Occurrence Improbable Possible Highly Probable certain

Significance None Low Medium High

The criteria are defined as follows:

i. Spatial Scale: Site specific (restricted to the site) Local (the site and surrounds), City wide (affecting

parts of the city).

ii. Duration: Short-term (up to 1 year), medium-term (1 year to 2 years), long-term (life cycle of the

project) or permanent.

iii. Probability of occurrence: Improbable (unlikely), probable, highly probable or definite (certain).

iv. Significance: Based on a synthesis of the information contained in (i) to (iii) above, and taking

mitigation measures into account, an evaluation of the significance of the impact is undertaken in

terms of the following significance criteria:

No significance-requires no further investigation and no mitigation or management;

Low Significance -an impact which has little importance and is not sufficient to warrant further

reduction if this involves unreasonable cost.

Medium Significance -an impact which should be mitigated, if possible, to reduce it to

acceptable levels;

High significance -an impact which requires extensive mitigation and management to reduce

impacts to acceptable levels.


6


The environmental and social management and monitoring plans for the proposed project consist of a

set of mitigation, monitoring, and institutional measures to be taken during all phases to eliminate the

adverse environmental and social impacts identified and predicted, offset them, or reduce them to

acceptable levels. The plans also include the actions and resources needed to implement these

measures.

Estimation of costs for various mitigation, monitoring, and institutional measures were performed

based on the current knowledge of the issues and market prices.


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2 POLICY, LEGISLATION AND ADMINISTRATIVE FRAMEWORK

2.1 Institutional Arrangements

The current system of government in Ethiopia is organized into a federal structure, comprised of a

federal government and nine regional states. Government administration of EIA in Ethiopia is thus

shared between the federal government and regional states.

The environmental protection institutions in Ethiopia are established through the Environnemental

Protection Organs Establishment Proclamation (No 295/2002). According to this proclamation, the

protection organs include the Environmental Protection Authority (now the Ministry of Forest and

Environment), Regional Environmental Agencies and the Sectoral Environmental Units.

2.1.1 National Environmental Protection Authority

The National Environmental Protection Authority (EPA) was re-established under Proclamation No.

295/2002 as an autonomous public institution of the Federal Government of Ethiopia entrusted with

the protection and conservation of natural resources in Ethiopia. The general role of the EPA is to

provide for the protection and conservation of the broad environment, through formulation of

policies, strategies, laws and standards, which foster social and economic development in a manner

that enhance the welfare of humans and the safety of the environment sustainable.

The federal EPA was an independent organization accountable directly to the Office of the Prime

Minister. The key functions of the EPA are:

Prepare environmental protection policy laws and ensure their implementation;

Prepare directives and devise systems and ensure their implementation;

Prepare environmental protection standards directives concerning soil, water and air;

Enhance environmental awareness and training programs;

Ensure the implementation of international treaties concerning the environment to which Ethiopia is a

signatory;

Provide advice and technical support to the regions on environmental matters;

EPA is responsible for:

establishing a system for undertaking EIA

developing a directive that identifies categories with negative impact

issuing guidelines on EIA preparation and evaluation

Evaluating EIA study reports, and

Auditing and regulating EIA implementation.

A new arrangement has been laid where the EPA has delegated the ESIA authority and entrusts to

the ministries (MoM, MoARD, MoWUD, MoH, MoTI, MoTC and MoWE).

All the duties and responsibilities of the Federal EPA are now assumed by the new Ministry of

Forest and Environment.

2.1.2 Regional Environmental Agencies

These are established by national regional states as per Proclamation No. 295/2002.The national


8


regional states can also designate an existing agency that shall, based on the Ethiopian

Environmental Policy and Conservation strategy and ensuring public participation in the decision

making process, be responsible for coordinating the formulation, implementation, review and

revision of regional conservation strategies, and environmental monitoring, protection and

regulation. These are responsible for evaluating the EIA study reports on projects in regional states

and not likely to entail inter-regional impacts. Regional environmental agencies are also responsible

for auditing and regulating the implementation of such projects.

2.1.3 Sectoral Environmental Units

According to the Proclamation No. 295/2002, every competent agency shall establish or designate an

environmental unit that shall be responsible for coordination and follow up so that the activities of

the competent agency are in harmony with this Proclamation and with other environmental

protection requirements. However, sectoral environmental units have only been established in some

federal institutions, such as the Ethiopian Roads Authority, EEPCo and the MoWE.

The sectoral institutions relevant to EIA include:

The Ministry/Bureaus of Trade: Responsible for issuing business licenses,

Ethiopian Investment Agency and Regional Investment Commissions: Responsible for promoting,

coordinating and facilitating investment in the country,

The Ministry/Bureaus of Mines: Responsible for the development and proper utilization of mineral

resources in the country

Ministry/Bureaus of Agriculture: Responsible for both the development and management of natural

resources

Ministry/Bureaus of Water and Energy: responsible for the conservation, utilization and development

of water resources and energy in the country

2.2 National Policy and Strategies

2.2.1 The Constitution of the Federal Democratic Republic of Ethiopia (Proc. No.1 /1995)

The Constitution of the Federal Democratic Republic of Ethiopia (FDRE 1995), contains a number

of articles which are relevant to environmental matters in connection with development projects, as

well as to the environmental issues in general, and forms the fundamental basis for the development

of specific environmental legislative instruments related to development projects. Some of the

prominent Articles that are related to development and environment include (but not limited to) the

following:

Article 43 gives the right to people to improved living standards and to sustainable development.

Article 44 of states that all persons have the right for clean and healthy environment

Article 92 of Chapter 10 includes the following significant environmental objectives:

Development projects shall not damage or destroy the environment

People have the right to full consultation and the expression of views in the planning and

implementation of environmental policies and projects that affect them directly

Government and citizens shall have the duty to protect the environment


9


Article 40 states that ownership of both urban and rural land is vested in the State and the people, and

is common property which is not subject to sale or other means of exchange. Peasants have the right

to obtain land without payment, and are protected against eviction from land in their possession. Full

right to immovable property and permanent improvements to land is vested in individuals who have

built the property or made the improvements, but government may expropriate such property for

public purposes, subject to the payment in advance of compensation commensurate to the value of the

property or alternative means of compensation, including relocation with adequate State assistance.

The proposed project is designed to put in to effect some of the elements in the constitution that are

related to creating clean environment.

2.2.2 Conservation Strategy of Ethiopia (1997)

The major environmental and natural resources management issues facing Ethiopia are documented

in the Conservation Strategy of Ethiopia. It provides a strategic framework for integrating

environmental planning into new and existing policies, programs and projects. It is an important

policy document, which views environmental management from several perspectives. In particular,

it recognizes the importance of incorporating environmental factors into development activities from

the outset, so that planners may take into account environmental protection as an essential

component of economic, social and cultural development.

2.2.3 Environmental Policy of the Federal Democratic Republic of Ethiopia (1997)

It is based on the Conservation Strategy of Ethiopia (CSE), which was developed through a

consultative process over the period 1989-1995. The policy has the broad aim of rectifying previous

policy failures and deficiencies, which in the past, have led to serious environmental degradation. It

is fully integrated and compatible with the overall long-term economic development strategy of the

country, known as Agricultural Development-Led Industrialization (ADLI), and other key national

policies. The Environmental Policy has an overall goal to improve the health and quality of the life

of all Ethiopians, and promote sustainable social and economic development by adopting

environmental management principles, and key elements of the policy are:

recognition of the need for ESIA to address social, socioeconomic, political and cultural impacts, in

addition to physical and biological impacts

incorporation of impact containment measures within the design process, and for mitigation measures

and contingency plans to be incorporated within environmental impact statements (EISs)

creation of an ESIA process legal framework with a coordinated institutional framework for the

execution and approval of ESIAs and environmental audits, and

development of detailed technical sectoral guidelines for ESIA and environmental auditing, and

ESIA and auditing capacity building within the EPA, sectoral ministries and agencies, as well as in

the regions.

2.2.4 National Policy on Biodiversity Conservation and Research (1998)

This provides for an Institute that undertakes conservation and promotes the development and

sustainable utilization of the country’s biological resources including plants, animals and microbial

genetic resources. On the basis of national legislation, the institute has the responsibility and duty to


10


implement international conventions, agreements and obligations on biodiversity to which Ethiopia

is a party.

2.2.5 Sectoral Policies

2.2.5.1 Ethiopian Water Resources Management Policy (MoWR 2000)

The main goal of the Ethiopian Water Resources' Management Policy is to enhance and promote all

national efforts, equitable and optimum utilization of the available water resources of Ethiopia for

significant socio-economic development on sustainable basis without affecting the environment

significantly. The main objective of the water supply and sanitation policy is to enhance the well-

being and productivity of the Ethiopian people through provision of adequate, reliable and clean

water supply and sanitation services and to foster its tangible contribution to the economy by

providing water supply services that meet the livestock, industry and other water users' demands.

The policy gives highest priority to allocation of water for water supply and sanitation while

apportioning the rest for uses and users that result in highest socioeconomic benefits. It also

recognized that the basic minimum requirement, as the reserve for human and livestock needs as well

as environment reserve has the highest priority in any water allocation. The policy also gives

environmental considerations in the EWRMP with respect to pollution control, quality standards, and

limits of quantities of utilization. Thus, all water resource development projects shall undertake

environmental impact assessment (ESIA).

2.2.5.2 National Health Sector Strategy (1995)

The national health strategy focuses on communicable diseases, common nutritional disorders and on

environmental health and hygiene, in particular epidemic diseases like malaria and STDs,

particularly HIV/AIDS. Education on health care and sanitation through information, education and

communication, disease control, promotion of primary health care by community participation are

integral to the implementation of the strategy.

2.2.5.3 National HIV/AIDS Policy

Ethiopia is one of the countries in the world that is facing HIV/AIDS pandemics. Having understood

the magnitude of the HIV/AIDS pandemic and its paramount impacts on the socio-economic

development of the country, the FDRE issued a Policy on HIV/AIDS in 1998, which calls for an

integrated effort of multi-sectoral response to control the epidemic. The National HIV/AIDS Policy

urges communities at large, including government ministries, local governments and the civil society

to assume responsibility for carrying out HIV/AIDS awareness and prevention campaigns. The

general objective of the policy is to provide an enabling environment for the prevention and control

of HIV/AIDS in the country. In order to address the problem and coordinate the prevention and

control activities at national level, in 2000 National AIDS Council was established under the

Chairmanship of the country’s President, and in 2002 HIV/AIDS Prevention and Control Office was

established.


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2.2.5.4 National Population Policy

This Policy was issued in April 1993 and aims at closing the gap between high population growth

and low economic productivity through a planned reduction in population growth combined with an

increase in economic returns. With specific reference to natural resources, the main objectives of

National Population Policy include making population and economic growth compatible and the

overexploitation of natural resources unnecessary; ensuring spatially balanced population

distribution patterns, with a view to maintaining environmental security and extending the scope of

development activities; and maintaining and improving the accommodating capacity of the

environment by taking appropriate environmental protection and conservation measures.

2.2.5.5 National Policy on Women

This Policy was issued in March 1993 emphasizing that all economic and social programs and

activities should ensure equal access of men and women to the country’s resources and in the

decision making process, so that they can benefit equally from all activities carried out by the

Federal and Regional Institutions. Among the main policy objectives is that laws, regulations,

systems, policies and development plans that are issued by the government should ensure the

equality of men and women, and that special emphasis should be given to the participation of rural

women.

2.3 Relevant Environmental Legislations and Regulations

2.3.1 Proclamation for the Establishment of Environmental Protection Organs No. 295/2002

This proclamation established a system that fosters coordinated but differentiated responsibilities

among environmental protection agencies at federal and regional levels. It clarifies the mandate and

responsibilities of the Federal EPA and the Regional Environmental Authorities (REAs) within the

governments of the regional states. The proclamation insists that each. Sector office shall establish an

environmental unit to assess and evaluate environmental performance by the sector. In line with this

proclamation, AAWSA has Water Quality and Catchments Management Unit.

2.3.2 Proclamation on Environmental Impact Assessment No. 299/2002

This proclamation makes ESIA mandatory for specified categories of activities undertaken either by

the public or private sectors. The ESIA must be prepared by the proponent and reviewed by the

concerned environment organ. According to the Federal EPA, the following Project Schedule

categories are recognized:

Schedule 1: Projects that may have significant environmental impacts and therefore require detailed

field investigation and a full ESIA.

Schedule 2: These are projects whose type, scale or other relevant characteristics have potential to

cause some significant environmental impacts but are not likely to warrant a full ESIAstudy.

Schedule 3: These projects generally do not require environmental analysis because they have

negligible or minimal direct disturbance on the environment.

According to the Ethiopian EPA guidelines (EPA 2003), Construction of Municipal Sewage and

Wastewater Treatment Plant fall under Schedule 1 hence the Kaliti Sewer Catchments Wastewater


12


Treatment and Sewer line Expansion Project requires full ESIA.

2.3.3 Proclamation on Environmental Pollution Control No. 300/2002

This proclamation provides the basis for controlling wastewater discharges and developing

appropriate wastewater discharge standards, the violation of which would be a punishable act based

on the polluter pays principle. Environmental Inspectors are to be assigned by the concerned

environmental organ to monitor industrial effluent discharges. Guidelines for discharge standards

have been prepared for industrial, agricultural and domestic wastes (EP A 2003); national standard

limit of effluents has been prepared by EPA. The Addis Ababa EPA is presently approaching owners

of industrial facilities so as to plan for environmentally sound industrial wastewater treatment and

progressively reduce concentration of pollution load from each industrial facility.

2.3.4 Industrial Pollution Regulation No. 159 /2008

The Council of Ministers recently approved this Regulation to prevent industrial pollution in

accordance with Article 20 of the Environmental Pollution Control Proclamation No. 300/2002. The

Regulation provides a gestation period of five years for existing industries to bring their effluent

discharge within the water quality standards. The Addis Ababa EPA has planned to work with the

industrialists towards this direction.

2.4 Institutional and Administrative Framework

2.4.1 Administrative Framework

The Federal Democratic Republic of Ethiopia (FDRE) comprises nine member States and two

administrative councils with their own legislative, executive and judicial powers. For administrative

purposes, the States are divided into Zones, which are in turn sub-divided into Districts. Each

The management of water supply and sewage disposal is the responsibility of Addis Ababa Water

and Sewage Authority (AAWSA), Ministry of Water and Energy (MoWE), Ministry of Health, and

Environmental Protection Authority are mainly responsible for quality control and regulatory aspects

of pollution protection of water bodies. Ministry of Agriculture and the Urban Agriculture

Department under Addis Ababa City Administration are responsible for the provision of agricultural

extension services for peri-urban agriculture.

2.4.1.1 Addis Ababa City Administration

Addis Ababa is the largest as well as the dominant political, economic, cultural and historical city of

the country. It has the status of both a city and a state. It is the capital of the Federal Government and

a chartered city. It is where the African Union and its predecessor, the OAU are based. It also hosts

the headquarters of the United Nations Economic Commission for Africa (UNECA) and numerous

other continental and international organizations. The city is divided in to ten sub cities which are the

second administrative units next to city administration. In terms of area coverage,Bole is the largest

sub-city followed by “Akaki- Kaliti” and “Yeka”. “Addis Ketema” is the smallest and followed by

Lideta and “Arada” Sub-cities.


13


The sub-cities are sub-divided in to 99 districts, which are the smallest administrative units in the

city. The number of districts in each sub city varies based on their size.

Figure 2.1: Administrative sub division of Addis Ababa City

The city administration has a cabinet with executive power led by a Mayor. The sub cities are

organized in a similar fashion. They are mandated to administer matters in their jurisdiction, and

provide support to Districts. The Districts are empowered to administer local matters such as

community mobilization, neighborhood improvement and building code enforcement.

2.4.1.2 Addis Ababa Environmental Protection Authority (AA EPA)

The Addis Ababa Environmental Protection Authority has the following duties and responsibilities

within the Addis Ababa City boundary:

Follow up the implementation of the national policy and laws;

Prepare regional environmental protection and directives and upon approval follow up and supervise

their implementation;


implementation and undertake review of the project ESIA;

Undertake environmental. auditing of industries for the safe disposal and management of liquid and

toxic wastes;

Prepare appropriate standards to protect the environment that include soil, water and air as well as

the biological system in the City;


14


The KalitiWTP and its swear line is entirely located in Addis Ababa City Administration, Akaki-

Kaliti sub city of District 07.

2.4.1.3 The Oromia NRS Bureau of Land Administration & Environmental Protection

The “Oromia” BoLAEP has been re-established according to the “Oromia” Region Proclamation No

147/2009. The bureau is entitled with the power and a wide range of duties related to environmental

protection. The most relevant to the proposed project include the following:

Formulate policies strategies and standards pertinent to land and environmental protection;

Administer the land resource of the region and prepare land use plan;

Undertake cadastral survey register land holding and prepare land holding certificate;

In collaboration with concerned organs determine compensation to a person whose land holding has

been expropriated for development work;


implementation;

Undertake environmental auditing of industries for the safe disposal and management of liquid and

toxic wastes;

2.4.1.4 Addis Ababa Water and Sewerage Authority (AAWSA)

AAWSA was first established through the proclamation no. 68/1971 G.C as Addis Ababa water and

sewerage service Authority and it was reestablished through the proclamation no. 10/1995 G.C as

Addis Ababa Water & Sewerage Authority. It has the power and responsibility of supplying safe and

adequate water as well as management of wastewater (sewage) and sludge collection and disposal for

the Addis Ababa City. The proclamation articles 8 and 14 state that AAWSA shall have the power

and duties to ensure that any water sources are not polluted or contaminated, and rather work

towards their protection and conservation. The authority, however implements these activities in

collaboration with the concerned environment office, in this case the AAEPA and the Oromia

BoLAEP. AAWSA has a well-equipped laboratory to undertake sampling analysis and evaluation of

surface and ground water qualities.

2.5 World Bank Safeguard Policies

The World Bank environmental assessment (EA) requirements are based on a three-part

classification system such as Category A, Category B, and Category C. A project designated as

Category A requires a full environmental assessment followed by Independent Environmental

Review. Category B projects require a lesser level of environmental investigations. Category C

projects require no environmental analysis beyond that determination.

The planned Kaliti WTP falls under Category B Project […its potential adverse impacts on human

populations or environmentally important areas are less adverse than those of Category A projects]

since it is likely that the adverse environmental and social impacts can be controlled to acceptable

levels by designing and implementing appropriate mitigation measures. Hence, as per World Bank

requirements, this ESIA has been initiated.

The WB safeguard policies triggered by the project are given below in Table 2.1.


15


2.6 ESMF and RPF Requirements

The Government of the Federal Republic of Ethiopia has prepared two safeguard policy documents

that were agreed and disclosed as part of the borrower’s legal commitment to the project. These

policy documents are an Environmental and Social Management Framework (ESMF) dated April 13,

2007, and a Resettlement Policy Framework (RPF) dated May 4, 2007. These documents, in

conjunction with the guidance provided in the Project Implementation Manual (PIM), dated August

2007, need to be consulted directly during project implementation. The ESMF and RPF are briefly

described below and the ESIA study for the Kaliti WTP Project is carried out in accordance with the

ESMF and RPF requirements and the guidance provided in the PIM.

2.6.1 ESMF Requirements

The ESMF outlines an environmental and social screening process, which should be carried out in

parallel with other sub-project preparation activities such as technical, economic, and financial

analyses. The ESMF has been prepared because the Ethiopian guidelines do not make provisions for

the screening of small-scale sub-projects, which could have negative localized environmental and

social impacts that would require mitigation. Therefore, the provisions of OP 4.01 Environmental

Assessment for screening, assignment of environmental category, application of appropriate

environmental mitigation measures and/or preparation of separate Environmental Impact Assessment

(EIA) reports, review and clearance of screening results and/or separate EIA reports, consultations,

and monitoring are applied to the sub-projects.

The ESMF also includes requirements for the project implementers to incorporate measures for

protection of physical cultural resources in the project area. Such measures include chance find

procedures in the contractor bidding documents.

2.6.2 RPF Requirements

According to the World Bank’s OP 4.12, the development of a RPF is a requirement for projects that

may entail involuntary resettlement, impacts on assets, or loss of livelihoods. Any impact of the

Kaliti WTP Project on land and/or people (land acquisition, impact on assets, resettlement, and

livelihood restoration of affected people) will be addressed in compliance with the Constitution of

Ethiopia, with other Ethiopian regulations, and with the World Bank safeguard policy in involuntary

resettlement (OP 4.12).

Where gaps exist between Ethiopian laws and the Bank’s OP 4.12, the Kaliti WTP Project will

follow the requirements of the Bank’s policy. There is a gap between the existing Ethiopian laws and

the Bank’s OP 4.12 related to eligibility for compensation. According to the Bank’s OP 4.12, project

affected people are considered legitimate for resettlement assistance regardless of the legality of land

tenure. Whereas according to the Article 22 of the Ethiopian Regulations on Payment of

Compensation for Property Situated on Landholdings Expropriated for Public Purposes (Regulations

No. 135/2007), any person who claims for payment of compensation in accordance with the

Proclamation No. 455/2005 and the Regulations No. 135/2007 is required to produce proof of

legitimate possession of the expropriated landholding and ownership of the property entitling


16


compensation. Therefore, in relation to the Kaliti WTP Project, the RPF will follow the requirements

of OP 4.12.

It would be appropriate and possible for the Kaliti WTP Project to follow the agreed Resettlement

Policy Framework as it is expected to be in conformity with the Bank’s OP on Involuntary

Resettlement. The policies or principles provided in the RPF including design procedures to

minimize displacement, compensation principles and eligibility for compensation will be applied for

the Kaliti WTP Project. It is considered that the Kaliti WTP Project will fully implement the

resettlement and compensation procedures recommended in relevant sections of the final ESIA

report.


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3 PROJECT DESCRIPTION

3.1 Introduction

About 49 million m3 of wastewater is annually generated in the city of Addis Ababa. Wastewater is

mainly of domestic origin with 13.4% industrial. Most of this grey water is disposed into the rivers

and streams flowing through the city, like the Akaki River. Farmers have been producing vegetables

using Akaki River for the last 50 years and 1240 ha of land are being irrigated, mostly by gravity

using furrow or flood irrigation. Rural areas are supplying Addis with almost all crops, livestock,

horticulture and fruits, while urban agriculture is providing 61% of the vegetables consumed in

Addis (lettuce, Swiss chard, cabbage, spring onion, potato, beat root, etc.). The main concerns are

pollution of the water sources, the health hazard related to the use of untreated water for irrigation,

the environmental degradation and allocation of agricultural land to other purposes.

Addis Ababa Water and Sewerage Authority (AAWSA) is the only institution in Addis responsible

for all aspects of water supply of the city residences and sewerage control and wastewater treatment.

AAWSA has two water treatment plants in Addis Ababa, one of which is the Kaliti water treatment

plant which is located in southern Addis Ababa.

In connection with this AAWSA planned to rehabilitate and expand the Kaliti wastewater treatment

system. Following the plan, Kaliti Wastewater Treatment Plant Expansion and Rehabilitation as well

as the Expansion of Sewer Lines in the Kaliti Sewage Catchment was initiated in January 2012.

This new project is expected to play important role in enhancing the major wastewater treatment and

disposal problems the city is facing. As compared to the size of the city and population, this project

alone may not solve the problem.

Brief description of the project is given below. The technical details are included in the detailed

engineering design document which was conducted by Morrison Hershfield International Inc.in

association with ARMA Engineering PLC. The engineering design was carried out in 2012. In

evaluating the environmental impact of the sewer lines, a six-meter buffer zone is considered as

suggested by the client (AAWSA).

The location and detailed biophysical environment of the project area is given in Chapter 4. Much of

the sewer catchment is located in the inbuilt area of the city of Addis Ababa in southern and south

central Addis Ababa. The inbuilt area of Addis Ababa is found in the Akaki river basin, which is the

major tributary of the Awash River basin. The Entoto mountain range forms the northern watershed

boundary separating the Abay (Blue Nile) and Awash River basins. The volcanic mountains, Mount

Furi located southwest of the city and Mount Yerer located southeast of the city, are high massive

volcanic mountains rising to 2839 and 3100 m.a.s.l., respectively. These two high areas form the

western and eastern drainage divides of the Akaki River basin. To the south, most of the area is flat.

This flat land is characterized by high groundwater potential. The most important Akaki well field

which supplies water to the residences is located south of the treatment plant.

The project area (Kaliti sewer catchment)is dominantly confined in Bole, “Kirkos”, Akaki-Kaliti and

“Nefas-Silk-Lafto” sub-cities. The treatment plant is located in the Akaki-Kaliti sub-city, “Kebele”


18


7.

The Akaki river basin has high elevation differences in the north–south direction, which is the

general direction of the proposed sewer line. This characteristic has been taken in the design of the

new sewer line to function by gravity only. In most places, the new system follows the alignment of

existing sewer line.

The Kaliti sewer catchment consists of the old city, which is currently under redevelopment and with

new establishments in its periphery. Most of the industries are located in the Kaliti catchment

situated along the river/stream courses which are currently turned up as an open sewer channel. The

rivers and streams are polluted by waste coming from domestic areas, institutions and industry that is

discharged directly without any treatment. The construction of condominiums and the redevelopment

activities are demanding better sewage collection system with adequate capacity. Most of the

industries discharge their waste in to the streams. The existing WTP is also not functioning properly.

At some places, wastewater from broken sewer pipes is released into streams (Figure 3.1 B).

Currently, liquid waste from the drying beds at the Kaliti treatment plant is being released directly

into the Little Akaki river (see Figure- 3.1). Therefore, the proposed project is vital for improving the

current grave situations related to waste water treatment and management.

Figure 3.1 Plates showing grave situations of liquid waste management in the project area

3.2 Components of the Project

In this study, spatially three important areas are considered. These are:

i. The sewer lines (trunk lines)

ii. The wastewater treatment plant, and

iii. Downstream areas from the treatment plant

3.2.1 The Sewer Lines

In the context of the Engineering Report, three sewer trunk lines have been identified to be installed

on phase-by-phase basis. For ease of identification, the selected sewer lines are designated as

Western, Eastern, and Main/Southern Kaliti Catchment Sewer Trunks.

The Western Trunk extends from the ring road at Kaliti to north of “Lafto” bridge and services the

Western Kaliti Catchment.


19


Eastern Trunk extends from the ring road at Kaliti to Bole Bridge on African Avenue and services

the eastern Kaliti Catchment (“WolloSefer” and “Bole Medahnealem” areas and around “Nefas-

Silk”.

Main/Southern Trunk is the line that extends from the ring road at Kaliti to the KalitiWTP. This

trunk is proposed to twin the existing 800 and 700mm trunk mains.

The proposed sewer trunk mains will enable expansion of sewerage network within the catchment

and alleviate the present overflowing of sewage into streams, open channels and roads. The existing

sewer trunk has had a utility right-of-way, which at present is encroached on illegally over time by

squatter settlements. This will necessitate much effort to establish a new right-of-way and provide

sufficient space for construction and access for future operation and maintenance. The proposed

sewer lines (trunk lines) are expected to serve much the newly built southern and south-central Addis

Ababa. The total length of the sewer line is 18kms. The details are given in Table 3.1.

3.2.1.1 Western Trunk

The western trunk main runs parallel to the existing trunk main from the junction of the Eastern and

Main Trunk towards north along the Little Akaki River up to the existing manhole MH-KL. Then it

crosses the river to the west near “Lafto” condominium and continues along the bank of the little

Akaki River past the 600mm “Jemo” sewer line. In doing so, it passes through forested areas and

houses mostly made of mud and hollow block. This trunk main provides service for large part of the

Kaliti catchment including “Lafto”, Mekanisa, “Kirkos”, Mexico, “Merkato” western “Gulele”, and

“Ayer Tena” areas. The total length of the trunk proposed under this phase is 4,912m of which

3,140m is 1350mm diameter reinforced concrete pipe and the remaining 1200mm diameter

reinforced concrete pipe. Above-ground crossing structure using steel bridge is proposed at both

river crossings using pipe WM-54 and pipe WM-41.

3.2.1.2 Eastern Trunk

This section starts from “Karamara” Hotel(close to the Djibouti Embassy) and follows the right bank

of the lower reaches of the “Kebena” river and passes through complex slum and industrial areas in

“Bole Michael” and “WolloSefer” areas and crosses the ring road two times and finally joins the

western trunk at the Kaliti ring road overpass bridge. This route also crosses Debrezeit Road and the

new railway under construction close to the “Commet” Transport compound. Since this route has to

cross number of local ravines, there are areas where the excavation depth could reach up to 10m to

maintain gravity flow. The eastern trunk will affect many residential areas as compared to the

western trunk. Unlike the western trunk, however, it does not affect much farming areas (vegetable

gardens).

The eastern trunk is the longest and most complicated route of the three sewer trunks. As it is

reported,the initial surveying work has been done from the old “Karamara” hotel running parallel to

the existing sewer line up to the main trunk at MH T-1. However, this route has been changed to a

new route departing from the existing sewer line at MH-ES-144, nearby the existing manhole MH-

DF towards “Bulbula” Bridge passing east of “Saris-Addis Sefer” before it crosses the ring road near

“Abo” Church to join the main trunk at MH-T (at Kaliti ring road crossing).This change was made to


20


serve St. Joseph church area, and “Saris-Addis Sefer” and areas near and around the Agricultural

Engineering area. This Trunk serves the eastern part of the Kaliti catchment including areas up to

“Lagahar”, “Arada”, Paulos”, “Kechene” and “Addisu Gebeya”. The eastern trunk main has a total

length of 10,557m reinforced concrete pipes of which 7,724m is of 1200mm diameter and the

remaining 2,833m length is of 1050mm diameter.

Figure 3.2: Spot image showing the western trunk


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3.2.1.3 Southern Main Trunk

This main trunk starts from Kaliti ring road (overpass) and ends at the KalitiWTP. It is confined

within the Akaki-Kalitisub-city. It follows the side of existing gravel road. The southern trunk does

not affect many houses as compared to the other two trunk lines.

The main trunk is 1650mm in diameter and 1930 meters long, and is proposed to operate parallel to

the exiting 800 and 700mm mains to service the ultimate Kaliti catchment flow rate. The main trunk

receives wastewater from the two major trunks of Kaliti catchment; eastern and western trunks.

The existing trunk will be in operation during the construction of the new trunk. Therefore, special

consideration should be given in determining the alignment of the new line as crossing from one side

to the other is impossible once one side is selected. The other issue is the width of right-of-way

required to install the 1650mm trunk parallel to the 800mm. This section of the trunk was provided

with a right-of-way, but currently it is used as a road. In addition, private properties have encroached

to this right-of-way from both sides and the actual width of the right-of-way varies from 5 to 15m. It

is not practically possible to install the trunk main within the available space while using the right-of-

way as a road unless some arrangement is made beforehand. In view of this alternative access road

should be provided during the implementation of the project.

Manholes are placed at changes in diameter, gradient or direction, or at a predetermined section

length on straight run. For the trunk mains, manholes are spaced at an interval of 50 to 80m. Precast

reinforced concrete circular manholes have been designed for trunk mains. Different size of

manholes proposed for different diameters of the trunk are indicated below.

Table 3.1: Proposed Sewer Trunk and Manhole diameters

Sewer Trunk Diameter, mm Proposed Manhole Diameter, m

1050 1.8

1200 2.1

1350 2.4

1650 2.4

Table 3.2:Summary of proposed sewer trunks for Kaliti catchment.

Sewer Trunk Proposed pipe

size, mm

Length, m Service Area Remarks

Southern Kaliti Main Trunk (Kaliti

Ring Road to KalitiWTP)

1650 1,950 The whole Kaliti

Catchment area

Operate parallel to

the existing 700/800

mm trunk

Eastern Trunk (Kaliti Ring Road to

Bole Bridge)

1200 10,450 Eastern and Central-

Eastern Sub-

Catchments

Western Trunk (Dama Hotel to

Jemmo Trunk crossing)

1350 & 1200 950 & 1,900

respectively

Western and Central-

Western Sub-

Catchments

Existing siphons KA-

KB and LF-LG

would be removed

Kaliti Main Trunk (Kaliti Ring Road

to Dama Hotel), part of western trunk

1350 2,230 Western and Central-

Western Sub-

Catchments

Operate parallel to

the existing 700 mm

trunk


22


Figure 3.3: Spot image showing the eastern trunk


23


Figure 3.4: Spot image showing the southern trunk

3.2.1.4 Relation of Existing Sewer Line with the Proposed Sewer Line

Figure 3.5 shows the existing and proposed sewer lines. The existing treatment system is working

over capacity. In a number of places, broken sewer pipes exist. Manholes are stolen. The leaking

pipes release untreated liquid waste in the open ground and drain to nearby streams.

The proposed system is planned to serve mostly the newly developed areas and will help the existing


24


system to operate as designed by releasing the hydraulic load. The proposed sewer line is expected to

pass parallel to the existing system in many places. This will help to reduce the impact on

infrastructures. However, a number of houses are constructed even on the existing sewer lines at

some places. In most of the places, it is difficult to trace the position of the manholes.

In the southern trunk, the two systems pass parallel to each other until they join the treatment plant.

In the eastern trunk, the new system follows the existing system in the northern end and diverges to

the east to accommodate new inbuilt areas along the Akaki/Kebena River. In the western trunk, the

existing system extends far to the north and northwest. In much of the places, the two systems have

the same alignment and in few places, they cross each other.

Figure 3.5:Location map of the proposed trunk lines and existing sewer lines

3.2.2 Existing Wastewater Treatment Plant

3.2.2.1 General

Kaliti WTP is located in the southern part of Addis Ababa, the capital city of Ethiopia. The existing

Kaliti WTP is a lagoon treatment system built in the late 1970s and commissioned in 1983.

The Kaliti WTP has a design capacity of treating 7,500 m3/day of wastewater and 3,500 kg/day of

biochemical oxygen demand. This is equivalent to population of 50,000 P.E. At present, the

treatment plant is working with excessive hydraulic head.


25


Figure 3.6: Spot image of the Kaliti WTP

Sewage enters the existing Kaliti WTP via the gravity sanitary sewer piping system. Following

treatment in the lagoons, the treated effluent is discharged from the site through a natural drainage

channel to the river located to the west of the site. Some of the effluent is directed to small channels

and used to irrigate fields between the site and the river.

Trucked waste arrives at the plant and consists of a combination of latrine and septic tank waste. The

existing volume of trucked waste arriving to the site is approximately 5,600 m3

of waste per week.

This waste is simply dried in drying ponds that ring the western edge of the lagoons.

It is planned to keep the existing lagoons in operation during the construction of the upgrades. Due to

the increase in age and scale of the plant, most of the existing infrastructure will be replaced. The

existing office building is near the new primary clarifiers and may be impacted during construction

by the loss of the garden area that insulated the office from the working portion of the plant. The

building should not be impacted other than the aesthetic view by the loss of the vegetation.

The actual Kaliti site is large but most of the space is occupied by the existing facultative and

maturation ponds as well as the sludge drying ponds and beds. This means that space is at a premium

for upgrades to the wastewater treatment infrastructure.


26


Figure 3.7:Plates showing some features of the Kaliti WTP (A: Partial view of open canal and removed solid waste at

the entry point; B: One of the drying beds; C: Partial view of the stabilization ponds; D: Solid wastes at the treatment

plant)

3.2.2.2 Overview of the Wastewater Treatment Process

The treatment plant consists of inlet screens and grit chambers, two settling cambers, and two

parallel pond systems, and eight drying beds. The pond systems are rectangular and slant. Each line

of the pond consists of one facultative pond with a depth of 1–3m, one maturation pond with a depth

of 1m and two polishing ponds with a depth of 1m. The hydraulic retention time of the wastewater in

the stabilization ponds is approximately 30 days at maximum flow rate and the effluent from the

ponds flow by gravity and finally discharged to little Akaki river. Sludge lagoons and drying beds

were constructed in 1999 with treatment capacity of 110,000 m3/year of sludge.

The main components of the plant are:

i. Screening and De-gritting Channel

The treatment plant has a screening and de-gritting channel dimensioned from the beginning for

treating an effluent of 200,000 equivalent inhabitants. This piece of equipment is composed of two

canals. Each channel is equipped with an inclined screen (650) of a width of 2.5m leaving a free

space of 25mm between bars. The canals are designed to function in parallel and can be isolated by

means of coffer dams.

The length of each de-gritting channel is 10.5m. The outlet of each channel is equipped with a linear

weir (Eiffel tower type) and allows the maintenance of a constant de-gritting speed. The downstream


27


part of this apparatus includes a partially flume with a recording and totalizing flow meter, which is

installed in a small cabinet on the edge of the canal.

Figure 3.8: Kaliti WTP flow diagram. (Reproduced From AAWSA, 2002)

ii. Distribution Cell

The treatment plant has also a distribution cell that allows a partial or total feeding of all the stabilized

ponds. The volume of water allowed to re-circulate in each treatment path is measured by an

indicating, recording, and totalizing flow meter.

iii. Stabilization Pond

The treatment plant has two rows of paralleled biological treatment comprising 4 stabilization ponds

each whose global characteristics are shown in Table 3.3.

iv. Treated Water Recirculation Station

The treatment plant has 3 Archimedes screws, each capable of raising an incoming flow of 80l/s with

the following specification;

Diameter: 800mm

Speed: 51rpm

Motor power 7.5 and 10Hp

Max first phase recycling capacity: 13,824m3/d

During the second phase, the rotation speed is increased to 610rpm and the input flow to 105l/s.


28


Table 3.3: Characteristics of the biological wastewater treatment plant

v. Night Soil Treatment

The treatment plant consists of a set of night soils treatment work comprising:

a. Night soil digestion tanks

The night soil treatment has 4 digestion tanks with a unit capacity of 1130m3and a sludge

extraction system which uses a submersible mobile pump having a capacity of 20m3/h flow

rate at 15m total head.

b. Supernatant pumping station

This station is equipped with a submersible single vane impeller pump (with a capacity

of54m3/h flow rate of at 6.5m total head.

c. Drying beds

The night soil treatment has also a sludge drying area comprising 26 beds of 7.5m by 20.06m

area.

3.2.3 Proposed Technology for the New WTP

3.2.3.1 Treatment options evaluated during feasibility Study

The following treatment processes were evaluated in the feasibility study document:

Oxidation ditch

Trickling Filter

Upgrading the existing waste stabilization Lagoons

UASB with Trickling Filter

Moving Bed Bioreactor (MBBR)

Conventional Activated Sludge

Important factors considered to select the most appropriate technology or combinations of

technologies are: The design treatment capacity of 100,000 m

3/day


29


Space requirement for the proposed treatment capacity

Average BOD concentration of 740 mg/L which corresponds to the BOD load of 74,000 kg/day

Variation of the BOD load

Wastewater characteristics based on the data described in the feasibility study document indicates a

low strength wastewater with average values for BOD of 161 mg/L, Chemical Oxygen Demand

(COD) of 357 mg/L and Total Suspended Solids (TSS) of 495 mg/L. As also noted in the feasibility

study document, the values are too low considering the characteristics of municipal wastewater.

The top ranked three technologies were oxidation ditch, Trickling Filter, and upgrading of the

existing waste stabilization Lagoons. In terms of cost, upgrading of existing lagoon is the least

whereas the Oxidation ditch was the highest. Trickling Filter stood second with an estimated

construction cost of ETB 1,246,356,500.

Based on these, the feasibility study recommended Trickling Filter process combined with USAB as

suitable technology which can provide the required amount of BOD removal and accommodate the

expected fluctuations in BOD loads.

The major planned activities include:

Construction of a Trickling Filter treatment system as per the design;

Rehabilitate and/or modify the existing treatment infrastructure to increase life cycle

Cleaning of all of the existing facultative and maturation lagoons, dewater the collected bottom

sediment disposed the solid in a landfill,

Modify the lagoons for use as constructed wetlands for additional treatment enhancement;

Clean out the two northernmost sludge drying ponds and use this area for construction of the

thickeners and digesters;

Build new head works trains including screens with smaller openings;

Install system for collection and dispose of solids collected from the screens and grit to minimize

nuisances;

Provide trucked waste disposal site and treat trucked waste with the anaerobic digesters ;

Remove the toilet and carwash and rebuild near the head works so that their effluent flows can be

directly connected to the sewage treatment facilities;

Continue using sludge lagoons to dewater sludge;

Allow for future biogas recovery (by others) by making use of a standard rate anaerobic digester;

Abandon or demolish and remove structures that are no longer required or that do not have

sufficient capacity for the proposed treatment process;

Gas from anaerobic digesters will be flared until future methane capture systems are installed by

others;

3.2.3.2 Effluent Quality Criteria used to design the proposed treatment process

The wastewater characteristics used to design the proposed treatment processes is summarized in

Table 3.4.below.


30


Table 3.4: Wastewater Characteristics for Detailed Design

Parameter Unit Value

BOD mg/L 470

NH3 mg/L 45

TSS mg/L 600

Temperature °C 20

The feasibility study assumed that nutrient removal (i.e. nitrogen and phosphorus) is not a

requirement and that the proposed treatment plant will focus on BOD and TSS removal only. The

treated effluent is expected to be used for irrigation and when irrigation is not required, such as

during the rainy season, it is to be discharged into the river. The feasibility study also recommended

that possible applications of the treated effluent for industrial purposes would require further study.

To meet irrigation needs, the treated effluent treatment levels have been set in conjunction of various

factors such as protection of human health, protection of the environment (river and crops to be

irrigated), etc. within the constraints of the technologies selected.

Table 3.5: Treated Effluent Characteristics for Design

Parameter Unit Value

COD mg/L 100

BOD mg/L 35

TSS mg/L 35

Helminth eggs #eggs/L 11

E.coli E.coli/L 105

Wetlands have been designed to remove pathogens and particularly helminth eggs to meet

recommended treatment levels for irrigation usage. These wetlands will also remove nutrients

through plant uptake, which will assist in preventing algal blooms in the ponds and other water

bodies downstream of the plant.

The proposed treatment infrastructure layout is shown on Figure 1. This plan also shows a potential

location for future expansion of the same type of treatment process to 200,000m3/day. This would be

constructed in the future when the sewage collection system has been put in place to service the

population. The location for the future expansion would be where the current ponds exist and would

necessitate draining and filling in some of the proposed wetland area. The future expansion may

include newer and more efficient technology and the footprint may vary from the plan shown in

Figure 3.9.

The required level of treatment should be based on:

Whether wastewater is being discharged to surface water or to use for irrigation

National and local standards as reflected in permit requirements

Assimilative capacity of the receiving water for the load of contaminant being discharged after

treatment such as pathogens, BOD, COD, Nitrogen, phosphorus, heavy metals, and other inorganic

substances


31


Downstream use of the receiving water body (e.g. as a source of drinking water, recreation, irrigation,

or other)

Figure 3.9: Draft lay out of the treatment plant (taken from the detail design report)

The proposed series of treatment processes is very interesting and designed in suitable manner to

adapt to the specific situation. As noted from the feasibility study, providing a better wastewater

system will reduce, if not prevent diseases associated with poor sanitation; improved treatment will

permit reutilization of treated effluent for irrigation and improve the quality of river water; by-

products of the treatment processes can be harnessed to produce an alternative energy source and

fertilizer.

3.2.3.3 The Proposed Treatment Process Description

The Kaliti Wastewater Treatment expansion project comprises a centralized and integrated sewer

collection system and a single WTP. The new treatment plant will be constructed where the existing

plant structures are located. All the land is currently occupied and owned by AWSSA.

The WTP includes the following unit processes:

• Intake

• Fine screening

• Grit removal

• Primary clarifiers

• Up flow anaerobic sludge blanket (UASB) process

• Trickling filter (TF) process

• Secondary clarifiers


32


• Constructed wetland treatment

• Sludge Digesters

• Sludge drying

• Sludge disposal

The proposed wastewater treatment system is schematically presented in Figure 3.10.

Figure 3.10: The proposed wastewater treatment system

3.2.3.3.1 Intake structure

Two concrete chambers will be built upstream of the existing head works. The first splitter box will

be installed to collect flows from the existing 800mm pipe upstream of the headwork system. This

entrance chamber will be sized to accept 100,000m3/day. It has been estimated that the existing pipe

can supply a maximum of approximately half this flow. The remaining 50,000 m3/day, to meet

capacity, is expected to be supplied to the plant when the 1650 mm trunk main is built.


33


The future 1650 mm trunk main will be connected to another concrete chamber located to the west of

chamber. The flows received by second chamber will be sent to the first chamber until the combined

flows being treated at Kaliti reach a total of 100,000m3/day. The second chamber will be designed to

split flows between the first two trains and future trains to treat the additional flows.

A duplicate of the first Phase Head works structure will be constructed adjacent to the new structure

and will add an additional 100,000 m3/day capacity for a total of 200,000m

3/day. This component

will not be used until the second phase of the treatment process is designed and built. A stub pipe

will be constructed in the general direction of the future WTP expansion site to allow the future pipe

to be built without disturbing the headwork structure.

The design intent of the new pre-treatment system trains is for each train to be capable of handling

50,000m3/day. Once the first new train is in operation, the existing headwork stream will be

demolished and removed to make space for the second train.

Since the existing washroom near the thickeners will be demolished, a new bathroom has been

located and designed to be placed near the main guard house. Wastewater from the new bathroom

built near the guard house will be piped to the Train #1 screen chamber.

3.2.3.3.2 Primary treatment system

Bar screens: A grating of steel bars spaced about 2–4 cm on centers is placed at an angle to the flow

of sewage through an open channel. The raw influent first goes through a self-cleaning screen and

then into one end of a shallow and rather fast moving basin so that sand and gravel can settle out.

Often skimmers rotate around the surface of the basin to remove oils that may have been flushed into

the system. The screen removes coarse and floating solids from the sewage. The screen must be

cleaned regularly and the removed solids must be burned, ground and digested, or buried. Many

systems have a grinder known as a comminutor used either with or instead of a bar screen for

grinding large particles which might clog the pumps.

For the Kaliti upgrades, a coarse 2.5 cm opening bar screen will be installed which will be manually

cleaned. Following the coarse screen, a finer 1cm opening screen will be installed to remove smaller

detritus. The fine screen will be mechanically cleaned. Screenings will be discharged into hoppers

located above the channels where any water can drain back into the system.

Grit chamber: This operation removes gravel, sand, and fine mineral particles from raw wastewater,

in order to prevent deposits in channel and pipes, to protect, pumps and other machines against

abrasion, and in order to avoid problems in later treatment stages. It is a chamber in which the

velocity of waste flow is reduced to a point where the denser sand and other grit will settle out, but

the organic solids will remain in suspension. The settled material is buried or used for fill.

The screened wastewater will be conveyed in channels to the grit removal area. Grit will be removed

by mechanically induced vortex grit removal chambers. These chambers are designed to remove

greater than 80% of the silt, sand, and other inert material greater than 0.25 mm in size. The de-


34


gritted effluent continues to the bioreactor, while the collected grit is dewatered to approximately

75% solids content and stored for offsite disposal.

Rectangular horizontal flow grit channels will be constructed with each train including three

channels, each with the capacity to handle 25,000m3/d. The third channel is included for redundancy

to continue providing full flows during maintenance of the grit removal equipment. Grit collected in

the channels will be removed by a simple mechanical bucket conveyer system and can be mixed with

the screenings for disposal. As with the screenings, the grit will be collected into a container that

permits liquid to drain out but retains the solids. Surface area (A) of each channel is 23.1 m2, the

length of each channel (L) is 25 m; the depth of flow (D) is 0.69 m

Primary settling tanks (or basins): These are usually large tanks in which solids settle out of water

by gravity where the settleable solids are pumped away (as sludge), while oils float to the top and are

skimmed off. The velocity of the flow is reduced to about 0.005 m so that the suspended material

(organic settleable solids) will settle out. Removal of suspended solids ranges from 50–65%, and a

30–40% reduction of the five-day biochemical oxygen demand (BOD) can be expected.

In the case of the proposed project, four circular primary clarifiers are included in the design to

remove readily settleable solids and floating materials and therefore to reduce the suspended solids

content.

Flow will be equally distributed into the four clarifiers using a splitter box with sharp-crested weirs.

Each clarifier is designed to be at the same elevation, have the same surface area, side water depth

and effluent weir length and configuration. The 90° v-notch effluent weirs will allow for slight

adjustments in elevation to account for any momentum or turbulence which can force more flow into

one tank than another adjacent tank.

The primary clarifiers will be used to co-thicken secondary sludge to improve the solids content of

the combined sludge to around 4% instead of using thickeners. Thus, sludge thickeners have been

removed from the detailed design and the sludge will be sent directly to the digesters which will be

slightly larger in size. Secondary sludge will be pumped back to the primary clarifier splitter box on

a continuous basis as described the detailed design drawing set.

Since the clarifiers are uncovered, some additional freeboard has been used in the design to minimize

the wind effect from stirring the contents of the clarifier and re-suspending any particles. This

additional freeboard also provides safety for the operators as the outside wall is designed to be 1m

above the finished grade. Further details of the primary clarifier design can be found on the drawing

set. Assuming 4 clarifiers are required, each clarifier will have a surface area of 478 m2 and diameter

of 25 m.

The clarifiers are designed to remove the sludge and scum produced by the wastewater treatment.

Each clarifier will be equipped with a motor controlled traveling bridge with skimmers and spiral

plow scrapers. It is important to balance sufficient hydraulic detention time with preventing septic

conditions from occurring in the sludge blanket which could cause floating sludge. In a warm

climate, this is even more of a consideration than in colder climates therefore the clarifiers must

rapidly remove the sludge. The scrapers will scrape off the sludge that accumulates at the bottom of


35


the clarifier and convey it continuously to circular hoppers. The sludge will then be piped by gravity

to a collection chamber. The sludge blanket level will be controlled by cone valves located in the

collection chamber to regulate its depth. Scum consists of fats, oil and grease (FOG) and other

floating matter. Scum will be skimmed off the top of the wastewater by rotating skimmers into a

scum trough. It will then be piped to the same collection chamber as the sludge. From this chamber,

the sludge and scum will be sent by gravity to the anaerobic digesters for treatment. The quantity of

scum produced is estimated at 2% of the sludge produced.

3.2.3.3.3 Up Flow Anaerobic Sludge Blanket (UASB) Process

The up flow anaerobic sludge blanket (UASB) process is the most successful new anaerobic reactor

design for various industrial and municipal wastewaters. Compared to other anaerobic treatment

systems, it offers high COD removal efficiency at shorter retention times, small land area

requirement, low construction cost, simple operation and minimal pumping requirement. Its ability to

retain high biomass concentrations in the reactor is its key advantage.

Characteristic of a high rate system, the UASB system hinges on a sludge retention mechanism in

order to maintain contact between the wastewater and a high concentration of active bacterial mass.

The UASB reactor operates on the principles of an effective separation of the biogas, the liquid and

sludge, formation of an easily settleable anaerobic sludge, and even distribution of raw waste over

the bottom of the reactor.

An UASB reactor is basically a tank that has a sludge bed in which organic material dissolved in the

wastewater is degraded, and as a consequence of this digestion, biogas is produced. Influent

wastewater is introduced from the bottom of the reactor, through evenly distributed nozzles. The

sludge bed at the bottom of the reactor is the active bacterial mass that digests the organic pollutants

in the wastewater. Production of biogas that resulted from the anaerobic digestion process induces

mixing in the sludge blanket. At the upper part of the reactor, above the sludge bed, a blanket zone is

formed where some particles of biomass are suspended. This zone acts as a separation zone between

the water flowing up and the suspended biomass. One of the advantages of this kind of reactor is the

low sludge production. Dispersed sludge particles are separated from the liquid and return to the

digestion compartment at the phase separator, while the liquid leaves the reactor via the effluent line

and the gas through the top of the phase separator.

UASB reactors are attractive in tropical countries because they work better at mesophilic conditions.

They are widely used to treat wastewater with a high organic load; and the treatment of wastewaters

from the food industry is therefore a typical application.

The up-flow velocity and rising biogas bubbles are the principal factors causing mixing in the

reactor. Mixing in the sludge bed induces shear forces which are the key factor influencing the

formation, stability and structure of the anaerobic granules. Agitation is developed in sludge bed due

mostly to upward movement of biogas and particle-to-particle collision. Fine biogas bubbles may

adhere to the granule and cause the granule to rise.


36


Factors influencing performance of UASB are:

Wastewater pH

Temperature

Organic loading rate

Hydraulic retention time

Up flow velocity

pH: There are three principal bacteria involved in biogas production: bacteria responsible for

hydrolysis, acid-producing bacteria, and methane-producing bacteria. The acid producing bacteria

commonly tolerate a low pH, but their optimal pH range is from 5.0 to 6.0, on the other hand, most

methane-producing bacteria work well in a pH range of 6.7 to 7.4. If the reactor pH goes out of the

6.0 - 8.0 range, the activity of the methane-producing bacteria is reduced and this may negatively

influence the reactor performance. The bicarbonate produced by the methane-producing bacteria

normally controls the pH reduction caused by acid-producing bacteria.

Temperature - Methanogenic activity is seriously affected at temperatures below 30oC. In the range

from 37 to 55oC, sludge washout and an inefficient COD removal may occur. When the UASB

reactor temperature is above 55oC, the quality of the effluents is not as good as when the temperature

is under mesophilic conditions. Additional energy is then needed to heat the reactor and this

increases operation costs. The UASB reactor must operate under mesophilic conditions (30 to 35oC)

for successful results, but thermophilic conditions (i.e. 55oC) can result in more successful treatment

performance.

Organic Loading Rate (OLR): The OLR is the mass of organic matter loaded per day per cross-

section area of the reactor. The degree of starvation of microorganisms in biological systems is

dependent on the OLR. At a high OLR, microorganisms are subject to fast microbial growth (but

intoxication may occur with high quantities of organic matter), whereas at a low OLR,

microorganism starvation takes place.

A practical approach for the rapid start-up of a UASB reactor is to operate the system at a COD

reduction of 80%, which can be reached by manipulating the OLR. However, if the applied OLR is

too high, the biogas production rate may increase, and the resulting strong agitation can then lead to

washout of the inoculated sludge.

Hydraulic Retention Time and Up-Flow Velocity: The HRT is the average time that the influent

water remains inside the reactor, and the up-flow velocity is the liquid velocity crossing a transverse-

cross section of the UASB reactor; its units are m3m

-2h

-1.

The stagnant film around a granule can be reduced by increasing the up-flow liquid velocity. The

goal is to reduce the mass transfer resistance in the stagnant liquid around the granule in order to

increase the diffusion from the liquid phase into the microorganism growth. The up-flow water

velocity usually ranges between 0.1 and 1.4 m.h-1

in a UASB reactor.

In a reactor treating wastewater, the sludge bed and the blanket have dispersed particles between

which the wastewater passes and gas bubbles flow upwards. Therefore, even if the inlet fluid enters


37


the reactor with a relatively slow velocity, the flow distribution is not uniform due to the presence of

these granules and to the agitation produced by the gas bubbles. These phenomena determine the

residence time distribution (RTD).

Full-scale high rate anaerobic reactors have been built for the treatment of industrial effluents since

the 1970s throughout the world. An overwhelming majority about 72% of all plants of the existing

full-scale plants are based on the UASB or expanded granular sludge bed design concept developed

by Lettinga et al., 1980 in The Netherlands. Unfortunately, anaerobic biological treatment alone

cannot achieve the performance levels required for direct discharge in receiving streams. In

particular, the process has little effect on nitrogen removal. An aerobic polishing treatment is

generally necessary. It can be employed as a cost effective pretreatment ahead of aerobic treatment.

The marriage of these processes brings two advantages: Simple design technology and minimization

of sludge production.

In the case of Kaliti wastewater treatment expansion project, the AWSSA Project Office (the Client)

informed the EIA team that UASB reactors will be installed prior to the Trickling Filter. The

inclusion of UASB will have an added advantage in terms biogas production and improves the

overall effluent quality.

3.2.3.3.4 Trickling filter process

A trickling filter is a process that converts dissolved and colloidal waste material into solids.

Trickling filters flow into clarifiers or settling tanks where the solid separation takes place. The

trickling filter utilizes slime producing organisms to convert liquid wastes into solid form. Slime

growth is one of the main functions of trickling filters. The slime is also called “bio-mass” or

“microbial layer” and “sludge” when the solid is disposed. The trickling filter system employs the

following units:

A trickling filter is a fixed bed, biological filter that operates under (mostly) aerobic conditions. The

Trickling Filter is filled with a high specific surface-area material such as rocks, gravel, shredded

PVC bottles, or special pre-formed filter-material. A material with a specific surface area between 30

and 900m2/m

3 is desirable. The filter is usually 1–3 m deep but filters packed with lighter plastic

filling can be up to 12 m deep. Pre-settled wastewater, in this case the effluent from UASB ,is

‘trickled’ or sprayed over the filter. Organisms that grow in a thin bio-film over the surface of the

media oxidize the organic load in the wastewater to carbon dioxide and water while generating new

biomass.

The incoming wastewater is sprayed over the filter with the use of a rotating sprinkler. In this way,

the filter media goes through cycles of being dosed and exposed to air. However, oxygen is depleted

within the biomass and the inner layers may be anaerobic.

The ideal filter material has a high surface to volume ratio, is light, durable and allows air to

circulate. Whenever it is available, crushed rock or gravel is the cheapest option. The particles should

be uniform such that 95 per cent of the particles have a diameter between 7 and 10 cm. Both ends of


38


the filter are ventilated to allow oxygen to travel the length of the filter. A perforated slab that allows

the effluent and excess sludge to be collected supports the bottom of the filter.

The media become coated with a zoogloea film (a jelly-like growth of bacteria, fungi, algae, and

protozoa), and air circulates by convection currents through the bed. Most of the biological action

takes place in the upper 0.5 m of the bed. Depending on the rate of flow and other factors, the slime

will slough off the rocks at periodic intervals or continuously, whenever it becomes too thick to be

retained on the stones. A secondary settling basin is necessary to clarify the effluent from the

trickling filter. The overall reduction of BOD for a complete trickling filter system averages around

80–90%.

Trickling filters are classified on the basis of their hydraulic and organic loads as low or standard,

intermediate, high, or super high rate.

Standard rate trickling filters normally are designed for hydraulic ratings of 1 to 4 mgd/ acre (1.1

to 4.3 m3/m2 • d) and organic loadings of 5 to 25 lb BOD/ day/ 1,000 cu ft (0.08 to 0.41 kg/m3 • d).

These filters are normally 6 to 8 ft (1.8 to 2.4 m) deep and rectangular or circular in shape. They

usually are dosed intermittently by dosing tanks with automatic siphons or by periodic pumping. The

interval between dosing will vary with the rate of wastewater flow, but should be short enough to

prevent filter growths from becoming dry. Some recirculation may become necessary to achieve this.

During normal operation, a thick growth develops in the filter until a temperature change or the flow

through the filter causes a large portion to slough off.

Intermediate rate filters normally are designed to treat hydraulic loadings of 4.3 to 10.8 m3/m

2 • d

and organic loadings of 0.25 to 0.49 kg BOD/m3 • d including recirculation. In the past, there have

been some cases in which the organic loading in the intermediate range stimulated considerable

biological filter growth and the hydraulic loading was not sufficient to eliminate clogging of the

trickling filter medium. Other plants operating in this range have had few operational problems. In

some cases, intermediate rate filters actually are under loaded high rate filters.

High rate filters are normally designed for substantially higher loadings than are standard rate units.

A filter receiving a BOD loading between 0.41 to 4.88 kg/m3 • d. These filters usually are 0.9 to 2.4

m deep and circular in shape. They are designed to receive wastewater continuously. The high rate of

application is achieved by re-circulating wastewater that already has passed through the filter, and

the heavy flow of wastewater over the filter medium produces continuous rather than periodic

sloughing of the filter growths. Because the solids are not retained in the high rate filter as long as

they are in the standard rate unit, they are less stable and continue to exert BOD after they leave the

filter. The solids also are much lighter and more difficult to settle than those sloughed from a

standard rate filter

The high rate trickling filter was the option that was recommended in the feasibility study document

of the proposed Project as the best suited to the site and particularities of the wastewater to be treated

at Kaliti WTP. The media used will be engineered plastic media as that allows the filter to be taller

than rock filters which will reduce the footprint. The surface area of the engineered plastic media is


39


also greater, which allows for better treatment efficiency. Plastic media also helps to prevent

clogging since it has a high void ratio.

To avoid clogging of a trickling filter due to excessive growth of the biofilm, it is necessary to work

with the minimum hydraulic load. In most cases, wastewater is re-circulated from the filter effluent

to the top of the filter to dilute the strength of the incoming wastewater and to maintain enough

wetting to keep the biological slime layer moist. In this case, the trickling filter is being designed to

allow the wastewater to flow into the filter by gravity and without recirculation. This means that

more media is required to be purchased as a capital cost however pumps will not be required to re-

circulate the wastewater which will save ongoing operational costs.

It has been assumed that the trickling filter is required to reduce the BOD load down to 70 mg/L.

This value was obtained by evaluating what BOD removal could be achieved in the engineered

wetlands. This calculation is further detailed in feasibility study document.

Table 3.6: Trickling Filter Size

No. Parameter Dimension Remarks

1 Depth of TF (m) 6.1 m The reactor depth is high

2 Reactor volume 5,117 m3

3 Diameter 33m

4 Reactor Surface Area 839 m2×4

5 BOD loading 1.145 kg BOD/m3∙d

3.2.3.3.5 Secondary clarifier

The clarifiers are designed to remove the sludge and scum produced by the wastewater treatment.

Each clarifier will be equipped with a motor controlled traveling bridge with skimmers and spiral

plow scrapers. The scrapers will scrape off the sludge that accumulates at the bottom of the clarifier

and convey it continuously to circular hoppers. The sludge will be piped by gravity to a sludge lift

station. The sludge blanket level will be controlled by cone valves located in the lift station to

regulate its depth. From this lift station, the sludge will be pumped to the primary clarifiers for

thickening.

Scum consists of Fats, Oil and Grease (FOG) and other floating matter. The scum produced by the

secondary clarifiers will be skimmed off the top of the wastewater by a skimmer into a launder and

sent to a collection well. From the well, the scum will be pumped up to the digesters for final

treatment. The quantity of scum produced is estimated at 2% of the sludge quantities produced.

Since the clarifiers are uncovered, some additional freeboard has been planned in the design to

minimize the wind effect from stirring the contents of the clarifier and re-suspending any particles.

This additional freeboard also provides safety for the operators as the outside wall is designed to be

1m above the finished grade.


40


The supernatant from the secondary clarifier is the secondary effluent. Since its BOD level is still

high at approximately 70 mg/L, it will be sent to the engineered wetlands for further polishing and

storage. Sludge produced will be sent back to the primary clarifier where it will be co-thickened in

the primary clarifiers prior to being sent to the digesters for final treatment. The diameter and depth

of the proposed clarifiers is 27 m and 5m each, respectively.

Different combinations of processes are possible, depending on the trickling filter and UASB

processes used, the loading of individual units, and the point at which sludge or other recycled

streams are reintroduced to the main flow stream.

3.2.3.3.6 Constructed Wetland (Tertiary Treatment)

Constructed Wetland (CW) is a biological wastewater treatment technology designed to mimic

processes found in natural wetland ecosystems. The basic mechanism of organic matter degradation

in constructed wetlands is plant bacterial symbiotic reactions, in which gaseous oxygen

photosynthetically produced or taken up for respiration by the plant is used by aerobic and

facultative bacteria. Since the end of 1980, this system has been used widely in the world.

Constructed wetland is a shallow basin filled with some sort of filter material (substrate), usually

sand or gravel, and planted with vegetation tolerant of saturated conditions. Wastewater is introduced

into the basin and flows over the surface or through the substrate, and is discharged out of the basin

through a structure which controls the depth of the wastewater in the wetland.

A constructed wetland comprises of the following five major components:

• Basin

• Substrate

• Vegetation

• Liner

• Inlet/Outlet arrangement system.

The tertiary treatment process selected for the Kaliti WTP is to convert the existing facultative and

maturation ponds to engineered wetlands. As described in the feasibility study document, Free Water

Surface (FWS) wetlands are much simpler and less costly to adapt from an existing pond and

therefore the Kaliti ponds are planned to be converted to FWS wetlands. Wetlands are further

known to be effective in removing nutrients, metals and organics from wastewater. Given that the

WTP receives some industrial wastewater, the wetlands may assist in removing some industrial

pollutants which may remain in the wastewater otherwise and could inhibit plant growth in

agricultural fields or cause health problems.

The equal distribution and collection of wastewater is achieved by inlet and outlet arrangement

systems. A liner is used, if the protection of the groundwater is important.

Converting facultative and maturation ponds into wetlands involves cleaning out the sludge

accumulated in the facultative and maturation ponds, modifying existing inlet and outlet structures


41


and incorporating aquatic plants. It is proposed to use floating island systems that can be anchored to

the bottom of the ponds and drawn into shore for maintenance and troubleshooting. Floating islands

involve installing an artificial buoyant matrix that floats on the water surface upon which a variety of

macrophytes (woody plants) and grasses are planted. The surface of the floating island is porous

enough to allow plant roots to penetrate through into the water column, facilitating nitrogen and

phosphorus uptake through the roots and bacteria growth onto the roots. The vegetation also helps to

cool the surface of the water column and blocks sunlight which helps control algae growth. The

islands will be seeded with a variety of locally available plants.

The inlet, interconnection and outlet structures will be replaced to handle larger flows and to keep

the water level at between 0.6 and 0.9 m which is the optimal depth for floating aquatic plants to

thrive. The calculated surface area of the constructed wetland is 149,594 m2. The existing pond

surface area is approximately 208,313 m2. As shown in the calculation above, once converted to

wetlands, the existing area will be more than sufficient to polish flows of 74,626 m3/day from 70 mg

BOD/L to 35 mg BOD/L.

Advantages of constructed wetlands

• wetlands can be less expensive to build than other treatment options

• utilization of natural processes,

• simple construction (can be constructed with local materials),

• simple operation and maintenance,

• cost effectiveness (low construction and operation costs),

• process stability.

Limitations of constructed wetlands

• large area requirement

• Wetland treatment may be economical relative to other options only where land is available and

affordable.

• design criteria have yet to be developed for different types of wastewater and

In terms of the removal of pollutant such as pathogens, trace organics, nitrogen, and heavy metals,

CW has very distinct advantages. The removal mechanisms for nitrogen in constructed wetlands are

manifold and include volatilization, ammonification, nitrification/denitrification, and plant uptake

and matrix adsorption. The major removal mechanism in most of the constructed wetlands is

microbial nitrification/denitrification. Ammonia is oxidized to nitrate by nitrifying bacteria in aerobic

zones. Nitrates are converted to dinitrogen gas by denitrifying bacteria in anoxic and anaerobic

zones.

The process of metal removal in wetlands include sedimentation, filtration, adsorption,

complexation, precipitation, cation exchange, plant uptake and microbially-mediated reactions

especially oxidation. Adsorption involves the binding of metal ions to the plant or matrix surface,

whereas the presence of bacteria causes the precipitation of metal oxides and sulfides within the

wetland. Some wetland species have a well-established ability for direct uptake of metals.


42


Pathogens are removed in wetland during the passage of wastewater through the system mainly by

sedimentation, filtration and adsorption by biomass. Once these organisms are entrapped within the

system, their numbers decrease rapidly, mainly by the processes of natural die-off and predation.

3.2.3.3.7 Thickening and Stabilization of Sludge

All forms of sludge need to undergo treatment before being discharged into the natural ecosystem or

re-used. Stabilized sludge has an advantage in that photogenic organisms are greatly reduced,

therefore avoiding the problem of bad odor being produced during land disposal. The hazards due to

bacteria should not, however, be overlooked. In addition, the heavy metals, oil and grease, fibers, and

other trace substances of petrochemical origin are potential risks in using sludge for agriculture. In

general, the larger the quantity of sludge for disposal, the more it must be dewatered in order to keep

down the cost of disposal.

In the project, the primary clarifiers will be used for the purpose of sludge thickening as well. The

sludge which settles in the primary clarifiers is pumped to the sludge digesters where a temperature

of 30–35ºC is maintained. This is the optimum temperature for the anaerobic bacteria (bacteria that

live in an environment that does not contain oxygen). The usual length of digestion is 20–30 days but

can be slightly longer during cold months. Continual adding of raw sludge is necessary and only

well-digested sludge should be withdrawn, leaving some ripe sludge in the digester to acclimatize the

incoming raw sludge. Sludge is stabilized to reduce their pathogen content, eliminate offensive

odors, and reduce or eliminate the potential for putrefaction. Technologies used for sludge

stabilization include lime stabilization, heat treatment, anaerobic digestion, aerobic digestion and

composting. Among these methods, anaerobic digestion has great potential in terms of energy

generation and its performance is good. Two stage standard rate anaerobic digester was proposed for

the digestion of solids as well as the generation of biogas for energy recovery. Table 3.7 shows

description of the different

Table 3.7 Common anaerobic digesters

No. Type of digester Description

1 Standard rate This is a single-stage process in which digestion, sludge thickening and supernatant

formation take place simultaneously. The untreated sludge is added to the active

digestion zone, where it is heated by an external source. Mesophilic conditions are

maintained within the reactor. The resulting gas rises to the surface, carrying oils and

grease with it

2 Standard high-rate This process is a modification of the standard rate process. The solids loading is much

greater, and the sludge is mixed by gas recirculation, pumping or mechanical mixing

3 Two-stage This method features two tanks. The first serves for digestion and is fitted with heating

and mixing facilities, while the second is used for the storage and concentration of

digested sludge and for the formation of a clear supernatant

4 Separate This process, which is relatively new, involves the separate digestion of primary and

biological sludges.

5 Thermophilic Thermophilic digestion occurs between 120 and 135 ºF (49 and 57 ºC). This process is

characterized by a rapid digestion rate, increased bacterial destruction and improved

sludge dewatering. However, the process is characterized by higher energy

requirements, produces poorer quality supernatant and generates odors.

Design criteria for this system are as follows (for a maximum 100,000 m3/day Treatment Plant):


43


Average Day Retention Time: 25 Days

Digester Operating Temperature: 22 Degrees C

Average Day Solids Loading Rate: 3.37 kg Volatile Solids/m3/day

Digester Gas Production: 15 SCFM/lb Volatile Solids Reduction

Digester Gas Caloric Value: 600 Btu/SCFM

Volatile Solids Reduction: 36.7%

Total Solids Input: 55,792 kg/day (123,000 lb/day) @ 3.50%

Volatile Solids Input: 36,015 kg/day (79,400 lb/day) @ 2.25%

Total Solids Output: 42,820 kg/day (94,400 lb/day) @ 2.68%

Volatile Solids Output: 22,860 kg/day (50,400 lb/day) @ 1.43%

Tank diameter: 32.5 m

Water Depth: 8 m

Digested sludge will be drawn from the bottom of the second stage digester and conveyed to the

existing sludge drying ponds by means of progressive cavity pumps. Sample lines are available to

determine the approximate depth of the sludge blanket along the bottom of the digester. Clarified

liquid will be decanted primarily through an overflow system to a lift station where it will be sent

back to the trickling filters for treatment. Provisions have been made to permit the withdrawal of

clarified liquid at varying levels within the digester should it be required. Scum will be permitted to

degrade naturally over time.

A total of 42,820 kg/day of solid will be produced from the sludge digesters which will be

dewatered, stored on site and finally either disposed off-site in fills or will be used as fertilizer

depending on the quality of sludge. An estimated amount of 18, 007,500 L of methane can be

produced from the proposed sludge digesters.

3.2.3.3.8 Sludge treatment and disposal

Energy management is becoming an essential aspect of the design and operation of waste-water

treatment facilities. Some operations, such as aeration in biological treatment, consume large

quantities of energy, and consequently the selection of energy-efficient equipment and the design of

energy recovery schemes are assuming progressively greater importance.

The generated sludge is usually in the form of a liquid or semisolid. Sludge handling, treatment and

disposal are complex, owing to the offensive constituents present, which vary with the source of

waste-water and the treatment processes applied. Sludge is treated by means of a variety of processes

that can be used in various combinations. These involve thickening, conditioning, dewatering and

drying to remove moisture from sludge, while digestion, composting, incineration, wet-air oxidation

and vertical tube reactors are used to treat or stabilize the organic material in the sludge.

Options for sludge dewatering:

Use of chemicals

Press filtration

Belt filtration


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Vacuum filtration

Mechanical drying

Thermal drying for easier disposal: agriculture, soil improvement

Incineration in furnaces

Drying beds

Drying lagoons

In terms of best available technology, and based on current assessment/evaluation of various sludge

treatment and disposal options, thermal drying systems for advanced sludge treatment is the

preferred best technology for the following reasons:

Environmentally acceptable system for advanced sludge treatment because the entire process can be

contained within a closed circuit system. Emissions to atmosphere are minimized;

The end – product is clean, pasteurized, odorless and easy to handle and store. It is suitable as a soil

enriched; assuming the metal content is within the required limits.

Sludge quantity for ultimate disposal is considerably reduced.

The thermal and other mechanical processes are expensive in terms of initial investment and

operation and maintenance.

Sludge drying beds and lagoons are typically used to dewater digested sludge mainly due to low cost

for construction and operation. After drying, the sludge is either disposed of in a landfill or used as a

soil conditioner. The various types of drying beds in current use are described in Table 3.8.

Table 3.8 Types of Sludge Drying Beds and Lagoons

No. Sludge drying beds Description

1 Conventional sand

drying beds

Typical sand beds consist of a layer of coarse sand supported on a graded

gravel bed with perforated pipe under-drains. Sludge is placed on the bed and

allowed to dry. Drying occurs by evaporation and drainage. The sludge cake is

removed manually.

2 Paved drying beds These are similar to conventional beds in terms of their under-draining system.

Two types are commonly used: a drainage type and a decanting type. The

drainage type involves agitation to facilitate dewatering and uses a front-end

loader for sludge removal. The decanting type uses low-cost impermeable

paved beds that rely on supernatant decanting and mixing of the drying sludge

for enhanced evaporation.

3 Wedge-wire beds These consist of beds constructed from artificial media such as stainless steel

wedgewire or high-density polyurethane. The drainage process is controlled by

an outlet valve, enhancing the dewatering process.

4 Vacuum-assisted In this system, dewatering and drying is accelerated by the application of

vacuum to the underside of porous filter plates.

5 Drying lagoons The sludge is first placed within the basin and allowed to dry. The supernatant

is decanted from the surface and returned to the plant while the liquid is

allowed to evaporate. Mechanical equipment is then used to remove the sludge

cake.

Large size drying beds are feasible if they are equipped with traveling bridges allowing mechanical

recovery of dried sludge as well as spreading of liquid sludge across the whole surface area.


45


Depending on climatic conditions, drying times vary from three weeks to one month. Drying areas

generally include:

A first layer comprising a 20-cm layer of gravel. Drains are installed at the bottom of this support

A second filtering layer comprising 10 to 15cm layer of sand

Dewatering comprises a first drainage phase followed by ambient temperature drying. Dry sludge

content can reach 60% in the event of optimally sunny weather condition.

In the proposed project, the existing sludge drying lagoons will be rehabilitated as part of the

construction project as appropriate to accommodate the total amount of sludge generated by the new

process Sludge-drying lagoons are suitable for the treatment of digested sludge and consist of

shallow earthen basins enclosed by earthen dykes. The sludge is first placed within the basin and

allowed to dry. The supernatant is decanted from the surface and returned to the plant while the

liquid is allowed to evaporate. Mechanical equipment is then used to remove the sludge cake.

The dried sludge is a porous humus-like cake which can be used as a fertilizer base. In the proposed

project, the digested sludge will be disposed of in sanitary landfills. On the other hand, the beneficial

uses of sludge are attracting more attention nowadays. Treated and digested sludge may be used as a

soil amendment and conditioner. Sludge may also be treated chemically for use as landfill cover or

for landscaping or land reclamation projects. The digested sludge biomass can be used to generate

energy by employing appropriate waste to energy conversion process.

3.2.3.3.9 Biogas System

Typically, the biogas in UASB reactor treating domestic sewage is about 70–80% methane, and the

remainder is made up of a mixture of carbon dioxide, nitrogen, hydrogen, water vapor, and a small

fraction of hydrogen sulfide. Gases produced by the anaerobic digester system could be utilized at a

later date for the generation of power. Until that time, the biogas will be flared. Based on the

available information and the design criteria shown under the anaerobic digesters section, it is

expected that the digestion system will generate approximately on average 159 mscf/year at a

treatment plant capacity maximum of 100,000m3/day.

A single flare system will be capable to flare the quantities of biogas expected to be generated. The

flare system needs to be a minimum of 15 m away from the digesters. Actual quantities of biogas

generated may vary as a result of operation and the quality of sludge being produced by the

wastewater treatment plant.

The methane produced by fermentation can be stored in gas holders which compensate for

production fluctuations and facilitate delivery to the burners. These gas holders often consist of

flexible containers enclosed in structures, with a waste gas burner to complete the facility.

3.2.3.3.10 Use of Treated Wastewater and Stabilized Sludge in Agriculture

Treated wastewater effluent can be used for:

Irrigation


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Industrial

Recreation

Groundwater recharge

Potable water reuse

Discharge in to surface water

Treated wastewater effluent can be used for the irrigation of crops or landscaped areas. The main

consideration associated with this effluent application method is the quality of the treated water and

its suitability for plant growth. Some constituents in reclaimed water that are of particular

significance in terms of agricultural irrigation include elevated concentrations of dissolved solids,

toxic chemicals and nutrients. Another highly important consideration is public health and safety

hazards resulting from the potential presence of bacterial pathogens, intestinal parasites, protozoa

and viruses. Concerns vary with the intended irrigation use and the degree of human contact.

Potential constraints associated with the use of reclaimed wastewater for irrigation include the

marketability of crops and public acceptance, surface and groundwater pollution in the absence of

adequate management, and high user costs, notably the cost of pumping effluent to irrigated land.

Irrigation with treated water requires measures to prevent public health, salinity and toxicity hazards.

Effluent of a high biological quality is necessary for irrigation of certain crops, particularly

vegetables and other produce that may be eaten raw. A low quality is acceptable for crops that are

processed or where there is no direct exposure to the public. The most important criteria are those

that safeguard the health of farmers, farm workers, produce handlers and consumers. The primary

indicator of health risks are the level of fecal e-coli forms and helminth eggs for which the World

Health Organization has set the guidelines.

Dissolved salts and toxic ions present in treated effluent arrest plant growth, crop yield and produce

quality. There is wide range in the tolerance of specific crops to salinity and toxicity and carefully

selection allows a greater use of wastewater for irrigation, thus preserving freshwater. Effluent

quality of the Kaliti WTP will meet the FAO Guideline for using treated wastewater for irrigation

(Annex 4).

Reclaimed water is ideal for industries using processes that do not require water of potable quality.

Industrial uses of reclaimed water include evaporative cooling water, boiler-feed water, process

water, and irrigation and maintenance of the grounds and landscape around the plant. Each type of

reuse is associated with a number of constraints on its applicability; the use of reclaimed water in

cooling towers, for example, creates problems of scaling, corrosion, biological growth, fouling and

foaming. These problems are also encountered when fresh water is used, but less frequently.

Reclaimed water used as boiler feed water must be softened and de-mineralized, while process water

quality is dependent on the requirements of the manufacturing process involved.

Reclaimed water is widely used for recreational purposes, including landscape maintenance,

aesthetic impoundments, and recreational lakes for swimming, fishing, and boating, ornamental

fountains, and fish farming. The required treatment level for reclaimed water is dictated by the


47


intended use: the greater the potential for human contact, the higher the treatment level required. For

example, non-restricted recreational water use requires the treatment of secondary effluent by

coagulation, filtration, and disinfection to achieve a total coliform count of fewer than 3 per 100

milliliters.

Groundwater recharge using reclaimed wastewater serves to mitigate water table decline, protect

groundwater in coastal aquifers against salt-water intrusion, and store reclaimed water for future use.

Groundwater recharge methods include surface spreading in basins and by direct injection into

aquifers.

Surface spreading utilizes flooding, ridge and furrow, constructed wetlands, and infiltration basins.

This application method improves the quality of the reclaimed water considerably as it percolates

successively through soil, unsaturated zone and aquifer. Direct injection involves the pumping of

reclaimed water directly into an aquifer. Drawbacks of this method include high effluent treatment

cost and the high cost of the necessary injecting facilities. The major disadvantage of groundwater

recharge using reclaimed water is the increased risk of groundwater contamination.

The issue of the use of reclaimed water for drinking purposes has been approached with extreme

caution because of public rejection and because of health, safety and aesthetic concerns. Although

extensive research is being conducted in this field, many constraints remain, notably the

determination of appropriate quality criteria for such water. At present, the option of direct potable

use of reclaimed municipal waste-water is limited to extreme situations. if not reused, is disposed of

either on land or into water bodies.

Discharge into water bodies is the most common disposal practice. It takes advantage of the self-

purification capacity of natural waters to further treat the effluent. However, waste-water effluent

discharge must be based on sound engineering practice if the receiving environment is not to be

adversely affected. Excessive quantities of organic material may cause rapid bacterial growth and

depletion of the dissolved oxygen resources of the water body. In addition, changes in pH or

concentrations of some organic and inorganic compounds may be toxic to particular life forms.

Accordingly, outfall structures must be designed for adequate dispersal of the effluent in the

receiving waters in order to avoid localized pollution. Depending on the characteristics of the

receiving waters, many factors are considered for proper mixing and dispersal of effluent. These

factors include flow velocity, depth stratification due to salinity and temperature, shape, reversal of

current and wind circulation. The temperature and salinity of the effluent should also be taken into

consideration. The disposal area should be downstream from any location where water is to be

withdrawn for human consumption.

Wastewater effluent discharge into rivers should be such as to ensure rapid vertical mixing of the

effluent over the full river depth and avoid foaming problems. This can be achieved by using a

multiport diffuser that extends across the width of the river. A diffuser is a structure that discharges

the effluent through a series of holes or ports along a pipe extending into the river.


48


In conclusion, the treated wastewater effluents from the Kaliti wastewater treatment system can be

used for all purposes except potable use and recreation. It is important to note that the best suitable

option needs to be established through further evaluation. Considering the tremendous demand for

agricultural activities, it is proposed by the project to use it for irrigation.

3.3 Downstream Areas from the Treatment Plant

The wide compound of the treatment plant is not fenced and there is no new settlements within the

compound. There is no new proposed settlement site in the area. The only large-scale structures

constructed within the compound are the high tension power line towers. Within the treatment plant

site, one can see many birds and animals such as hyenas, monkeys and antelopes. The highly

vegetated compound and the downstream riparian vegetation of the Little Akaki river course harbor a

number of animals. Three important zones can be identified downstream of the treatment plant

(Figure 3.11).

3.3.1 Farming Areas

West of the treatment plant, the area is covered with vegetable gardens and grass land with few

houses (only three houses). The local community is growing vegetables (mainly cabbage) in these

areas. Even within the treatment plant compound, some areas are being used for growing vegetables.

In the dry season, the effluent is diverted in open ditches for local irrigation. The Little Akaki River

seems to be more polluted than the water being released from the treatment plant. Interviewed people

in downstream areas stated that the river water is much polluted and they are not interested to use it

even for irrigation compared with the effluents from the treatment plant.

3.3.2 Settlement Area

Much of the open grounds which were considered as command area in the irrigation feasibility

document is currently having many houses. Most of “Kebele” 7 is confined in the downstream area.

Along the right bank of the Little Akaki River there are many mud houses which appear to be not

having legal permissions. The vegetable gardens along the course of the river are owned by the

residents of these areas.

3.3.3 Riparian Vegetation

The course of the little Akaki River is highly vegetated. This becomes important habitat for birds and

animals. Some of the trees (eucalyptus) are owned by local residents. Figure 3.11(C) shows partial

view of the riparian vegetation. The type of vegetation in this area is listed in Chapter 4 that outlines

the biological environment.


49


Figure 3.11: Some features of downstream areas from the treatment plant (A): vegetable gardens grown on the sold

sludge being disposed from the drying beds; (B): Grassland along the course of the Little Akaki river; (C): Riparian

vegetation where many birds and animals’ reside along the Little Akaki river; (D): Inbuilt areas (“Kebele” 7) which

was considered as command area for irrigation in the irrigation feasibility study document


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4 ENVIRONMENT AND SOCIAL BASELINE CONDITIONS

4.1 The Physical Environment

4.1.1 Topography and Drainage

The project area is located in the central and southern part of the Akaki river basin. The Akaki river

basin is an extensive drainage system located at the eastern edge of the Western Ethiopian plateau

that slowly descends to the central Main Ethiopian Rift. The city of Addis Ababa is situated in the

northern and central part of the basin (Figure 4.1). The basin has an elevation drop of around 1000 m

within 20 km lateral distance all the way from the Entoto ridge in the north to the plains of Akaki

area to the south where the Akaki well field is located. The Kaliti WTP is located in the southern part

of the drainage basin.

Figure 4.1: Digital Elevation Model and simplified drainage map of the

Akaki river basin with city boundary

The treatment plant is located at an elevation of around 2200 m.a.s.l. The treated wastewater is

expected to be released into the Little Akaki River which is the main tributary of the Big Akaki river

that inturn joins the Awash River far to the south.

Within the Akaki river basin, there are a number of perennial rivers. The most important ones are

Big Akaki, Little Akaki and Kebena. Much of the new sewer line passes within the Little Akaki,

Kebena and the lower reaches of Kebena and Big Akaki river catchments (Figure 4.2). The Kaliti

sewer catchment comprises parts of “Kirkos”, “Nefas-Silk Lafto” and Akaki-Kaliti sub cities.


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Figure 4.2: Drainage map showing the Little Akaki and Big Akaki rivercatchments with project area (red window)

The river catchment has high elevation differences as compared to the drainage catchment. Figure

4.3 shows the digital elevation model and North-South topographic section. The Akaki River

catchment has an elevation range of 2040 to 3,200m above sea level (Topographic Map of Scale

1:50,000, EMA, 1973). Ridges/volcanic centers and mountain ranges bound much of the basin

watershed boundaries.

There are many rivers/streams draining in the basin. The most important ones are Big Akaki, Little

Akaki and Kebena. The latter two drain much of central Addis Ababa area. The main recharge area

to these rivers is the Entoto ridge.

Most of the watershed divide is characterized by large volcanic mountains/ridges. The most

important elevated peaks are Entoto Mountain Range (pick elevation 3200 m.a.s.l), Mt. Bereh

3,228m m.a.s.l, Wechecha range (3,391m a.s.l), Mt. Furi (2839m.a.s.l.) and Mt. Yerer (3100m a.s.l.).

The lowest elevation is Aba Samuel dam to the south (2060m a.s.l.).

The Kaliti wastewater catchment is confined mainly in the Little Akaki and lower reaches of the Big

Akaki river catchments. The wastewater collection system flows by gravity.

4.1.2 Land use / land cover

Although very much diverse, the general land use/cover pattern of the Akaki river basin can be

broadly classified into four groups: forest, urban (inbuilt) area, agricultural or open areas and water

bodies ( BCEOM- Seureca, 2000). A more detailed land use map of Addis Ababa city is shown in

Figure 4.4.


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Figure 4.3: Simplified digital elevation model with N-S sections of the Akaki river basin

In the northern part of the basin along the Entoto Ridge, the land is covered with forest, dominantly

eucalyptus trees and the top of the mountain range is relatively flat that facilitates infiltration of

precipitation into the ground. As the slope gets steeper towards the city, a relatively higher runoff

coefficient is expected. Along the foot of the Entoto ridge there are small waterfalls.

Much of the central part of the basin is in built area (houses, roads and large establishments such as

factories). The Addis Ababa city is characterized by paved surfaces /built up areas that cause very

low infiltration. Along the course of the main streams, urban agriculture is common. The two main

trunks of the sewer line pass through small shabby houses and in places through vegetable gardens

and eucalyptus trees. At two places it crosses highly vegetated woodland in the western trunk Behere

Tsige Public Park and “Lafto Mebrat Hail” forested area).Figure 4.5 shows some typical vegetated

land cover types in the project area.

The sewer lines pass through wide compounds of government institutions. The major ones are

Defense Construction, “Ersha Sebel”, “Commet Transport”, Spices Extraction Factory and Behere

Tsige Public Park. Along the proposed sewer lines there are no churches, cemeteries, statues and

related sensitive areas except the Saudi Arabian Embassy and a Mosque under construction (both in

“Wollo Sefer” areas) that would be affected by the new project. The plate in Figure 4.6 shows partial

view of these structures.


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Figure 4.4: Simplified land use/cover map of Addis Ababa area

Figure 4.5: Typical vegetated land cover types in the project area (A: Woodland; B: Riparian vegetation with

settlement; C: Vegetable gardens(D: Grass and farm plots in the treatment plant area).


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Figure 4.6: The two sensitive areas that are going to be affected bythe sewer lines (A: Mosque and B: The Saudi

Arabian Embassy)

4.1.3 Climate

In the Akaki River basin there are at least five meteorological stations. The stations are located at

Addis Ababa Observatory, Addis Ababa Bole, “Akaki Mission”, “Entoto” and “Sendafa” areas.

Table 4.1 shows the summary of the long-term average meteorological data obtained from stations in

Addis Abba area.


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The Akaki river basin has humid to sub-humid climate. Based on rainfall, the climate of the area can

be categorized into two broad seasons. The dry season that extends from October to May and the wet

season that lasts from June to September. The main rainy season is from June to September.

Precipitation was recorded in the catchment since 1900 at Addis Ababa Observatory except between

1941 and 1945. The mean annual rainfall at Addis Ababa observatory for the period 1980 – 2005 is

about 1187.4 mm. The minimum arithmetic mean monthly rainfall amount in the basin was recorded

in December (6 mm) and the maximum value was for the month of August (279 mm). Most stations

in elevated areas recorded higher values. The high rainfall of the region flushes solid and liquid

wastes from inbuilt areas during the wet seasons. Many of the rivers in Addis Ababa area are highly

polluted due to the release of solid and liquid waste that is being flushed by surface runoff and direct

release from industries and households.

Table 4.1:Summary of mean monthly long-term meteorological data of Addis Ababa area.

Parameter Station

Months

Jan. Feb. Mar. Apr. May June July Aug. Sep. Oct. Nov. Dec. Total

Rainfall, mm Intoto(1989-2004) 15.6 38.3 61 87.2 43.2 102.2 265.3 317.1 138.4 27.2 9.9 9.8 1115.2

Sendafa(1991-2004) 20.8 18.5 47.7 52.4 43.7 118.6 328.8 308 106.1 49.1 3.6 3.8 1101.1

Akaki (1975-2004) 14.1 29.8 76.7 86.1 68.5 115.2 255.4 258.5 118.8 25.1 3.6 3.2 1055

AA Bole(1980-2004) 11.8 33.6 68 93 71.1 122.5 235.9 240.3 133.5 30.9 3.2 4.9 1048.8

AA Obs(1980-2005) 14.2 39.1 68.9 91.5 83.7 136.2 262.4 272.9 168.7 34.9 5.8 9.2 1187.4

Mean 15 32 64.4 82 62 119 270 279 133 33 5 6 1100.5

Temp.0c Entoto (1989-2004) 19.1 19.7 19.9 19.4 20.1 17 15.9 15.9 15.8 16.8 18.6 17.5 215.9

AA Obs (1980-2005) 23.9 24.9 25 24.5 25.1 23.4 21 20.9 21.7 22.7 23.1 23.2 279.6

AA Bole(1980-2004) 23.8 23.8 26.3 24.8 25.3 23.5 21.2 21.1 21.8 22.9 23.2 23.2 280.8

Akaki ( 1997-2004) 26.3 27.3 27.4 27.3 28 26.3 24.3 23.8 25.3 25.8 25.9 25.9 313.6

Mean 23.3 24 24.7 24 24.6 15.9 20.6 20.4 21.2 22.1 22.7 22.5 265.8

Pan Evap. Mm AA Bole(1987-2004) 186.1 190 190.8 177.4 202 106.2 62.3 60.6 99.5 287 189 171 1921.9

AA Obs (1992-2004) 131.7 141 145 117.6 138.3 84.2 52.7 50.2 73 121 137 127 1319.4

Mean 158.9 166 167.9 147.5 170.2 95.2 57.5 55.4 86.3 204 163 149 1620.7

Sunshine Hr AA Obs (1964-1993) 8.6 8.1 7.2 6.5 6.8 5.1 3 3.5 5 8.1 9 9.1 80

Mean 8.6 8.1 7.2 6.5 6.8 5.1 3 3.5 5 8.1 9 9.1 80

Wind speed km/hr AA Obs (1982-2004) 0.7 0.7 0.8 0.8 0.7 0.5 0.4 0.3 0.5 0.8 0.8 0.7 7.7

Mean 0.7 0.7 0.8 0.8 0.7 0.5 0.4 0.3 0.5 0.8 0.8 0.7 7.7

R. H in% AA Obs (1979-2004) 41.7 40.6 43.3 46.9 42.7 53.8 65.8 67.1 56.5 40.4 35.1 33.6 567.7

AA Bole(1964-2004) 55.9 55.1 56.2 63.4 59.9 73.9 86.2 86.3 81.9 61.3 53.8 55.9 790

Mean 48.8 47.9 49.8 55.1 51.3 63.9 76 76.7 69.2 50.9 44.5 44.8 678.8

Source: National Meteorological Services Agency

The highest and lowest mean maximum temperature over the record periods (Table 4.1) is 250C in

dry season (March) and 200C in wet season (August), while the variation of mean monthly

temperature values fall in the range of 70c (in the month of December) to 12

0C (in the month of

March). The daily variation in temperature in the area is more pronounced than the annual variation.

The calculated mean annual long-term mean temperature is around 16.30C (Solomon Tale, 2000).


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The highest relative humidity was 78% recorded in the months of July and August, and the lowest

was 53% recorded in the month of December (from 1964 – 1989). The lowest sunshine hour, 3 hours

per day was recorded in July and the highest 9.5 hours per day, which was recorded in December for

the years (1965 –1985). Likewise, maximum wind speed of 1.2m/sec and minimum value of 0.5m/se

were recorded for the months of October and August, respectively.

4.1.4 Hydrology

As the rainfall is well above 1000 mm annually in elevated areas, most streams are perennial due to

sustained recharge from fractured volcanic rocks. The two most important rivers in the basin, Big

Akaki and Little Akaka are gauged. The long term average discharges of these rivers indicate that the

maximum discharge occurs during the months of July and August and the Minimum in February and

March.

The hydrographs of these two rivers are shown below (Figure 4.7). The hydrograph of Big Akaki

River was constructed from long-term (1981-2003) mean monthly discharge. For Little Akaki River,

it was made from gauged mean discharge of the periods 1991-2003.

Figure 4.7: Hydrograph of Big Akaki and Little Akaki rivers established based on long-term average monthly

discharge (Source: Ministry of Water and Energy)

4.1.5 Geology

4.1.5.1 General

The Akaki river basin has very complex geology. The area is characterized by tertiary volcanic rocks

disrupted by many regional faults. As it is located at the edge of the rift valley, it is not also

seismically stable. Much of Addis Ababa is located in seismic zone 2, which can likely be affected

by earthquakes.

Much of central Ethiopia, where the basin is located is covered by volcanic rocks of different ages

and types. One can categorize these volcanic rocks based on various criteria such as age (Tertiary

and Quaternary volcanics), and taking rift formation as a reference (pre- rift & post- rift volcanics).

The volcanic rocks of Ethiopia can also be described as the Trap series volcanics and Aden Series


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volcanics, which is the same as to say post rift volcanics. The trap series represent the oldest volcanic

rocks in the country compared to Aden series volcanics. The trap series forms the northwest and

southeast plateau, reaching its maximum development in central Ethiopia attaining a thickness of up

to 3 km, (Mengesha et al., 1996).

The trap series predates the rift faulting and usually occupies great height of the Ethiopian Plateau,

whereas the Aden volcanic series are associated with well – preserved volcanic cones or lava flows,

Mohr (1971). Since the Akaki River basin lies between the plateau and the rift floor (Zennettin and

Justin – Visentine, 1974), the geological history of the area is an integral part of the evolution

/development of the Ethiopian plateau and the Rift system. The study area represents both the

highland and the rift escarpment which descends to the south towards the ill-defined rift floor.

4.1.5.2 Lithology

As outlined in the works of BCEOM – seureca (2000) the following stratigraphic units can be

identified in the basin from the oldest to the youngest.

1. Alaji series (Lower Miocene)

This unit covers the Entoto Mountain and extends to the north beyond the Akaki basin. It comprises

of basalts associated with rhyolites, trachytes, ignimbrites, tuffs and agglomerates. Earlier works

further subdivided this series into Alaji Rhyolites and Entotosilicics.

2. Addis Ababa Basalts

They overlie Entoto silicics and outcrops mainly occur in the Entoto Mountain, central Addis Ababa,

along Akaki River course (south) in the vicinity of Laga Dadi dam to the north of Lake Gefersa and

southern part of the city. Their composition can be porphyritic olivine basalt, porphyritic feldspar

basalt & aphanitic basalts. Individual flows are usually easily observed & paleosols & coraceous

horizons are found at the bottom of flows in many places (Kebede Tsehayu and Taddese

Hailemariam, 1990).

According to Solomon Tale (2000), Olivine porphyritic basalt outcrop in the central part of the town

(“Merkato”, “Teklehaymanot” and “Sidist kilo”) and the distribution of plagioclase porphyritic basalt

is little northwards around “Sidist kilo”, General Wingate school and French Embassy. According to

Morton (1974) and Vernier (1985), the thickness of the olivine porphyritic basalt varies from 1m or

less in the foothills of Entoto, Lideta Air Field and “Filwuha” to greater than 130 meters at

“Kechene” stream.

The basalt flows are inter-bedded with welded glassy and fiamme ignimbrite outcrops in the areas of

“Filwuha”, “Ginfle” and Lideta Air Field. At many outcrops it is overlain by aphanitic basalt flow

and underlain by olivine porphyritic basalt flow (Anteneh Girma, 1994).

3. Younger Volcanics

These groups of volcanics can broadly be classified in to Nazareth Group and Bofa Basalts.

According to Hailesellasie Girmay and Getaneh Assefa (1989), the Nazareth Group rocks out crop


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dominantly to the South of Filwuha Fault and extend towards Nazareth. Bofa basalts are found

southward from Akaki River, southeastern part of Addis Ababa

4. Nazareth Group

Aphanitic basalt, welded tuffs, ignimbrites, trachytes and rhyolites make up this group of younger

volcanics. Aphanitic basalt flows cover the southern portion of Addis Ababa, south of Asmara Road,

especially the areas of Bole and Lideta. The flows show vertical and curved columnar jointing

together with sub-horizontal sheet jointing (Anteneh Girma, 1994). According to BCEOM – seureca

(2000), trachy – basalt out crops are found around “Repi” area and General Wingate School and

associated with undifferentiated volcanics. It is underlain by the plagioclase and olivine porphyritic

basalt, and overlain by the younger ignimbrite from which it is separated by tuffs and agglomerates

(Hailesellassie Girmay, 1985).

Figure 4.8: Simplified geological map of the study area (Source: Dereje Negusa, 1990)

An ignimbrite sheet (upper Welded tuff) out crop occurs in the northeast of Addis Ababa at the base

of “Entoto” Mountain and Laga Dadi areas. This formation is gray colored, vertically and

horizontally jointed (Hailesellasie Girmay and Getaneh Assefa, 1989). It is underlain by aphanitic

basalt and overlain by young olivine basalts (Hailesellasie Girmay, 1985).

According to Anteneh Girma (1994), this group is underlain by tuff deposits and overlain by olivine

porphyritic basalt flow to southeast of Addis Ababa. From a sample taken from Addis Ababa (near

Asmara Road).


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Trachytic flow covers extensive areas in the west and southwest part of the catchment, from Mt. Furi

Hana Mariam, Tulu Iyoo to Repi and Wechecha Range. The trachyte flow is underlain by tuff and

overlain by alternating flows of plagioclase basalt and rhyolite at “Repi” (Anteneh Girma, 1994).

Rhyolite flows belonging to this group outcrop at the top and southern flanks of Mt. Yerer. The

exposed thickness of the lava sequence is about 500m (Anteneh Girma, 1994).

5. Bofa Basalts

This unit comprises of olivine porphyritic basalt, scoria, vesicular and scoriaceous basalt, and trachy

- basalt lava flows. They extend in to the south from Akaki River and the unit is as thick as 10 meters

(AntenehGirma, 1994). They appear to have upper thick basalt of 20 - 40m over the Akaki well field

but thinner to absent in other places. They have well preserved shape of cones and marls.

6. Lacustrine Deposits, alluvial & Residual soils

These are quaternary to recent deposits. Lacustrine soils occur around Bole, Lideta, Mekanisa,

Between Abba Samuel Lake and Little Akaki River. The thickness of this deposit varies between 5m

to 50m.

Alluvial deposits are found in some places along small and Big Akaki Rivers, especially south and

southwest of the capital city. Thick alluvial deposit occurs in the area between Akaki town and Abba

Samuel Lake. Some deposits occur along the Kebena River, north - west of Bole area. Soils, which

are developed in-situ by the decomposition of rocks are located in the central, southeast, northeast,

Gullele and Kolfe areas.

4.1.5.3 Geological Structures

It is in accordance with the location of the catchment at the shoulder of the Main Ethiopian Rift that

the project area has been subjected to the rift tectonics, which is manifested by a number of major

and minor fault systems. As it can be seen from the map of the geological structures of area compiled

by BCEOM – Seureca (2000) the general trend of most of these faults follow the rift system (NE –

SW) orientation but there are some faults with orientation of east – west and northwest-southeast .

The major lineament oriented along east – west that extends from Kassam River in the east through

Addis Ababa to Ambo in the west, cuts across the Western rift escarpment and uplifted its northern

block (Zennettin et al., 1978) which was during the late Miocene time. This lineament starts from the

western escarpment of the rift and goes even further to “Wollega” (Mengesha, et al, 1996). Entoto

silicics confined along this fault from the Entoto ridge, which forms surface water divide between

two vast basins in the country, namely Blue Nile (Abay) and Awash Rivers. The ridge forms the

northern boundary of the study area and the fault has a down throw to the south in the catchment.

Another major lineament oriented in Northwest direction & situated to the northeast of the Akaki

well field extends between Akaki and Dukem (following the main DebreZeit highway) is one of the

lineaments that do not follow the rift trend.

The other important lineament in the area is the Filwuha Fault. According to Kundo (1958), Morton

(1974) and Hailesellasie Girmay (1985), the fault has a trend of NE – SW, which is in accordance


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with the rift trend structures. Even though Morton (1974) identified the fault as having a down throw

to northwest, this was later disproved by Hailesellasie Girmay (1985) to be south based on detailed

mapping by resistivity survey of the fault. Moreover, he found the fault as having shallow depth,

covered by thin soil layer of about 1 to 4m, not vertical and estimated its throw to be 40m (the

approximate thickness of the welded glassy ignimbrite).

The measured dominant preferred orientation of joints occurring in different rock units in north

central part of the catchment is NNE – SSW, which is sub – parallel with the general trend of rifting

(Kebede Tsehayu and Tadesse Hailemariam, 1990)

The density of faults increases to the southeast of the rift valley. Therefore, some of the basaltic lava

and cinder cones situated to the Southeast and Northeast of the Akaki well field probably have

erupted through these fractures as they are concentrated along the major NE – SW trending fault

systems of Akaki and Dukem areas.

Figure 4.9: Typical fractured permeable volcanic rocks along the eastern proposed sewer line.

4.1.5.4 Soil

Soil composition is principally determined by the parent rock of the area. The sol type of the area is

principally governed by the geology of the area. All soils of the area are derivatives of the volcanic

rocks. Depending up on the local topographic and geo-morphological setup the thickness is highly

variable. In general, soil thickness increases towards the south as the elevation decreases and

deposition is high.

Thick residual and colluvial silty clay and clay soils dominate in the project area. The subsurface

infiltration condition of the area is mainly governed by the thickness and hydraulic conductivity of

the unconsolidated sediments overlying the weathered and fractured volcanic rocks. These rocks are


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relatively porous and have a relatively high hydraulic conductivity.

The composition and thickness of the unconsolidated deposits and soils vary as a function of

topography and geomorphology. Generally, the soil formations are broadly classified in to three

group namely the alluvial, residual and lacustrine dominantly clay deposits. The hydraulic

conductivity has been estimated to vary between 0.0017m/day to 0.00009m/ day in for the lacustrine

and alluvial deposits respectively (Addis Ababa Wastewater &Sewerage Master Plan study). In

most places, the main trunks are aligned along soil formations. However, in few areas rock cuts are

mandatory.

The detailed account of the soil geotechnical characteristics at the treatment plant is given in the

detailed design report related to foundation conditions. At the treatment plant, the dominant soil

type is silty clay. The permeability seems to be low to medium. In fact, the soils at the drying beds

are not watertight. It is likely that the liquid waste will infiltrate into the shallow groundwater

systems. Fortunately, immediately downstream of the treatment plant there are no wells and springs

being used for community water supply systems. However, if groundwater is to be developed at

relatively shallow depth downstream, the treatment plant has to consider this issue seriously.

Figure 4.10: Simplified soil map of Addis Ababa area

4.1.5.5 Seismicity

The Ethiopian Building Code Standard, EBCS-8, Design of Structures for Earthquake Resistance

classifies the country in to five different seismic hazard zones based on the seismic risk, from Zone 0

to Zone 4. Zone 4 is the severe one mainly assigned to the Great Rift Valley while Zone 0 is assigned


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to the western and Eastern portions of the Country. According to the seismic hazard classification,

Addis Ababa is categorized in ZONE 2. The minimum design peak acceleration to be considered in

design for Addis Ababa as per the code is 0.05g.

4.1.6 Water Resource and Quality

As stated above, there are a number of seasonal and perennial rivers that drain through the city. The

two most important rivers in the Kaliti catchment (Little Akaki and Big Akaki) which drain through

the cityare extremely polluted. One can find all sorts of solid and liquid wastes in these rivers. Many

point and non-point pollution sources exist in the sewer catchment.

With regard to water quality, the Akaki River and its main tributaries is considered as one of the

most pollutedrivers in the country due to the high pollution load from domestic and industrial

wastewaters. The Ministry of Water and Energy maintained a hydrometric network that generates

quantitative information on Big Akaki and Little Akaki Rivers flow. The EPA established a water

quality monitoring program on Awash River basin by selecting 22 sites that extends from upper

course to its termination near Afambo Lake. Results of the Akaki River monitoring have shown that

the water is chemically and bacteriologically highly polluted.

Review of recent findings of Akaki water quality assessment (Macha Chamargachew July 2009 &

Zerfie Mersha April 2008) also confirmed that Akaki River water is chemically, physically and

bacteriologically polluted.

With respect to concentration of heavy metals, sampling and analysis have been conducted for Cr,

Cd, Pb and Co in the months of November and January (ZerfeMersha 2008). The average value of

Cadmium in November was 0.009mg/1 and in January 0.0076mg/l where the concentration in both

cases is beyond the WHO standard limit of0.003mg/l. Similarly, the average value for Lead in

November and January was found out to be 0.028mg/1 and 0.069mg/l, respectively where the Lead

concentration in both cases is beyond the WHO standard limit of 0.01mg/l. The study also analyzed

other parameters to determine the chemical pollutants of the river with respect to COD, BOD, pH,

Iron, Manganese, Nitrate, Nitrogen, Phosphate, Sulfate, Phosphorus & Chloride (Macha, July 2009).

The result indicated that 100% of the COD, BOD, pH, Iron, TN, pH, Nitrate and NH3 were found

out to be above the standard limit. The result also showed concentration above the standard limit for

total Phosphorus, Manganese, and Chloride which is 91.1 %, 83.3 and 6.7%, respectively.

The southern part of Addis Ababa City, where the WTPs is located, is laid with lacustrine and

alluvial deposits with an estimated hydraulic conductivity of 0.00009m/ day (Addis Ababa

Wastewater and Sewerage Master Plan study). The project treatment area has been identified as

groundwater resource potential area, and this has been justified through drilling of 25 boreholes in

Akaki area that provided around 25% of the city’s water supply. In fact, these wells penetrate deeper

aquifers. However, shallow aquifer systems are likely to be polluted from wastewaters. The effect of

the Kaliti treatment plant on deeper groundwater is not well known. In fact, it is important to

consider the water tightness of the oxidation ponds and drying beds in the future.


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4.1.7 Wastewater Quality

4.1.7.1 Raw Wastewater Quality at the Treatment Plant

The historical long-term average data at the treatment plant was collected and used for predictive

modeling of the Kaliti wastewater treatment performance by Getenet Sewnet (2012). The wastewater

long-term quality data as presented in this work is shown in Table 4.2.

The treated and untreated wastewater used to be analyzed by AAWSA water quality laboratory.

However, in the last two years continuous analysis has not been done. For the sake of the ESIA

study, few samples were analyzed (see Table 4.3).

Table 4.2:Basic statistical description for historical raw wastewater at the KalitiWTP.

Table 4.3: Water quality analysis results of the project area

S. No Parameters Unit Code of Sample

Influent Effluent Little Akaki River

1 pH - 7.2 7.6 6.8

2 Total Dissolved Solids mg/l 283 236 262

3 Electrical conductivity µs/cm 573 476 938

3 Dissolved Oxygen mg/l Nil 7.2 4.6

4 Chemical Oxygen Demand (COD) mg/l 914 86 128

5 Biological Oxygen Demand (BOD) mg/l 434 20 31

6 Total suspended solids (TSS) mg/l 421 63 463

7 Total Volatile Solids (TVS) mg/l 364 54 137

8 Total non-volatile solids mg/l 57 9 336

9 Ammonia as NH3 mg/l 42.7 2.3 18.2

10 Nitrite Nitrogen as NO2 mg/l Nil 0.13 Nil

11 Nitrate Nitrogen as NO3 mg/l Nil 2.73 1.34

12 Hydrogen Sulfide as H2S mg/l 8.3 Nil Nil

13 Phosphate as PO4 mg/l 16.2 2.4 4.8

14 Sulfate as SO4 mg/l 13.8 18.4 23.7

15 Total Chromium as Cr mg/l Nil Nil 0.017

16 Chloride as Cl mg/l 38.5 36.4 23.5


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S. No Parameters Unit Code of Sample

Influent Effluent Little Akaki River

17 Acidity as CaCO3 mg/l 14 8 22

18 Total Alkalinity as CaCO3 mg/l 178 214 242

19 Total Hardness as CaCO3 Mg/l 136 124 94

Sampling and analysis was done on September 14, 2013

The wastewater quality result indicates that the effluent from the treatment plant and the Little Akaki

River are highly polluted. The treated water must meet national and international standards to release

it in to the nearby streams or to use it for irrigation purpose downstream. Under the current condition

the effluent is highly polluted. However, the Little Akaki River seems to be more polluted than the

effluent. As the samples were taken during the rainy season, it is likely to be diluted. The status of

the pollution is most likely much worst during the dry season.

4.2 The Biological Environment Baseline Conditions

4.2.1 Vegetation and Flora

Terrestrial vegetation and flora have been observed in KalitiWTP Project areas and its surroundings.

These vegetation, tree species and plantation forests are found along Little Akaki riverside,

residential houses, fences, institutional compounds, BehereTsige park and in the KalitiWTP

compound. Some of the tree species include Acacia Abyssinica, Cordia Africana, Dovyalis

Abyssinica, Ficusdahro, Ficussur, Olea Africana, Vernoniaamygdalina, Rhamnusprinoids,

Albizziagummifera, Rungiagrandis, Cupresseslustinca, Daturastramonium, Eucalyptus, grasses,

Sowdeniapolystachya etc. The vegetations, shrub types and Arundodonax that are grown on the

riverside are serving for stabilization of riverbanks.

4.2.2 Plantation Forest

There is a plantation forest in Lafto area of West trunk direction. The sewer line construction will

pass through this plantation forest. The plantation forest comprises dominantly exotic tree species

(mainly Eucalyptus and Cypress) which are in some parts interspersed or mixed with some patches

of bush lands and grasses. The tree species composition of the forestland is dominantly Eucalyptus

spp. (mainly E. camandulensis & E. grandis) and Cypress (Cupressuslusitanica). The indigenous tree

species include Acacia Abyssinica, Ficus sur.

4.2.3 Vegetables and Plants

Different types of vegetables are grown in farmland, homestead, at the riverbank and at the

downstream site. The residents use these vegetables for consumption and as source of income. These

vegetables include cabbage, pepper and Enseteventricosum. In some compounds of the project

affected persons, Rhamnusprinoides, Vernoniaamygdalina, and Daturastramonium are also grown

for purposes of local drink preparation and medicinal value.

4.2.4 Birds and Wildlife

Along the river line, in the facultative pond and on some of the trees, bird species are observed. The

bird species observed during the field survey include Ducks, Vultures, Doves, Pigeons, Egrets,


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Herons, Buzzards, Wattled ibis etc.The wildlife habitat has already been changed to settlement and

agricultural land.Hence, no major wildfire population and species is expected in the project area.

However, local people mentioned sporadic presence of wild animals such as common duiker,

warthog, baboons, spotted hyena, common fox and monkeys.

Figure 4.11: Photographs showing some of the biological elements o the project area (A: Floating vegetation grown

on the oxidation pond at the treatment plant indicating eutrophication that reduces the efficiency of the wastewater

treatment process; B: Bamboo grown along the course of the Little Akaki river which is also common at the treatment

plant; C: trees and shrubs being used as fences in many places in eastern and western trunk lines; D: Birds and

horses around the drying pond of Kaliti).

4.3 Socioeconomic Environment of Addis Ababa

4.3.1 Institutional and Administrative Context of Addis Ababa

In accordance with Articles 49(2) and 55(1) of the Constitution of the Federal Democratic Republic

of Ethiopia, Addis Ababa has the status of both a capital city and a state. Accordingly, it has its own

charter (Addis Ababa City Government Charter Proclamation No. 87/1997).

According to this charter, the Addis Ababa city Government has executive powers on all matters

other than those falling under the jurisdiction of the federal executive organs as well as judicial

powers on cases specifically provided for under its Charter.

The City Government has the powers to make laws and exercise judicial powers specifically vested

in it by the city charter and included in the details of the powers and functions of the Federal

Government executive organs.


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The City Government has the following administrative organs:

1) A Council;

2) An Executive Committee;

3) A Governor;

4) Office of the City Government;

5) Audit and Inspection Office;

6) Sectoral Executive Organs;

7) Sub-city and District administrative organs; and

8) Judicial organs as enumerated under Article 5 of this Charter.

Administratively, Addis Ababa city has 10 sub-cities and 116 Districts (districts). The following

simplified figure shows the division by sub-cities and districts.

Figure 4.12: Map of Addis Ababa city showing the division by sub-cities and district

The vision of the city is to ensure a safe and clean environment for a healthy and productive society

with improved access to social services and physical infrastructure. It aims to realize broad-based

growth of investment and employment through the development of sound economic infrastructure

and labour-intensive industrial technologies. It plays a dynamic role in facilitating national economic

growth. As a diplomatic capital of Africa, the city strives to provide quality services of international

standard. The sustainable achievement of these will be realized through combined and integrated

effort of the public, the private stakeholders and the community as a whole.

Growth trend

Until 1975, Addis Ababa was limited to an area designated today as a central Business District and

to some patchy areas along the five main roads leading to different provinces. Leap-frog type of

development was the main characteristics. In recent years the city is expanding dramatically. The

growth trend between 1975 and 2000 is shown in Figure 4.13.


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Figure 4.13: Growth trend of Addis Ababa between 1975 and 2000

4.3.2 Demographic Structure

As per the updated 2013 census, the population of Addis Ababa City is 3,103,999 out of which 1,479,000 are

male and 1,624,999 are female. The population density per square kilometer is 5890.1. The following table

shows the population of Addis Ababa by sub city:

Table 4.4 Basic demographic data of Addis Ababa

S. No. Sub-city Population

Area in

kilometer

Density/Square

kilometer

Male Female Total

1 Akaki-Kaliti 100,513 104,872 205,385 118.08 1,739.40

2 Nefas Silk Lafto 168,798 189,561 358,359 68.3 5,246.80

3 Kolfe-Keranio 235,257 250,695 485,952 61.25 7,933.90

4 Gulele 146,605 156,621 303,226 30.18 10,047.20

5 Ldeta 109,076 119,471 228,547 9.18 24,896.20

6 Kirkos 117,265 133,400 250,665 14.62 17,145.30

7 Arada 112,354 127,284 239,638 9.91 39,047.80

8 Addis Ketema 141,509 147,835 289,344 7.41 24,181.40

9 Yeka 183,083 209,698 392,781 85.98 4,568.3

10 Bole 164,540 185,562 350,102 122.08 2,867.8

Total 1,479,000 1,624,999 3,103,999 526.99 5,890.1

Source: Central statistic Authority, July, 2013


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The trunk sewer lines and the treatment plant are located in Akaki-Kaliti, “Nefas Silk-Lafto” and “Kirkos”

sub-cities. The total population in these sub cities is 814,409.

As per the 2007 population census, more than 50% of the population is less than 18 years of age.

Because of the fast population growth, the demand on natural resources is expected to increase

significantly, leading to natural resource degradation in and around the city. The highlands around

the city are densely populated. This has created significant pressure on land resources and resulted in

land and environmental degradation.

Table 4.5: Demographic Indicators of Addis Ababa, 2001 EC

S. No Demographic Indicators Indicator

values

1 Total fertility rate (children per women) 1.4

2 Life expectancy at birth 64.5

Male 62.6

Female 66.5

3 Annual population growth rate (in %) 2.1

4 Age dependency ratio 38

5 Sex ratio (number of male per 100 female) 90.8

6 Infant mortality rate (the number of deaths of infants under age one

per 000 live births)

45

7 Under five mortality rate (the number of deaths of infants under age

five per 1000 live births)

72

8 Crude death rate (the number of deaths per 1000 population) 6.9

9 Crude birth rate (the number of live births per 1000 population) 23

10 Female literacy rate 79.9

Source: Addis Ababa population images 2001 EC

As indicated in Table 4.5 above, on the average, the city population is growing at 2.1% annually,

and overall age dependency ratio was about 38%. The infant mortality rate is 45 out of 1000 live

births, while less than five mortality rate is 72 out of 1000 live births. The crude death rate was

estimated to be 6.9 out of the number of deaths in a year per 1000 mid-year population and the crude

birth rate is 23 out of the number of live births in a year per 1000 mid-year population (BOFED,

Addis Ababa population images 2001).

For the Addis Ababa city 662,728 households were counted and the average household size was

found to be 4.1. Although all Ethiopian ethnic groups are represented in Addis Ababa due to its

position as capital of the country, the largest groups include the Amhara (47.04%), Oromo (19.51%),

Gurage (16.34%), Tigre (6.18%), Silt'e (2.94%), and Gamo (1.68%). Languages spoken include

Amharic (71.0%), Oromiffa (10.7%), Gurage (8.37%), Tigrinya (3.60%), Silt'e (1.82%) and Gamo

(1.03%). In terms of religion the Ethiopian Orthodox believers account 74.7% of the population of

the city, while 16.2% are Muslim, 7.77% Protestant, and 0.48% Catholic.

4.3.3 Housing Conditions

According to the 2007 housing and population census of Ethiopia, there are 628,986 housing units in


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Addis Ababa city Administration. The following table shows the housing units of the three sub-cities

through which the trunk line passes and where the treatment plant is located.

Table 4.6 Housing types in the three affected Sub-Cities

S.N Sub-City Type of houses

Total Wood and mud Hollow block Corrugated iron

sheet

1 Akaki Kaliti 45749 36940 890 1298

2 Nefas Silk Lafto 75079 49936 1507 2874

3 Kirkos 52583 40238 558 2437

The housing condition of PAPs in the project area is categorized into four: hollow block, mud

houses; stonewall (masonry) with corrugated iron sheet roof and CIS wall by CIS roof. The

following table illustrates the condition of houses in the project area.

Table 4.7 Housing conditions and number of houses of PAPs

S.No. Type Number

of

houses

Area in square

meters

I. Partially affected

a Hollow block 36 1420.5

b Mud 125 4108.7

c Stone wall 2 40

d Corrugated iron sheet 34 12085

e Fences with different materials 41 -

II. Fully affected -

a Mud houses 29 977

b Mud and CIS 2 40

4.3.4 Major economic Activities

The major economic activities in Addis Ababa city are manufacturing industries (large-scale,

medium-scale, small-scale), trade, service and informal sectors.

The economy of Addis Ababa has been growing at an annual rate of 10% over the past decade.

Liberalization of the market coupled with sound macro-economic policies and measures accounted

for the high growth rate. Very recently, industry and the service sector have grown at a higher rate

than agriculture.

The economic activities in Addis Ababa are diverse. This is well illustrated in Table 4.8 that shows

the economic sector and people employed.

Table 4.8 Sectoral distribution of urban employment

S. Nr. Economic sector Nr. of people engaged

1 Trade and commerce 119,197


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2 Manufacturing and industry 113,977

3 Homemakers of different variety 80,391

4 Civil administration 71,186

5 Transport and communication 50,538

9 Education, health and social services 42,514

7 Hotel and catering services; 32,685

8 Agriculture 16,602

The city has recently been in a construction boom with tall buildings rising in many places. Various

luxury services have also become available and the construction of shopping malls has also

increased.

Active work force is vital for development. In the project area the work force is available. Most of

the people are self-employed and daily laborers with limited civil servants. The proposed project

may change the unemployment situation and will lower the rate of unemployed by providing

temporary job opportunity at the different stages of the project cycle. Table 4.9 summarizes the

employment situation of the three sub-cities where the project area is located.

Table 4.9 Economically active persons 10 years and above

Sub city

Economically active Economically inactive Activity rate

Male female total male female total male female

Akaki Kaliti 50898 40373 91271 22551 63934 86485 69.3 52.2

Nefas Silk Lafto 88634 78214 78214 34368 63070 97438 72.1 55.4

Kirkos 64949 59975 124924 25501 44411 69912 71.8 57.5

Source: Population and housing census of 2007

4.3.5 Land use Pattern

The trunk line passes through gravel, cobblestone and asphalt roads in most parts of the area. It

touches mud, hollow block and corrugated iron sheet houses and fences of households and

organizations. Representative plates showing the land cover and use patterns in the project area are

indicated in section 4.2 and the generalized land-use map of Addis Ababa is given in Figure 4.4.

4.3.6 Educational Facilities

According to the Central Statistics Authority abstract of 2010/2011, there are many primary and

secondary governmental and non-governmental schools in Addis Ababa. The total students in

governmental and non-governmental schools is 298,911 and 327,854, respectively. According to the

2007 national census, adult literacy in Addis Ababa for men and women is 93.6% and 79.95%,

respectively. These figures are the highest in the nation for both sexes. Table 4.10 shows the status of

education in the project affected subcities.


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Table 4.10 Status of education

Sub-city Both sexes Male Female Percent

Both

sexes

Literate All

male

literate All

female

literate Both

sexes

male female

Akaki Kaliti 166,653 137,281 81,203 71,829 85,450 65,452 82.4 88.5 76.6

Nefas Silk

Lafto

290,639 248,164 135,967 123,872 154,672 124,297 85.4 91.1 80.4

Kirkos 208,828 185,044 97,213 92,043 111,616 93,001 86.6 94.7 83.3

Source: Population and housing census of 2007

4.3.7 Health Facilities

The health services in the city administration are provided by the government and the private sectors.

The current situation of the health facilities in the city is shown in the following table (Table 4.11):

Table 4.11 Health facilities in the City Administration of Addis Ababa

S. No. Type of facility Government Non-government

1 Hospitals 6 30

2 Clinics NA 650

3 Health centers 52 NA

4 Health post NA

Source: CSA, Statistical abstract 2011/2012 page, 320.

There are different health professionals working in the health facilities. The following table

summarizes the professionals working in the health service sector in the city.

Table 4.12 Number of health service providers

S.N Type Number

1 Doctor 170

2 Health officer 139

3 Nurse 1,900

4 Pharmacist 50

5 Sanitarians 46

6 Laboratory technician 109

7 Pharmacy technician 140

Source: CSA, Statistical Abstract 2011/2012

There are various drug distributers, drug trading organizations and drug and medical suppliers in the

city. In total, there are 189 pharmacies, 232 drug shops and 1 rural drug vender. There are also 169

importers and wholesalers and 8 manufacturers.

4.3.8 Road Facilities

The road network of the city administration is showing improvement from time to time. The total

road network facility of the city is 4,148 kilometers (up to June, 2013). This accounts for 15.69%

coverage of the city. The pedestrian roads and drainage structures in the city are 1,596 and 3,500


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kilometers, respectively. The current situation of the road facility in the city is indicated in Table

4.13 below.

Table 4.13 Road facilities of the city

S. No. Type Unit of measure Amount

1 Asphalt kilo meter 2002

2 Coble stone kilo meter 727

3 Gravel kilo meter 1419

Total 4148

Source: Addis Ababa Road Authority

4.3.9 Telecommunication Facilities

Ethio-Telecom is the only service provider of telecommunication services in Ethiopia including

Addis Ababa.

Types of services provided are fixed line, mobile GSM pre-paid, CDMA pre paid, voice, voice and

data. Broad band, narrow band and total data internet services are also provided. The subscribers are

11,509,366 in the country (National phone directory 2012).

4.3.10 Water Supply

The water supply for the city comes from different sources. The most important ones are the surface

dams and groundwater. There are four dams around Addis Ababa. About a quarter of the water

supply comes from groundwater. The use of groundwater is growing rapidly in recent years.

There are 250,000 customers of AAWSA. According to the 2007 national census, 98.64% of the

housing units of Addis Ababa had access to safe drinking water.

4.3.11 Sanitation Facilities

The sanitation condition in the city of Addis Ababa is not good. As stated above the liquid and solid

waste disposal facilities in the city are in their infancy. According to the 2007 national census, 14.9%

of the housing units of Addis Ababa has flush toilets, 70.7% pit toilets (both ventilated and

unventilated), and 14.3% had no toilet facilities.

Recently, all districts are working to improve the solid waste facilities. Solid wastes are being

collected by employed persons in each district. The solid waste is hauled and dumped by trucks in

Koshe, which is located in the western part of the city.

4.4 Gender Issue

Keeping the household environmental and personal sanitation is mainly the role of women in the

society. The sanitary condition is directly related with the health of the family and the community.

Children's health is very much in danger in poor sanitation situation. As child care and upbringing is

the role of women, the project implementation will reduce the load of women by improving the

sanitation situation of the communities in the project area in particular, and in the city in general.


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4.5 Project Affected Persons

The project affects persons directly and indirectly both positively and negatively. The total family

heads expected to be affected one way or another are 269. The details are indicated in chapter 6

(Volume I) and in the RAP report (Volume II). Brief description of the fully and partially project

affected persons is given below.

4.5.1 Fully Affected Persons

Fully affected refers here to persons that are to be resettled. The total households to be resettled are

31 in number. 22 households are located in the Akaki Kaliti Sub city (21 in District 6 and 1 in

District 5) and 9 are found in Nefas Silk Lafto Sub city (8 in District 10 and 1 in District 12). In

terms of ownership, 21 are male and 10 are female. The household family members are 189 in total,

out of which 93 are male and 96 female.

According to the present survey, most of the fully affected persons are venders and daily laborers.

The PAPs in these districts share similar psychological and social characteristics and they are nearly

in the same economic status.

One of the most outstanding issues in the environmental impact assessment studies is the

resettlement of fully affected households. The consultant has given due consideration for this and

resettlement action plan report is prepared. In connection with this, relevant offices have been

consulted as to how these families are being resettled. In line with the proclamation of 455/2005,

guidline135/1999 and guidline3/2002 these families (households) will be resettled in their respective

sub-cities where all basic public facilities will be made available. In the course of resettlement, they

will be consulted by resettlement committees of their sub-cities to know their needs and choices.

Their houses and properties to be affected will be estimated based on well established procedures

and rules set by the City Administration. If the estimation of the house is less than ETB 51,000, all

will be given this amount. The Birr 51,000 is set as the minimum amount to be paid for the

reconstruction of houses. If the estimation is over ETB 51,000, the estimated amount will be paid as

compensation. In addition,

For those who need to build their own houses with the compensated money, land will

be provided in the designated area in the respective sub-cities.

For those who need condominium houses, they can buy with the compensation money

they get.

These persons are going to be resettled in places where there are developed infrastructures, social

services which is likely to be better than the existing situation.

4.5.2 Partially Affected Persons and Organizations

The partially affected persons are those who lose some property such as trees and fences and

attached structures but do not need resettlement. The partially affected persons live along the sewer

lines in Akaki- Kaliti Sub city (Districts 5 and 6), in Nefas Silk-Lafto Sub city (Districts 8, 9, 10 and

12) and in Kirkos Sub city in District 3.


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These people have more or less similar social and economic status. They are mainly civil servants,

traders, private company employees and self-employed in different informal sectors. These PAPs

will be compensated for lost property as per the rules and regulations of the city administration as

indicated above. The detail of the PAPs and affected properties is given in Annex 1.

The list of project affected people and major stakeholders and institutions is given in the RAP report.

Major internal and external stakeholders are also listed and described in Chapter 7.

With regard to people living downstream of the treatment plant, there is no direct sever impact.

However, the opinion of the community living downstream has been surveyed and addressed in the

RAP report. In general, the number of households living downstream of the treatment plant is very

small. They are mainly living in mud houses. The majority of them grow vegetables by using

wastewater effluent and the Little Akaki river water .

Figure 4.14: Some field activities related to socioeconomic surveying, asset enumeration and project area observations

(A: Key informant interview; C: Asset enumeration along the sewer lines; C: Communities working at the drying bed;

D: Site visit of the treatment plant and its environs).

As the new project will be implemented within the exiting treatment plant compounds, there are no

people who will be resettled in downstream areas. The number of houses to be fully affected along

the sewer lines is also limited. Most of the sewer line passes through fences (wood and corrugated

iron sheet), gravel and cobblestone roads and through vegetable gardens. See the detailed

socioeconomic profile of the project area in the RAP report (Volume II).


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5 ANALYSIS OF PROJECT SPECIFIC ALTERNATIVES

5.1 Project Alternatives

Addis Ababa Water and Sanitation Development and Rehabilitation Project Office has prioritized the

installation of the major sewer trunk lines that can have a capacity to accommodate ultimate

wastewater flow rate instead of expanding localized wastewater collection system. A WTP has to be

designed and sized for a flow rate of 100,000m3/dthat would fit on the available site, i.e., the existing

WTP at Kaliti.

Accordingly, the study and design of the project has been carried out by Morrison Hershfield

Limited, in association with ARMA Consulting Engineers PLC.

So, it is clear that in the scope of the design work, alternative projects were not included. This may

be due to the nature of this project which focuses on the expansion of the existing Kaliti wastewater

collection and treatment system. The choice seems to be governed partly by the availability of land

in the premises of the existing WTP and the current impressive building development in the

catchment area.

However, alternatives were considered within the above specified scope. These included alternative

sewer trunk routes, alternative sewer pipe materials and alternative wastewater treatment

technologies.

5.2 No Action/ Without Project Alternative

The current Addis Ababa City population served by proper wastewater disposal system is too low,

less than 30,000 connection to Kaliti WTP site. There is some evidence and potential risk of surface

and ground water pollution by wastewater from domestic, agricultural and industrial facilities. The

do nothing scenario will compromise or retard the long-term city development plan, since a proper

and well maintained sanitation system is fundamental to achieving the full benefit of other

development initiatives and improve the status of the city.

The existing lagoon treatment system is already operating beyond its design capacity resulting in less

effective treatment with the potential of releasing effluent, that does not meet treatment standards, to

downstream area. Reactive sewer pipe installation for servicing selected locations without clear

future planning for the sewage collection system has led to undersized mains due to increased

connections and higher density. The under sized sewers overflow in the streets and into the city

water courses and streams. The situation is unhealthy and the City can be exposed to a major disease

outbreak. Many are served by latrines and leaking septic tanks. Leaking tanks pollute the ground

water. The population of the city is constantly increasing. Increased density has resulted in problems

for the septic pump-out trucks to get to and service the new high volume customers. The aesthetics of

the City is also affected as residents and visitors see their local rivers biologically “die” and turn into

open sewers. If no action is taken, the wastewater treatment, the sanitary situation and the aesthetics


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of the city and the groundwater quality will deteriorate. Already, hauled sewage is being dumped in

drying beds and the effluent is being discharged without treatment. If the current situation continues,

the need of using (malfunctioning) septic systems and for wastewater disposal will rise in order to

cope up with increasing treatment capacity requirements. This will worsen the situation of Little

Akaki River downstream of the plant and the agricultural situation in the area where this river water

is used for irrigation.

The potential social and socio economic benefits to the city population and improvement in quality

of life couldn't be realized without the project.

The only advantages from environmental angle are that tree cutting at some locations and the soil

disturbance during trenching will be avoided. “No project” scenario case will also avoid social

impacts due to the implementation of the project as there will be impact on some private properties.

The "do nothing" alternative is completely unacceptable, the potential social, socio economic and

environmental benefit of the project implementation are far outweighing the potential adverse

impacts that can be controlled and minimized to acceptable level through implementing the proposed

environmental mitigation and management plan.

5.3 As Proposed Alternative

If implemented, the proposed project will relieve existing facilities from excess load leading to

overflow of sewage waste that has affected the environment of the city and the wellbeing of its

inhabitants. Since the wastewater handling capacity will be increased and some additional areas will

be linked to the sewer line, more people will be served and the city’s hygienic status will be

improved. Currently, the effluent that is coming out of the existing treatment plant is not properly

treated. Leachate from drying beds is directly sent to Little Akaki River. If the new project is

implemented the effluent will be released after undergoing proper treatments so that it meets the

standards set by EPA. This will improve the usability of the water and also the sludge for agricultural

purposes. It will also create a better condition for the aquatic ecology in Little Akaki River.

In addition, the project will protect soil and groundwater contamination, improve the air quality and

will create new job opportunities during all of the project phases. The number of units that will be

connected to the sewage system will increase. As a result, the city would become cleaner to live in.

5.4 Alternative Design Options

5.4.1 Sewer trunk Lines

All sewer trunk expansions cannot be done simultaneously because of the significant investment that

is required and the complexity of the project management as most of the upgrading has to be

executed within the developed city centers. Therefore, a phase by phase expansion approach has to

be followed. Accordingly the sewer system is subdivided into 4 trunks and subsequently prioritized.


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These are:

Kaliti Main(southern) Trunk Upgrades

Eastern Kaliti Catchment Sewer Trunk

Western Kaliti Catchment Sewer Trunk

Central Kaliti Catchment Main Trunk

The trunk route alternatives were analyzed and the selection was made based on the following

constraints:

The preferred flow system is only gravity system

The proposed sewer trunks are large diameter.

The unstructured nature of the roads and buildings

The presence of local creeks,

the management of compensation process for private properties to obtain a right-of-way for

the construction of the sewer trunk lines

5.4.1.1 Eastern Kaliti Catchment Sewer Trunk

This is a new Sewer Trunk line that extends from the Kaliti Ring Road to the Bole Bridge on Africa

Avenue with a total length of approximately 10.45 km.

The selected route during the initial surveying work was along the existing sewer line. However, this

alternative was not chosen because of private property encroachments into the right-of-way. A

number of routing options were reviewed to select a route that would minimize constructability

issues. A second alternative route was along the Bulbula riverbank that extends to the south on the

east side of Joseph Church and “Saris-Addis Sefer” before it crosses the Ring Road to parallel the

Rail Way east of “Chimad” warehouse. Two routing options on either side of Bulbula River were

also considered for the northern section of this trunk, between Bole Bridge and the Bulbula Ring

Road Bridge. AAWSA has chosen the western branch along the existing right-of-way from Bole

Bridge to the “Wengelawit” Building as the preferred route to be designed.

5.4.1.2 Western Kaliti Catchment Sewer Trunk

This is also a new sewer line. Placing this trunk along the western bank of the Akaki River was

proposed in the preliminary design report. However, after a reconnaissance survey, this route was

found to be very difficult for construction and the decision was made with AAWSA to follow the

existing main right-of-way on the east side of the river.

The preference for use of gravity system is commendable since it will avoid problems associated

with power interruptions and will minimize the operating cost of the sewer lines in the whole lifetime

of the sewer line. Given the constraints indicated above and the long-term advantage, the selected

routes for the sewer trunk lines are appropriate.


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5.5 Treatment and disposal Alternatives

A number of treatment technologies have been examined by the designer. Table 5.1 provides the

total ranking for each of the processes that were considered in the Preliminary Report.

Table 5.1: Selection Matrix Results

Treatment Technology Ranking

Oxidation Ditch 1850

Trickling Filter 1780

Existing Lagoon Upgrade 1775

UASB with Trickling Filter 1680

Moving Bed Bioreactor (MBBR) 1585

Conventional Activated Sludge 1125

Although the Oxidation Ditch had the top score, this option required larger area than is available in

the existing Kaliti WTP. In addition, it makes future expansions within the site difficult to achieve.

The second highest weighted option, Trickling Filter technology, is relatively simple to operate and

has reasonable operating and maintenance costs. The preliminary estimate for its footprint shows that

it can be implemented onto the existing site without disrupting the existing wastewater treatment

operation and there is space for enough trains to treat up to 100,000 m3/d at a BOD load of 470

mg/L. In addition Trickling filters can provide the required amount of BOD removal and can have

good resistance to fluctuations in BOD loads.

The third option included upgrades to the existing lagoon including retrofits with an anaerobic pond

or installing surface aerators. Both of these options increase the efficiency and treatment using a

lagoon type process. However, even these efficiencies do not reduce the surface area required to

provide proper treatment for the flows needed for the city to fit within the area available. Cost

Estimates for the Top Three Options

The cost estimates for the top three treatment options are indicated in Table 5.2.

Table 5.2: Construction Cost Estimates for Top Three Options

Treatment Technology Estimated Construction Cost (ETB)

Oxidation Ditch 1,850,456,500

Trickling Filter 1,246,356,500

Existing Lagoon Upgrade 867,964,500

The costing has assumed the availability of additional land for the planned future expansion and for

the second phase of the oxidation ditch. The detailed design was therefore done for the Trickling

Filter technology. The high rate trickling filter was the option that was recommended in the

Feasibility study document of the proposed Project as the best suited to the site and particularities of

the wastewater to be treated at Kaliti WTP.


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The major disadvantages of Trickling Filters include its lower purification efficiency for equal BOD

loading, risk of clogging, sensitivity to temperature, etc.

However, the Client has informed the ESIA team that based on inputs on the selected technology

from some stakeholders, a UASB is to be included before the Tricking Filter. This additional

technology is compact, has high chemical oxygen demand (COD) removal efficiency at shorter

retention times, low construction cost, simple operation and minimal pumping requirement. It has the

advantage of producing biogas which can be used for the energy requirement of the plant thus

lowering the operation cost. The coupling of these two technologies seems a good option in view of

the existing constraints while fulfilling the required effluent requirements.

5.5.1 Comparison of the commonly used wastewater treatment systems

The effectiveness of wastewater treatment facilities has been judged on the basis of contaminant

removal per unit cost and in terms of net improvement in receiving water quality.

The major criteria for comparative evaluation include (Table 5.3):

Technical

Environmental

Economic

Socio-cultural

In conclusion, the selected process combination of Kaliti WTP is very good in terms of technical,

environmental, economic and socio-cultural performance criteria.


80


Table 5.3 Comparison of the commonly used wastewater treatment systems

No,. Criteria Oxidation

ditch

Trickling

filter

Existing

lagoon

upgrade

UASB UASB

with

trickling

filter

Moving

bed

bioreactor

Conventional

Activated

sludge

Activated

sludge with

Nitrification,

denitrification

and

phosphate

removal

Constructed

wetland

UASB with

Trickling

Filter and

Constructed

wetland

Technical Criteria

1 Treatment performance XX1 XX XX XXX XXX XXXX XX XXXX X XXXX

2 Flexibility/Adaptability X X XX X XX XX XX XX XXX XXX

3 Durability XXXX XXXX XXXX XX XXX X XX XX XX XXX

4 Ease of construction/low tech XXXX XX XXXX X X X X X XXX XX

5

Operation and maintenance

requirements XXX XXX X XX X X X XXX XX

6 Reliability/Security XX XXX XXX X XXX X XX X XXX XXX

Economic Criteria

1 Costs XX XX XXXX X XX X X X XXX XXX

2 Labor XXX XX XXX X XX X X X XXXX XXX

Environmental Criteria

1 Biodiversity/land fertility

2

Export of problems in time

and space XX XX X XXX XXXX XXX XX XXXX XXXX XXX

3 Integration in natural cycles XX XX XXX XX XX XX XX XX XXXX XXXX

4 Land area required/space X XXXX X XXXX XXX XXXX XX X XX XXX

5 Odor, Noise, Insect, visual X XXX X XX XXX XX XX XXX XX XXX

6 Optimal water utilization X XX X XX XX X XX XXX XXXX XXXX

1X: Fair; XX: Good; XXX: Very good; XXXX: Excellent


81


No,. Criteria Oxidation

ditch

Trickling

filter

Existing

lagoon

upgrade

UASB UASB

with

trickling

filter

Moving

bed

bioreactor

Conventional

Activated

sludge

Activated

sludge with

Nitrification,

denitrification

and

phosphate

removal

Constructed

wetland

UASB with

Trickling

Filter and

Constructed

wetland

7 Optimal nutrient utilization X X X XXX XXX XXX XXXX X X XXX

8 Optimal energy utilization X X X XXXX XXXX XXX X X X XXXX

9 Pathogen removal/Health X X X X X X X X XXX XXX

10 Pollution prevention XX XX XX XX XXX XXX XX XXX XXX XXX

11

Control of BOD/COD

emission XX XX XX XXX XXX XXX XXXX XXXX XXX XXXX

12 Control of Nutrient release X XX XX X XX XX X XXXX XXX XXX

13

Control of Heavy metals

release X X XXX X X X X X XXXX XXXX

14

Control of others pollutant

release X X XX X XX X X X XXXX XXX

15 Sludge/Waste production X XX X X XX X X X XXXX XXX

16 Use of chemicals XXX XXX XXX

Social-cultural Criteria

1

Competence/Expertise

requirement XXXX XX XXXX X X X X X XXX XX

2 Institutional requirements XXXX XX XXXX X X X X X XXX XX


82


6 ENVIRONMENTAL AND SOCIAL IMPACTS IDENTIFICATION,

ANALYSIS AND MITIGATION MEASURES

When identifying the potential impacts of a new project on the existing environment, it is necessary

that it should be measured against the existing baseline conditions. For convenience, the project is

divided into three parts: sewer trunk line, the wastewater treatment plant and the area downstream of

the treatment plant. Thus, in this chapter, the impacts that are expected to result at each stage of the

project activities are identified and analyzed for each of these three project parts in relation to the

various stages of their implementations.

6.1 Checklist of Potential Environmental and Social Impacts

In view of the above arguments, checklists of probable impacts due to the proposed Project have

been drawn up for each of the project parts (the Sewer trunk line area, the WTP, and the area

downstream of the WTP) in Table 6.1, 6.3 and 6.4, respectively. The list of properties that will be

affected by the project during the mobilization phase in the Sewer trunk line area part of the project

is given in Table 6.2.

Table 6.1 Check List of Potential Environmental Impacts in the Sewer trunk Line Part

Impact on/ issue

Criteria

S

p

a

t

i

a

l

E

x

t

e

n

t

D

u

r

at

io

n

significance Probability of

occurrence

Reversibility Adverse/beneficial Objective

/Subjective

Sewer trunk Line-Mobilization Phase

Ph

ysi

cal

Air

Quality

S

i

t

e

s

p

e

c

i

f

i

c

S

h

or

t

te

r

m

lo

w

certa

in

re

ve

rsi

ble

adverse subj

ecti

ve

Water - - No - - - -


83


Impact on/ issue

Criteria

S

p

a

t

i

a

l

E

x

t

e

n

t

D

u

r

at

io

n


occurrence


/Subjective

bodies ne

Soil - - No

ne

- - - -

Biological Flora S

i

t

e

s

p

e

c

i

f

i

c

S

h

or

t

te

r

m

Lo

w

possi

ble

re

ve

rsi

ble

adverse subj

ecti

ve

Fauna

(terrestri

al )

- - No

ne

- - - -

Socio-

economic

Tempor

ary

employ

ment

L

o

c

a

l

S

h

or

t

te

r

m

lo

w

Certa

in

Re

ve

rsi

ble

Beneficial Sub

jecti

ve

Loss of

property

and

housing

units

S

i

t

e

s

p

e

c

i

f

i

c

p

er

m

a

n

e

nt

hi

gh

Certa

in

irr

ev

ers

ibl

e

adverse obje

ctiv

e

Others Noise S

i

t

e

s

p

e

S

h

or

t

te

r

m

lo

w

Certa

in

Re

ve

rsi

ble

Adverse Obj

ecti

ve


84


Impact on/ issue

Criteria

S

p

a

t

i

a

l

E

x

t

e

n

t

D

u

r

at

io

n


occurrence


/Subjective

c

i

f

i

c

Safety(

Acciden

ts)

S

i

t

e

s

p

e

c

i

f

i

c

--

--

-

hi

gh

Possi

ble

- Adverse Sub

jecti

ve

Sewer trunk Line-Construction Phase

Physical Air

Quality

s

i

t

e

s

p

e

c

i

f

i

c

sh

or

t

lo

w

certa

in

re

ve

rsi

ble

adverse subj

ecti

ve

Water

bodies

s

i

t

e

s

p

e

c

i

f

i

c

m

ed

iu

m

lo

w

possi

ble

re

ve

rsi

ble

adverse subj

ecti

ve


85


Impact on/ issue

Criteria

S

p

a

t

i

a

l

E

x

t

e

n

t

D

u

r

at

io

n


occurrence


/Subjective

Soil s

i

t

e

s

p

e

c

i

f

i

c

m

e

di

u

m

m

ed

iu

m

possi

ble

re

ve

rsi

ble

adverse subj

ecti

ve

Biological Flora s

i

t

e

s

p

e

c

i

f

i

c

p

er

m

a

n

e

nt

m

ed

iu

m

certa

in

irr

ev

ers

ibl

e

adverse obje

ctiv

e

Fauna

(terrestri

al,

avian)

s

i

t

e

s

p

e

c

i

f

i

c

m

e

di

u

m

lo

w

High

ly

prob

able

re

ve

rsi

ble

adverse subj

ecti

ve

Socio-

economic

employ

ment

l

o

c

a

l

m

e

di

u

m

lo

w

certa

in

- beneficial Sub

jecti

ve

Property

loss

s

i

t

p

er

m

hi

gh

certa

in

irr

ev

ers

adverse obje

ctiv

e


86


Impact on/ issue

Criteria

S

p

a

t

i

a

l

E

x

t

e

n

t

D

u

r

at

io

n


occurrence


/Subjective

e

s

p

e

c

i

f

i

c

a

n

e

nt

ibl

e

Oth

ers

Noise s

i

t

e

s

p

e

c

i

f

i

c

sh

or

t

lo

w

Certa

in

Re

ve

rsi

ble

Adverse Sub

jecti

ve

Health L

o

c

a

l

s

h

o

rt

m

ed

iu

m

Possi

ble

- Adverse Sub

jecti

ve

Safety(

Acciden

ts)

S

i

t

e

s

p

e

c

i

f

i

c

--

--

hi

gh

Possi

ble

- Adverse Sub

jecti

ve

Traffic

congesti

on/

inconve

nience

s

i

t

e

sh

or

t

lo

w

Possi

ble

Re

ve

rsi

ble

Adverse Sub

jecti

ve


87


Impact on/ issue

Criteria

S

p

a

t

i

a

l

E

x

t

e

n

t

D

u

r

at

io

n


occurrence


/Subjective

s

p

e

c

i

f

i

c

Sen

siti

ve a

rea

s

SA

Embass

y

s

i

t

e

s

p

e

c

i

f

i

c

s

h

o

rt

hi

gh

Certa

in

Re

ve

rsi

ble

Adverse obje

ctiv

e

Mosque s

i

t

e

s

p

e

c

i

f

i

c

s

h

o

rt

hi

gh

Certa

in

Re

ve

rsi

ble

Adverse obje

ctiv

e

ring

road/rail

way line

s

i

t

e

s

p

e

c

i

f

i

c

s

h

o

rt

m

ed

iu

m

Certa

in

Re

ve

rsi

ble

Adverse obje

ctiv

e


88


Impact on/ issue

Criteria

S

p

a

t

i

a

l

E

x

t

e

n

t

D

u

r

at

io

n


occurrence


/Subjective

existing

sewer

line

L

o

c

a

l

m

e

di

u

m

hi

gh

possi

ble

re

ve

rsi

ble

adverse subj

ecti

ve

Sewer trunk Line-Post Construction phase

Ph

ysi

cal

Air

Quality

s

i

t

e

s

p

e

c

i

f

i

c

sh

or

t

no

ne

certa

in

re

ve

rsi

ble

adverse subj

ecti

ve

Soil s

i

t

e

s

p

e

c

i

f

i

c

sh

or

t

lo

w

possi

ble

re

ve

rsi

ble

adverse subj

ecti

ve

Water

bodies

s

i

t

e

s

p

e

c

i

f

i

c

sh

or

t

lo

w

possi

ble

re

ve

rsi

ble

adverse subj

ecti

ve

Bi

ol

og

ica l

Flora s

i

m

e

lo

w

High

ly

re

ve

adverse subj

ecti


89


Impact on/ issue

Criteria

S

p

a

t

i

a

l

E

x

t

e

n

t

D

u

r

at

io

n


occurrence


/Subjective

t

e

s

p

e

c

i

f

i

c

di

u

m

prob

able

rsi

ble

ve

Fauna

(terrestri

al )

- - - - - - -

Socio-

economic

employ

ment

l

o

c

a

l

sh

or

t

lo

w

Certa

in

- beneficial Sub

jecti

ve

Oth

ers

Noise s

i

t

e

s

p

e

c

i

f

i

c

sh

or

t

lo

w

Certa

in

Re

ve

rsi

ble

Adverse Sub

jecti

ve

Health s

i

t

e

s

p

e

c

i

f

i

c

m

e

di

u

m

lo

w

possi

ble

Pa

rtl

y

re

ve

rsi

ble

adverse subj

ecti

ve

Safety( s -- hi Possi - Adverse Sub


90


Impact on/ issue

Criteria

S

p

a

t

i

a

l

E

x

t

e

n

t

D

u

r

at

io

n


occurrence


/Subjective

Acciden

ts)

i

t

e

s

p

e

c

i

f

i

c

-- gh ble jecti

ve

Sewer trunk Line-Operation phase

Physical Soil S

i

t

e

s

p

e

c

i

f

i

c

lo

n

g

lo

w

possi

ble

re

ve

rsi

ble

adverse subj

ecti

ve

Water

bodies

s

i

t

e

s

p

e

c

i

f

i

c

lo

n

g

lo

w

possi

ble

re

ve

rsi

ble

adverse subj

ecti

ve

Biological Flora s

i

t

e

s

p

lo

w

lo

w

possi

ble

re

ve

rsi

ble

beneficial subj

ecti

ve


91


Impact on/ issue

Criteria

S

p

a

t

i

a

l

E

x

t

e

n

t

D

u

r

at

io

n


occurrence


/Subjective

e

c

i

f

i

c

Socio-

economic

Habitabi

lity of

the City

L

o

c

a

l

lo

n

g

hi

gh

Certa

in

- beneficial Sub

jecti

ve

Other Health L

o

c

a

l

lo

n

g

hi

gh

certa

in

- beneficial Obj

ecti

ve

Sewer trunk Line-Decommissioning phase

Ph

ysi

cal

Air

Quality

s

i

t

e

s

p

e

c

i

f

i

c

sh

or

t

lo

w

certa

in

re

ve

rsi

ble

adverse subj

ecti

ve

Water

bodies

s

i

t

e

s

p

e

c

i

f

i

c

m

ed

iu

m

me

di

u

m

possi

ble

re

ve

rsi

ble

adverse subj

ecti

ve

Soil s

i

t

e

sh

or

t

lo

w

possi

ble

re

ve

rsi

ble

adverse subj

ecti

ve


92


Impact on/ issue

Criteria

S

p

a

t

i

a

l

E

x

t

e

n

t

D

u

r

at

io

n


occurrence


/Subjective

s

p

e

c

i

f

i

c

Biological Flora s

i

t

e

s

p

e

c

i

f

i

c

lo

w

lo

w

possi

ble

re

ve

rsi

ble

adverse subj

ecti

ve

Socio-

economic

employ

ment

l

o

c

a

l

sh

or

t

lo

w

Certa

in

- beneficial Sub

jecti

ve

Others Noise s

i

t

e

s

p

e

c

i

f

i

c

sh

or

t

lo

w

Certa

in

Re

ve

rsi

ble

Adverse Sub

jecti

ve

Health) L

o

c

a

l

sh

or

t

hi

gh

Possi

ble

Re

ve

rsi

ble

Adverse Sub

jecti

ve

safety L sh lo Possi Re Adverse Sub


93


Impact on/ issue

Criteria

S

p

a

t

i

a

l

E

x

t

e

n

t

D

u

r

at

io

n


occurrence


/Subjective

(Accidents) o

c

a

l

or

t

w ble ve

rsi

ble

jecti

ve

Traffic

inconve

nience

L

o

c

a

l

sh

or

t

lo

w

Possi

ble

Re

ve

rsi

ble

Adverse Sub

jecti

ve

Table 6.2 List of properties that will be affected/damaged during the mobilization phase2

Description Unit Quantity

Housing units with block wall& CIS roof m2

1510

Housing units with mud wall & CIS roof m2

5200

Housing units with stone wall & CIS roof m2 40

Housing units with CIS wall and roof m2 3914

Foundation for housing unit m2 181

Septic tanks m3 348

Fuel tanks m3 208

Fence made with stone m2 610

Fence made with CIS m2 2000

Fence made with block m2 1428

Stone retaining wall m2 90

Eucalyptus trees piece 397

Telephone poles piece 26

Electric poles piece 89

Asphalt road m2 1719

Cobblestone road m2 616

Gravel road m2 2349

Table 6.3 Check List of Potential Environmental Impacts in the Wastewater Treatment Plant

2 The full list of PAPs is given in Annex 2


94


Impact on/ issue Criteria

Spatial

Extent

D

u

r

at

io

n

significance probability of

occurrence

Reversibility Adverse/beneficial Objectiv

e

/Subjecti

ve

WTP-Mobilization Phase

Physical

Air

Qu

alit

y

site specific sh

or

t

l

o

w

ce

rta

in

re

ve

rsi

bl

e

adverse s

u

b

j

e

c

t

i

v

e

Soil site specific sh

or

t

l

o

w

ce

rta

in

re

ve

rsi

bl

e

adverse s

u

b

j

e

c

t

i

v

e

Wa

ter

bod

ies

- - - - - - -

Biological

Flo

ra

site specific p

er

m

a

n

e

nt

l

o

w

po

ssi

bl

e

re

ve

rsi

bl

e

adverse s

u

b

j

e

c

t

i

v

e

Fau

na-

terr

estr

ial

- - - - - - -

Socio-

economic

Em

plo

ym

ent

Local sh

or

t

l

o

w

C

ert

ai

n

- beneficial s

u

b

j

e

c

t

i

v

e

Bio

gas

gen

erat

City wide L

o

n

g

h

i

g

h

ce

rta

in

beneficial O

b

j

e


95


ion

Sludge for

pyrolysis or

fertilizer use

te

r

m

c

t

i

v

e

Others

Hea

lth

local sh

or

t

l

o

w

po

ssi

bl

e

R

ev

er

si

bl

e

adverse s

u

b

j

e

c

t

i

v

e

Noi

se

Local sh

or

t

l

o

w

Po

ssi

bl

e

R

ev

er

si

bl

e

adverse s

u

b

j

e

c

t

i

v

e

Saf

ety

Acc

ide

nts

Local --

--

h

i

g

h

Po

ssi

bl

e -

R

ev

er

si

bl

e-

adverse s

u

b

j

e

c

t

i

v

e

WTP-Construction Phase

Physical Air Quality s

i

t

e

s

p

e

c

i

f

i

c

sh

or

t

l

o

w

ce

rta

in

re

ve

rsi

bl

e

adverse s

u

b

j

e

c

t

i

v

e

Soil s

i

t

e

s

p

e

c

i

sh

or

t

l

o

w

pr

ob

ab

le

re

ve

rsi

bl

e

adverse s

u

b

j

e

c

t

i

v

e


96


f

i

c L

and

La

nd

use

cha

ng

e

s

i

t

e

s

p

e

c

i

f

i

c

lo

n

g

m

e

d

i

u

m

ce

rta

in

Irr

ev

er

si

bl

e

adverse o

b

j

e

c

t

i

v

e

Co

nst

ruc

tio

n

wa

ste

s

i

t

e

s

p

e

c

i

f

i

c

m

e

di

u

m

l

o

w

ce

rta

in

re

ve

rsi

bl

e

adverse o

b

j

e

c

t

i

v

e

Water bodies s

i

t

e

s

p

e

c

i

f

i

c

S

h

or

t

l

o

w

po

ssi

bl

e

re

ve

rsi

bl

e

adverse s

u

b

j

e

c

t

i

v

e

Bio

logic

al

Flora s

i

t

e

s

p

e

c

i

f

i

c

p

er

m

a

n

e

nt

m

e

d

i

u

m

ce

rta

in

irr

ev

er

si

bl

e

adverse o

b

j

e

c

t

i

v

e

Fauna (terrestrial ) s

i

t

e

s

p

sh

or

t

l

o

w

hi

gh

ly

pr

ob

ab

le

re

ve

rsi

bl

e

adverse s

u

b

j

e

c

t


97


e

c

i

f

i

c

i

v

e

Socio-

economic

Employment l

o

c

a

l

m

e

di

u

m

m

e

d

i

u

m

C

ert

ai

n

- beneficial o

b

j

e

c

t

i

v

e

Oth

ers

Health l

o

c

a

l

m

e

di

u

m

h

i

g

h

po

ssi

bl

e

Pa

rtl

y

R

ev

er

si

bl

e

adverse s

u

b

j

e

c

t

i

v

e

Noise S

i

t

e

s

p

e

c

i

f

i

c

m

e

di

u

m

l

o

w

ce

rta

in

R

ev

er

si

bl

e

adverse o

b

j

e

c

t

i

v

e

Safety (Accidents) L

o

c

a

l

--

--

h

i

g

h

Po

ssi

bl

e

R

ev

er

si

bl

e

adverse s

u

b

j

e

c

t

i

v

e

WTP-Post construction Phase


Spatial

Extent

D

u

r

at

io

n

sig

nif

ica

nc

e

pr

ob

ab

ili

ty

of

oc

cu

rr

Reversibility Adv

erse/

bene

ficial

Objective

/Subjective


98


en

ce

Ph

ysi

cal

Air

Qu

alit

y

site specific sh

or

t

l

o

w

ce

rta

in

re

ve

rsi

bl

e

adve

rse

subje

ctive

Soil site specific sh

or

t

l

o

w

pr

ob

ab

le

re

ve

rsi

bl

e

adve

rse

subje

ctive

Wa

ter

bod

ies

site specific sh

or

t

l

o

w

po

ssi

bl

e

re

ve

rsi

bl

e

adve

rse

subje

ctive

Biological Fau

na

(ter

rest

rial

)

- - - - -

Socio-

economic

Em

plo

ym

ent

local S

h

or

t

l

o

w

C

ert

ai

n

- bene

ficial

objec

tive

Others

Hea

lth

local S

h

or

t

h

i

g

h

po

ssi

bl

e

R

ev

er

si

bl

e

adve

rse

subje

ctive

Noi

se

Site specific S

h

or

t

l

o

w

ce

rta

in

R

ev

er

si

bl

e

adve

rse

objec

tive

Saf

ety-

Acc

ide

nts

Local S

h

or

t

h

i

g

h

Po

ssi

bl

e

R

ev

er

si

bl

e

adve

rse

subje

ctive

WTP-Operation Phase

Physical

Air

Qu

alit

y

site specific lo

n

g

h

i

g

h

ce

rta

in

irr

ev

er

si

bl

e

adverse ob

je

cti

ve

Soil site specific lo

n

g

h

i

g

h

po

ssi

bl

e

re

ve

rsi

bl

e

adverse su

bj

ec

tiv

e

Wa

ter

bod

site specific lo

n

g

h

i

g

po

ssi

bl

re

ve

rsi

adverse su

bj

ec


99


ies h e bl

e

tiv

e

Biological

Fau

na

(ter

rest

rial

)

site specific lo

n

g

l

o

w

im

pr

ob

ab

le

re

ve

rsi

bl

e

adverse su

bj

ec

tiv

e

Socio-

economic

Em

plo

ym

ent

local lo

n

g

l

o

w

C

ert

ai

n

- benefici

al

ob

je

cti

ve

Ha

bita

bilit

y of

Cit

y

City lo

n

g

h

i

g

h

C

ert

ai

n

benefici

al

ob

je

cti

ve

Others

Hea

lth

(ha

zar

d)

site specific sh

or

t

l

o

w

po

ssi

bl

e

R

ev

er

si

bl

e

adverse su

bj

ec

tiv

e

Hea

lth

imp

rov

em

ent

City lo

n

g

h

i

g

h

ce

rta

in

- benefici

al

ob

je

cti

ve

Noi

se

Site specific sh

or

t

l

o

w

ce

rta

in

R

ev

er

si

bl

e

adverse ob

je

cti

ve

safe

ty

(Accidents)

Site specific --

--

-

h

i

g

h

Po

ssi

bl

e

R

ev

er

si

bl

e

adverse su

bj

ec

tiv

e

Hea

lth

&

safe

ty

(hazard)

Site specific --

--

-

h

i

g

h

po

ssi

bl

e

re

ve

rsi

bl

e

adverse su

bj

ec

tiv

e

WTP-Decommissioning Phase

Physical

Air Quality site

speci

fic

sh

or

t

l

o

w

po

ssi

bl

e

re

ve

rsi

bl

e

adverse su

bj

ec

tiv

e

Soil site

speci

fic

sh

or

t

m

e

d

i

u

m

po

ssi

bl

e

re

ve

rsi

bl

e

adverse su

bj

ec

tiv

e

Water bodies site sh m po re adverse su


100


Table 6.4 Check List of Potential Environmental Impacts Downstream of the Wastewater Treatment Plant


Spati

al

Exten

t

Dur

ation


occurrence

Reversibil

ity

Adverse/

beneficial

Objective

/Subjective

Downstream of the Wastewater Treatment Plant-Operation Phase

Ph

ysi

cal

Air Quality Local lo

ng

high ce

rta

in

-

-

-

-

-

b

e

n

e

f

i

c

i

a

l

o

bj

ec

ti

ve

Soil Local lo

ng

high po

ssi

bl

e

-

-

-

-

b

e

n

e

f

i

c

i

a

l

o

bj

ec

ti

ve

Water

bodies

(better quality

effluent)

Local lo

ng

high ce

rta

in

-

-

-

b

e

n

e

f

i

o

bj

ec

ti

ve

speci

fic

or

t

e

d

i

u

m

ssi

bl

e

ve

rsi

bl

e

bj

ec

tiv

e

Socio-

economic

Employment

opportunity

local sh

or

t

l

o

w

C

ert

ai

n

- benefici

al

ob

je

cti

ve

Employment

loss

local m

e

di

u

m

h

i

g

h

po

ssi

bl

e

adverse ob

je

cti

ve

Others

Health

(hazard)

Loca

l

sh

or

t

l

o

w

Po

ssi

bl

e

R

ev

er

si

bl

e

Advers

e

Su

bj

ec

tiv

e

Safety/accide

nt

Loca

l

sh

or

t

l

o

w

Po

ssi

bl

e

R

ev

er

si

bl

e

Advers

e

Su

bj

ec

tiv

e


101



Spati

al

Exten

t

Dur

ation


occurrence

Reversibil

ity

Adverse/

beneficial

Objective

/Subjective

c

i

a

l

Ground

water

contaminati

on risk

Local L

on

g

med

ium

po

ssi

bl

e

r

e

v

e

r

s

i

b

l

e

a

d

v

e

r

s

e

su

bj

ec

ti

ve

Bio

logic

al

Flora Local lo

ng

high ce

rta

in

- b

e

n

e

f

i

c

i

a

l

o

bj

ec

ti

ve

Fauna-

terrestrial

Local L

on

g

low po

ssi

bl

e

r

e

v

e

r

s

i

b

l

e

a

d

v

e

r

s

e

su

bj

ec

ti

ve

Socio-

economic

Income

generation

local lo

ng

med

ium

C

ert

ai

n

-

b

e

n

e

f

i

c

i

a

l

su

bj

ec

ti

ve

Habitability Local lo

ng

high C

ert

ai

n

- b

e

n

e

f

i

c

i

a

l

o

bj

ec

ti

ve

Others Health

improveme

nt

City lo

ng

high ce

rta

in

- b

e

n

su

bj

ec


102



Spati

al

Exten

t

Dur

ation


occurrence

Reversibil

ity

Adverse/

beneficial

Objective

/Subjective

e

f

i

c

i

a

l

ti

ve

Downstream of the Wastewater Treatment Plant-Decommissioning Phase

Water bodies contaminati

on

Near

the

site

sh

or

t

low po

ssi

bl

e

r

e

v

e

r

s

i

b

l

e

a

d

v

e

r

s

e

su

bj

ec

ti

ve

Lack of

irrigation

water

local lo

ng

high po

ssi

bl

e

a

d

v

e

r

s

e

su

bj

ec

ti

ve

Socio economic employmen

t

local - - po

ssi

bl

e

- a

d

v

e

r

s

e

su

bj

ec

ti

ve

6.2 Environmental and Social Impacts

The above analysis brings out the impact areas that are of concern for the implementation of the

sub-component. These are discussed in the following paragraphs.

6.2.1 Impacts in Sewer trunk Line Part of the Project

6.2.1.1 Mobilization Phase

The mobilization phase involves construction of guard posts at selected points along the sewer trunk,

availing of excavators, transportation of tools, pipes, construction materials, etc.

Ambient Air Quality

The impact is due to vehicular emission and increase in suspended particles in the air from

movement of heavy machinery and trucks. The sites for the sewer line installation are distributed and

therefore the effect on air quality would be slight and temporary.

Soil


103


There will be little or no impact on soil in this phase.

Water bodies

There will be little or no impact on water bodies in this phase.

Flora and fauna

Improper management and placement of equipment and machineries may bring minor impacts on

vegetation and plantation forest as well as on vegetables like cabbage, pepper and lettuce that are

grown in river bank areas and homestead farmlands. The project activities will affect merely some

remnant or secondary trees, bushes and shrubs, almost all of which are widely distributed in the area

and elsewhere. The impact is insignificant.

Socio-economy

Some unskilled workers will get temporary employment in this phase. There will be property and

business loss, disruption of social relations, etc.

Safety

There may be safety issues like accidents during loading and unloading of pipes and other

construction materials for the workers and local communities. The impacts are possible, adverse, and

of high significance.

Noise and Vibration

There will be noise associated with the vehicular movement.

6.2.1.2 Construction Phase

The communities living along the sewer line may experience disturbance during the construction

phase. However, most part of the sewer line will be laid along roads.

Ambient Air Quality

The impact on air quality comes from dust emission from excavation of trenches and vehicular

emissions. The emissions of air pollutants include airborne particulates (dust), fugitive emissions,

exhaust and combustion emissions. These impacts are temporary, short-term, reversible and adverse

but of low significance on site but negligible off-site.

Soil

Excavated soil will be exposed to erosion. Removal of trees andvegetation, shrub types and

Arundodonax, grown along the riverside for stabilization of river banks will bring soil instability and

erosion.Accidental chemical/oil spill can cause soil contamination. This impact is possible and of

high significance, short duration and reversible.

Water bodies

The effect will be mainly due to siltation caused by erosion of excavated soil. The impact is negative,

temporary, of medium duration and low significance.

Flora


104


Site clearing, excavation works and construction activities will cause loss of vegetation, tree species

and plantation forests that are found along river side, residential houses, institutional compounds and

forest sites. These include indigenous ones like Acacia Abyssinica, Acacia Albida, Cordia Africana,

Dovyalis Abyssinica, Ficusdahro, Ficussur, Olea Africana, Croton Macrostachys, Cupresseslustinca,

Rangiagrandis, Vernoniaamygdalina, etc. Unwise and inappropriate dumping of soils in the forest

sites will also aggravate the loss of forest tree species.Construction components of the project will

have relatively important impacts also on plantation forest. Although this artificial forest area

contains dominantly exotic tree species, in some parts it has a considerable number of indigenous

trees and patches of bush-lands. The impact is of medium significance, permanent, and adverse.

Fauna

The Plantation Forest at “Lafto” sub city area in the West trunk direction of Kaliti WTP and the

patches of natural forest in the plantation forest are habitats for some species of wild animals mainly

hyenas, monkeys, Anubis baboon and Bush duiker, as well as a variety of birdlife. Some wild

animals come and live at the river side using patches of grasses and bushes and shrubs for shelter. A

small portion of these habitats would be affected or disturbed by the construction and installation

activities of the sewer line expansion. The wild animals found in the impact areas would temporarily

move away from the disturbed areas and are likely come back once the disturbance has ceased.

Since most of the wildlife found in the area are those species adapted to disturbed habitats, they are

not expected to be significantly affected by the temporary disturbances and loss of limited habitats.

Therefore, it can be concluded that implementation of the project will not bring any serious impacts

on wildlife, and the potential impacts will be localized and less significant.

Socio-economy

Unskilled and some skilled workers will get temporary employment in this phase This impact is

positive and temporary. The project work can cause temporary disruption to residential area at a

small section of the “Bole Bulbula” sewer. Asphalted roads will be dug at few places where the

sewer line crosses the roads. At such points, there will be temporary disturbance to vehicular and

pedestrian movement. Traffic congestion, lack of parking and loss of access can be seen at some

construction points. Moreover, the impact is considered temporary, major adverse and of short term.

In addition, there will be property losses (houses, farmlands, trees, fences, etc) in some areas. These

losses are permanent and require compensation and resettlement.

Health and Safety

There may be safety accidents like falling into open trenches or open water, trench collapse,

reversing machinery, etc. The impacts are probable, adverse, and of high significance. Dust and

vehicular emissions are probable. These are of medium term and of low significance. Large-scale

construction works mostly have the potential for the spread of HIV/AIDS and other STDs. This risk

is possible and of high significance.

Noise

This nuisance created by vehicles and excavators is transient.

Sensitive Areas


105


There sewer trunk line passes through or crosses the:

Saudi Arabia Embassy

Behere Tsige Park

Mosque (fence)

Ring Road (two times)

Railway line under construction

Cultural Heritage

There are no archeological sites or monuments in the project area that can be affected by the project.

The project will not have interference with the traditions and customs of the people. There are no

graves identified along the proposed sewer line.

Impacts on existing sewer system

The new sewer line is to be installed close to the existing sewer line and may be broken or damaged

accidentally. Although there will be a six meter buffer between the two, there seem to be instances

where the two lines cross each other. In addition, the exact location of the existing sewer line does

not seem to be known. This impact is probable and of high significance.

6.2.1.3 Post Construction Phase

This section deals with the prediction and evaluation of the impacts of sewer lines on the

environment during post-construction phase.

Ambient Air Quality

The impact is due to dust and vehicular emission. It is of short duration and insignificant.

Soil

Littering with construction waste is the main cause of soil contamination. The impact is low,

reversible and of short duration.

Water bodies

The impact will be if litter is washed or leached to water bodies. The impact is low, reversible and of

short duration.

Flora

Liquid and solid wastes generated from construction activities and leftover construction material at

the vegetation and forest land will have minor impact and may reduce survival of the vegetation and

tree species. This effect will be observed on vegetation, indigenous and plantation forest tree species.

The impact is minor, reversible and of medium term.

Socio-economy

Some unskilled workers will get temporary employment in this phase. Few individuals may benefit

from selling food and drink services to the workers.


106


Health

Trench excavations and other earthworks may modify the local topography and drainage system and

create stagnant water points. These water pools may become favorable breeding sites for vector

mosquitoes that transmit malaria to the communities living in the surrounding areas.

Safety

There can be accidents associated with loading and unloading operations and also due to traffic.

These are possible and of high significance. There will also be dust and vehicular emissions.

Noise

The noise pollution in this phase is due to the limited vehicular movement transporting tools, leftover

construction material dismantled guard posts and stores. The impact is of very short duration and

insignificant. It therefore requires no mitigation.

6.2.1.4 Operation Phase

Ambient Air Quality

No negative impact is expected to air quality when the sewer line is in operation. On the contrary, the

air quality will be improved because of a cleaner environment created.

Soil

Soil contamination due to leakage is possible. The impact is long term, of low significance, and

reversible since significant leakage is not expected.

Water bodies

The impact is when leaked sewage is washed by run-off or leaches to underground water. However,

it will be of low significance since leakage amount is not expected to be significant.

Flora and fauna

No impact.

Socio-economy

The city will become cleaner and more habitable. It will avoid visual nuisance.

Health

The project will improve public health and minimize health risk by improving sewerage collection

and treatment. It will avoid odor due to open and uncontrolled release of wastewater from domestic

facilities. The impact is long term and of high significance.

Noise and Vibration

No impact.


107


6.2.1.5 Decommissioning Phase

The activities in this phase includes digging the area surrounding the pipe line, removing of soil and

concrete covers, demolishing manholes, dismantling of the sewer line, backfilling and transportation

of recyclable and reusable (pipes)materials.

Ambient Air Quality

The impact is due to sewage odor, dust, and vehicular emission. The odor effect will be felt more by

the workers.

Soil

Spillage of sewage waste is the main cause of soil contamination.

Water bodies

The impact will be if spillage of sewage is washed or leached to water bodies.

Flora

The impact on flora is assumed insignificant and reversible.

Socio-economy

Some unskilled workers will get temporary employment in this phase.

Health and safety

Minor accidents, dust and other emissions are possible risks to workers. The impacts are of low

significance, adverse, and temporary. In addition, contamination by sewage is possible. This may

cause disease to the workers and the residents nearby. This impact is of high significance.

Noise

The noise pollution is due to the limited vehicular movement transporting tools, dismantled pipes,

etc. The impact is of very short duration and insignificant.

6.2.2 Impacts in the Wastewater Treatment Plant

In general, construction of a new WTP will have a positive environmental impact as well as some

negative impacts. It is expected to produce a long-term improvement in public health, reduce water

pollution (surface and ground) in areas where the sewage drains.


The mobilization phase includes activities like transportation of equipment, machineries, workers

and materials to the waste treatment plant site.

Ambient Air Quality

The causes of pollution of the ambient air can belargelydue to emission from vehicles which

transport machineries, equipment, construction materials and workers to the site. The road to the

plant site is largely asphalted. The generation of dust is therefore minimal along the road. Dust may

be generated inside the treatment plant site as it is not asphalted. However, the compound is covered

with much vegetation. The dust effect would be absorbed by the vegetation. It is reported that the

trees are planted by the office. Currently, about 5,600 m3 of septic and latrine waste per week is


108


transported to the existing plant. This is equivalent to saying that about 80 trucks loaded with such

waste are coming to the site daily. As compared to this number, the number of trucks needed in the

mobilization phase will be very small. Hence, the vehicular emission caused by the mobilization

phase vehicles can be considered as negligible when compared to the daily vehicular emission

caused by trucks transporting septic waste to the site. Moreover, the vehicular emission depends,

among others, on the age of vehicles, the retrofit exhaust technologies and their maintenance. The

effect is reversible, and of short duration and therefore the impact is insignificant.

Soil

The expected new plant site is within the old/existing site. There may be some soil contamination

due to oil leaks from vehicles and machineries as well as due to some unhygienic practices.

However, the area is small and the mobilization phase is relatively short. The impact will be very

small and of very low significance.

Water bodies

There will be no impact on water bodies.

Flora

Dust generated by the movement of vehicles will deposit on nearby vegetations. There will be little

or no removal of vegetation within the plant site. This impact is low, reversible and of short duration.

Fauna

The compound is large and the area intended for the new plant is very close to the existing one. The

few wild animals in the compound live far from this area and should not be impacted.

Socio-economy

Some unskilled workers will get temporary employment in this phase. Many of the workers can be

obtained locally.

Health and Safety

There might be accidents of various natures to the workers. The impacts are of high significance.

Dust and other emissions may affect the respiratory tract. The impacts are possible and of low

significance.

Noise and Vibration

There will be noise and very little vibration associated with the vehicular movement. However, the

intensity is very low and the traffic flow is expected to be isolated.

Traffic

The current access route for vacuum trucks transporting septage waste to the drying beds may not be

available. This impact is of high significance.


109



In this section, the assessment of the impacts during the construction of the WTPis presented.

Ambient Air Quality

The emission sources in the construction phase include:

Site clearance

Excavation and other earth works

Dust emissions from handling and transportation of excavated material, construction inputs and

auxiliary materials, and

Gaseous emissions from vehicles and construction equipment

Cutting and welding operations

odor

However, the dust generation is expected to be of low volume and intensity. The composition of dust

is often inorganic and of non-toxic nature. The vehicular emissions constitute such gaseous

pollutants as oxides of nitrogen, sulfur dioxide, carbon monoxide, CO2, some unburned

hydrocarbons. The effect will be restricted to the plant site and especially to the workers. The

potential effects are influenced by the weather conditions (rain and wind direction) and by preventive

measures implemented during construction to minimize emissions. The impact significance can be

rated low, direct, short-term, adverse, and reversible.

Soil

The new plant site is expected to be built within the old/existing site. The activities that affect soil in

the construction phase include site clearing, stripping of top soil, excavation and other earth works,

loading and hauling and machinery maintenance

Excavation and site clearing make the soil lose its natural cover. This will increase the risk of soil

erosion and silt runoff into watercourses temporarily, in particular for the construction of the ponds,

landfill sites, installation of sewer line. In addition, hauled material, if not kept properly, may be

exposed to erosion. Top soil will also be exposed to wind erosion (dust generation) during haulage

and movement of other vehicles. Soil erosion can be strong if the excavation activities are carried out

during the rainy season.

Solid waste generated during site preparation and construction work would include cut vegetation

and typical construction waste like wasted concrete, steel, wooden scaffolding and forms, bags,

waste earth materials, etc. Solid waste and leakage and improper handling of fuel, lubricants and oil

especially during maintenance of machinery can contaminate the soil. However, the area is small and

the site clearing and excavation works are expected to last for a short period. The impact is highly

probable although it is site specific. Therefore, the impacts as a result of the activities in this phase

will be direct, adverse, reversible, temporary and of low significance and medium term.

Land

Currently, the area outside of the existing WTP is covered with trees and shrubs planted by AAWSA.

The construction of the new treatment plant necessitates clearing of some of this vegetation. Thus,

because of the erection of infrastructures, the land will permanently lose its original functions and a

considerable amount of the land will become impermeable to water. The surface runoff will increase


110


and with it soil erosion. However, the total area that would be impacted is estimated to be about

18,100m2 which is not large. This impact is, therefore, rated medium but permanent.

Water bodies

Construction works within or adjacent to watercourses have the potential for reducing water quality

through increased sediment load. Fuel leakages from storage tanks or vehicles and inappropriate

disposal of wastes can cause pollution incidents. Such material can also be leached to the

groundwater. The impact is low, short term, adverse, temporary and reversible.

Flora

Dust generated by the movement of vehicles will deposit on nearby vegetation. This impact is

insignificant.

There is need for space for the new plant. Thus, clearing of the land, excavation work and

construction activities will cause a general loss of vegetation and tree species that are found in Kaliti

WTP compound. Some of the tree species include indigenous ones like Acacia abyssinica (Girar),

Acacia albida, Cordiaafricana (Wanza), Dovyalisabyssinica, Ficusdahro, Ficussur, Olea Africana,

Croton macrostachys, Cupresseslustinca, Rangiagrandis, Vernoniaamygdalina, etc.

Fauna

There are few bird species living on some of the trees and on facultative ponds of the treatment plant.

These may be disturbed during construction activities because of the noise created by heavy

machinery and equipments. The wild animals found in the impact areas would temporarily move

away from the disturbed areas and are likely to come back once the disturbance has ceased.

Therefore, implementation of the project will not bring any serious impact on wildlife, and the

potential impacts will be localized and less significant.

Socio-economy

There are large positive impacts on the social environmental elements. These include improved water

supply of the downstream populated areas due to good quality of the groundwater, and improved

health of the downstream population as a result of the improved quality of drinking water.No new

area will be reclaimed and no communities will be displaced since the new treatment plant will be

installed in the same compound. Both skilled and unskilled workers will get temporary employment

in this phase. Few individuals in the area may benefit from selling food and drink services to the

workers. The impact is positive and temporary of medium significance and medium term.

Health and safety

Large-scale construction works mostly have the potential for the spread of HIV/AIDS and other

STDs. The risk is high, possible, of medium duration, and partly reversible.

Borrow pits and other construction related activities may create stagnant water that can become

breeding place for diseases. This impact is negative, temporary, short term and minor. There might


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be accidents of various natures to the workers. The impacts are high. Dust and other emissions may

affect the respiratory tract.

Noise and vibration

Noise will be generated due to activities of loading-unloading, material handling, machine operation,

equipment & vehicular movement. Small but temporary degree of vibration may be felt during

compaction and movement of heavy vehicles. Impact of noise and vibration may be categorized as

direct, short-term, adverse, reversible and of low -magnitude.

Traffic

There will be traffic congestion/inconvenience at and near the entrance to the WTP due to increased

number of vehicles and workers. Moreover, the impact is considered temporary, major adverse and

of short term.


The activities in this phase generally include dismantling of equipment and shades (if any) used in

the construction phase, transportation of equipment and tools. During these activities, the area may

be littered with packaging materials, broken items, used items that may not be retained useful by the

contractor and leftover materials. There may also be spillage of oil, fuel and grease.

Ambient Air Quality

Dust will be generated by the movement of vehicles. The air quality within the compound will be

affected by dust and vehicular emission. However, the magnitude will be much lower than in the

previous two phases. The impact will be transient and will be restricted to the plant site. Therefore,

the impact is considered reversible, direct, temporary and of very low significance.

Soil

The impact on soil is mainly contamination due to littering. There can also be wind erosion because

of dust creation. This impact is of very short time, reversible, adverse and of very low significance.

Water bodies

Leaching and washing of litter, spilt oil, fuel, etc may affect water bodies. However, this impact is

low because of the short duration of the phase and the limited activities to be carried out. It is direct,

reversible, adverse, temporary and of low significance.

Flora

None of the activities in this phase requires vegetation clearing. Already trucks loaded with sewage

waste travel to the site intensively. Any possible impact on flora due to dust caused by the vehicular

movement in this phase will be irrelevant. The impact is negligible.

Socio-economy

Both skilled and unskilled workers will get temporary employment in this phase.

Health


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Excavation and earthworks may modify the local topography and drainage system and create

stagnant water points. These water pools may become favorable breeding sites for vector mosquitoes

that transmit malaria to the communities living in the surrounding areas.

Safety

There can be different accidents during loading and unloading, and also traffic accidents. These are

possible and of high significance. There will also be dust and other emissions. The impacts are of

low significance, adverse, and temporary.

Noise

The noise pollution in this phase is due to the limited vehicular movement transporting equipment,

tools, etc from the plant site. Since the volume of such material to be transported is low as compared

to that in the mobilization phase, the impact will be insignificant and requires no mitigation.


The major activities in this phase are collection, treatment and post treatment of sewage waste. Detail

activities include measurement and control of flow; water level control in ponds; quality control of

effluent, maintenance and repair of units, de-sludging and drying of sludge and disposal of sludge to

landfill site.

Ambient Air Quality

Odors can be generated and released from virtually all phases of wastewater collection, treatment,

and disposal. The potential for the initial release or later development of odors begins at the point of

wastewater discharge from homes and industries. It continues with collection and movement of

wastewater in gravity sewers, ending with the actual wastewater treatment and solids handling and

disposal at the plant or disposal site.

The proposed WTP may generate odor, mainly due to:

Septage Receiving Station –Significant odor is generated at this step.

Screenings if piled onsite and intermittently buried or trucked offsite.

Grit Removal Chambers – If the grit from this process are piled onsite, and intermittently

buried or trucked off site.

Trickling filter– Due to the maintenance issues

Anaerobic digesters – Anaerobic digestion causes the release of hydrogen sulfide,

Sludge handling systems

When the above factors combine, significant odor can be generated at the proposed WTP. Hydrogen

sulfide gas, a major odor source in wastewater treatment systems, results from septic (anaerobic)

conditions in the wastewater or solids. Metallic sulfide compounds in the wastewater produce a black

color, indicating the presence of dissolved sulfide. Ammonia and organic odors are also common.

Odors from wastewater and its residuals become significantly more intense and develop much higher

concentrations of odorous compounds when the oxygen in the waste is consumed and anaerobic

conditions develop. Anaerobic conditions can develop in sewer systems upstream of the wastewater

treatment plant as well as unit processes such as primary clarifiers, UASB reactors trickling filters,


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sludge digesters and sludge storage in which anaerobic conditions are likely to develop. Odors may

initially develop and later become worse due to poor design, such as insufficient ventilation or

excessive turbulence.

Other emissions come from pumping station operations, vehicles, and from the operation of standby

diesel generator during power failures. The emissions from the diesel generator will have marginal

impact on the existing air quality. The impact is of long term, adverse, irreversible and of high

significance for long exposure.

Soil

In general, the soil in the treatment plant site should not be affected since the treatment is supposed

to be carried inside waterproof and properly designed units. However, in case of spillages and

overflows, the risk will be high. This impact is high, long term, reversible, rare and adverse.

Operation of the wastewater treatment system generates large quantities of sludge. Sludge with

hazardous substances disposed at the temporary storage can provoke large negative impact

contaminating soil and consequently water.

Water bodies

The waste is treated inside properly designed units. Neither the sludge nor the drained water will be

allowed to leave the plant without proper treatment. However, if there is leakage or overflow, the

contamination risk will be high, reversible, short range.

The heavy metals in the treated wastewater may have potential human and environmental health

impacts. The proposed treatment plant will have the capability to retain significant amount of such

contaminants, but they can just transfer from the liquid phase in the solid phase (sludge) in case of

primary and secondary treatment and/or into aquatic plants in case of tertiary treatment (constructed

wetland). This will prohibit the use of sludge as a fertilizer.

Considering the situation in Addis Ababa, contaminations from petrochemical origin are ubiquitous

from activities such as fuel stations, garages and workshops, industries and various other activities. It

is anticipated that most of the high molecular and non-polar petrochemicals can be efficiently

retained in the proposed WTP. However, as some of them are persistent to both aerobic and

anaerobic biodegradation processes in the UASB and Trickling Filters, they can easily be

accumulated in the sludge. This will prohibit the potential use of the large amount of sludge as a

fertilizer. The impacts are possible, reversible, of high significance and long term.

Fauna

If improperly treated wastewater is released to the facultative ponds and drying beds, it may affect

bird species living on the beds through contaminants production and reduce the necessary nutrients

available for their growth and development due to eutrophication and hence birds’ variety and

number will reduce. Bird’s species of ducks, animals living in the surrounding of the treatment plant

like horses, cows and oxen may be affected from the discharge of improperly treated wastewater and

sludge production from the treatment plant. This problem is improbable, of low significance and of

long-term duration in the sense that the risk is always there, but reversible.

Socio-economy


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Both skilled and unskilled workers will get temporary and permanent employment for the operation

of the plant. Small businesses may emerge around the plant. Increase in the number of people and

industries to be served by sewer network, use of flush toilets instead of pit latrine thereby reducing

the risk of ground water pollution

It will avoid odor and visual nuisance due to open and uncontrolled release of wastewater from

domestic and industrial facilities.

There are large positive impacts on the Social Environment elements: improved water supply of the

downstream populated areas due to good quality of the groundwater, and improved health of the

downstream population as a result of the improved quality of drinking water.

Health

It enhances the existing environment, as the untreated raw sewage disposal will be ceased. It will

also improve treatment of sludge collection from septic tank through provided facilities by the

project that will make possible to accept sludge in its sewer via sludge injection points.

However, there is potential significant public health hazard problem that is related with spills,

leakage, and discharge of sewage or uncontrolled spreading of sludge. The impact is adverse,

possible, reversible, of high significance and long-term.

Safety

Hydrogen sulfide is a colorless, toxic gas with a characteristic rotten egg odor. It is considered a

broad-spectrum poison, meaning it can poison several different systems in the body. Breathing very

high levels of hydrogen sulfide can cause death within just a few breaths. Loss of consciousness can

result after fewer than three breaths. Exposure to lower concentrations can result in eye irritation, a

sore throat and cough, shortness of breath, and fluid in the lungs. Long-term, low-level exposure may

result in fatigue, loss of appetite, headaches, irritability, poor memory, and dizziness. The OSHA

permissible exposure limits for hydrogen sulfide are 10 ppm (time-weighted average) and 15 ppm

(short-term exposure limit).

Other potential health and safety impacts include accidents and plant malfunctions. The probability

and impact of the following events were categorized;

• Spills

• Process Upset

• Natural Hazards

• Power Failures

• Fires

• Injury/Death

Noise and vibration

The main sources of noise during the operations phase would include pumping station, diesel

generators, flaring, and vehicle traffic.


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The activities in this phase include dismantling of equipment and metallic structure, demolishing of

concrete structure and transportation of recyclable and reusable materials.

Ambient Air Quality

The impact is due to sewage odor, dust, and vehicular emission. It is of short duration and of low

significance. The odor effect will be felt more by the workers.

Soil and Water bodies

Spillage of sewage waste or contaminated water, sludge, chemicals, oil, etc. is the main cause of soil

contamination. The effect is of medium significance, short term, and reversible.

Flora

There will be little or no impact on vegetation.

Socio-economy

Some unskilled workers will get temporary employment in this phase. Other workers may also lose

job when the plant is not functioning any more.

Health and safety

Minor accidents, dust and other emissions are possible risks to workers. The impacts are of low

significance, adverse, and temporary. In addition, contamination by sewage is possible. This may

cause disease to the workers and the residents nearby. This impact is of high significance.

Noise

The noise pollution in this phase is due to the limited vehicular movement transporting tools,

dismantled pipes, etc. The impact is of very short duration and insignificant.

6.2.3 Impacts Downstream of the WTP


There will be no adverse/beneficial effect on the air, soil, water, land, noise level in the downstream

area as well as on the health and socio-economy of the inhabitants in the area in this phase.








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Ambient Air Quality

The ambient air quality will be improved due to the better sewage treatment. The impact will be for

long term, high significance.

Soil

The soil downstream of the WTP should not be affected by the plant operation directly. However, its

fertility will be increased if the farmers use the (dried) sludge.

Water bodies

There may be contamination of the river due to run off, overflow and leakage from units due to

operation and maintenance failure or other unprecedented environmental calamities. This impact is

improbable and considered high.

During operation of the WTP, there is a possibility for pollution of the groundwater due to leakages

of the system for sewage treatment and effluent production, leakages of the system from sludge

production. These impacts are assessed as negative with moderate in magnitude.

Also, during the drying process of the sludge on the drying beds, there is high possibility for

pollution of the groundwater due to infiltration of leachate from drying beds. As the drying beds are

covering large area, the possible negative impact is assessed as major affecting wider area, actually

wider groundwater aquifer.

On the other hand, operation of the WTP will have major positive impact on the quality of the

groundwater, as there will be no direct discharges of wastewater into the Little Akaki River and its

tributaries. The pollution of the groundwater in project area is mainly due to polluted wastewater

through strong connection with the groundwater and leakages of the existing collectors of

wastewater.

Concerning Surface water including the bottom sediment, the major positive impact from the

operation of the WTP is the improved water quality of the Akaki River, on larger area (within the

project area and downstream of the Akaki River Catchment). It should be noted that the Akaki River

will be at more polluted state than the treated wastewater effluent at least for some time in the future.

Therefore, discharge of treated wastewater from the new WTP will play key positive role in diluting

the otherwise contaminated River water.

A major positive impact from the Kaliti Wastewater Collection and Treatment Plant Project is the

improvement in surface water quality in the catchment, as a result of the untreated wastewater being

properly collected and treated at the new WTP. Cleaning up the waterways in the catchment area will

result in a habitat improvement for aquatic species, improved public health and decrease in

waterborne illnesses for humans, and overall improvement in the quality of life.

Considering the Hydrology of the Akaki River, so far as the wastewater is discharged directly into

the River, it will increase the flows of the river. With collection of the wastewater by the main


117


collectors, the quantity of the river flows shall be controlled and decreased up to the location of the

WTP. However, at location downstream of the WTP, there will be controlled flow of the Akaki

River if the treated water is discharged into the River. Thus, downstream of the WTP there will be

increase of the river flows due to discharged treated wastewater, which is assessed as positive

impact, with low magnitude.

If the treated water is diverted in a pipe for use in irrigation at some other locations, the river

discharge will be decreased. This is considered as negative impact on the hydrology of the River.

In order to mitigate the impact of using the treated water, it is recommended to use part of the treated

wastewater for irrigation.

One of the potential use of the treated wastewater is for irrigation as long as the quality of the treated

water meets the requirement. The FAO treated wastewater quality requirement for irrigation is

shown in Annex 4 The client has conducted a feasibility study on the potential of wastewater from

Kaliti treatment plant for irrigationuse. The consultant has reviewed the design document of the

study made on wastewater reuse for irrigation downstream of the treatment plant along the Banks of

the Little Akaki River and in the Akaki well field area.

As revealed from field observations, the current situation is quite different from what is indicated in

the irrigation feasibility document. Most of the designated commanded areas are full of settlements

except little area along the left Bank of the Little Akaki River (Figure 3.11D).

This small area is currently being irrigated by using water from the highly polluted Little Akaki river

to grow different types of vegetables. Certainly, the treated wastewater that will be available with

this project will be much better than the river water for irrigation and may be used in this small area.

However, this area is too small to absorb all the treated water for irrigation. Therefore, unless the

treated wastewater is taken far downstream into the Oromia Regional State, the irrigable land is very

limited.

The use of treated wastewater for irrigating the Akaki well field has to be seen with caution. Most of

the wells in the Akaki well field are unconfined and semi-confined. This has been illustrated clearly

from previous studies (Tenalem Ayenew et al., 2008). As the wastewater treatment technology may

not be efficient enough to treat trace elements and heavy metals, there is the possibility of polluting

the well field. This issue demands further study on aquifer characteristics and groundwater and

surface water interactions in the area. Therefore, it is not prudent to use the water for irrigation in the

Akaki well field.

Flora and Fauna

Trees can be planted near the site and along the river. They can grow well as they have access to

water. The impact is positive.


118


On the other hand, if removed gritis not buried properly, it may attract birds, rats, dogs, hyena and

various insects. Increased number of insects and wild animals may indirectly lead to adverse impacts

to local people residing around the project area. This impact is low, reversible and of long duration.

Socio-economy

The WTP development will provide water of a quality for irrigation to the downstream area. The

sludge can also serve as soil fertilizer. This will help for income generation. The impact is long term,

beneficial and of high significance.

Health

The water quality of Little Akaki River will improve since treated water complying with the standard

will be discharged to the river contributing to the betterment of the health situation to the inhabitants

downstream of the WTP. Health problems associated with the use of contaminated water will

improve. The impact is highly beneficial since vegetables grown using the newly treated wastewater

and sludge will be healthier when consumed. The effect is city-wide.

Noise and vibration

There will be no noise impact.


In this section, the impact on the downstream society and environment when the WTP is being

decommissioned will be analyzed.

Ambient Air Quality

The sewage odor, dust, and vehicular emission that will be created in the WTP site will not have

perceptible effect on the downstream area. In addition, the period is relatively short.

Soil

There will be little or no impact.

Water bodies

The impact will be due to spillage of the materials mentioned in the above section, which can be

washed or leached to water bodies. It will be very low, of short term and reversible. Reduction/lack

of irrigation water is another impact.

Flora


Socio-economy


119


The impacts are reduction/lack of irrigation water and loss of employment.

Health and safety


Noise


Table 6.5Summary of Important Negative Impacts

Receptor

Impact Type Phases

Objective Subjective

Mo

bil

ize.

Co

nst

r.

Deco

m.

Op

era

t

Sewer trunk Part of the Project

Soil excavation/trenching M3-

M

Flora

site clearing P-M

vegetation removal M-

M

water soil erosion/siltation-

excavation/trenching

M-

L

Socio-

economy

Property loss P-H P-H

Health and

Safety

Accidents loading and unloading operations,

reversing machinery, falling from culverts,

in trenches,

H H H

STD, HIV/AIDS H

Others

Saudi Arabia Embassy S-H

Behere Tsige Park M-

M

Mosque (fence) S-H

Existing sewer system M-

H


Air Quality

Odor from septage receiving station, grit

removal chambers, trickling filter, anaerobic

digesters, sludge handling systems, etc.

- - H

Soil/land

sewage overflow - - - H

Unsafe sludge disposal - - - H

loss of original function - P-

M

- -

3 1

st M:Medium duration, 2

nd M:Medium Significance, P:Permanent, H: High Significance, S:Short duration, L: Long

duration


120


Receptor

Impact Type Phases


Mo

bil

ize.

Co

nst

r.

Deco

m.

Op

era

t

Water


Unsafe sludge disposal - - - H

Flora vegetation removal x P-

M

- -

Health and

Safety

Accidents H H H H

STD, HIV/AIDS - M-

H

-

Health risk - - H


water

inappropriate waste disposal

Unlined drying beds

- - - H


Table 6.6Summary of Important Positive Impacts

Receptor

Impact Type Phases


Mo

bil

izati

on

Co

nst

ructi

on

Deco

mm

iss.

Op

era

tio

n

Sewer trunk Line Part of the Project

Water

Reduction of

contamination of surface

and ground water

L-

H

Soil Reduction of

contamination of soil

L-

H

Socio-economy

Employment M-M

Improved habitability of the

City

L-H

improved public health - - - L-H


Water Reduction of contamination

of surface and ground water

L-H

Soil Reduction of contamination

of soil

L-H

Socio-economy Employment x M-M x


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Receptor

Impact Type Phases


Mo

bil

izati

on

Co

nst

ructi

on

Deco

mm

iss.

Op

era

tio

n

Improved habitability of the

City

L-H

improved public health - - - L-H


Air quality improved air quality - - - L-H

Soil/land improved fertility - - - L-H

Water

surface/underground

improved water quality of

Little Akaki

- - - L-H

Flora

more vegetation due to increased

fertility and availability of cleaner

water, healthier vegetables

- - - L-H

Socio-economy

more income due to improved

farming

- - - M

cleaner environment - - - L-H

Health and Safety improved public health - - - L-H

6.3 Mitigation Measures

6.3.1 Mitigation Measures in the Sewer trunks Line Part


Ambient Air Quality

The impact can be mitigated by avoiding equipment and vehicles left running unnecessarily, using

protective wear and spraying water on dusty work areas.

Flora and fauna

The impact can be mitigated by awareness creation to the workers and by building soft

communication between the residents and workers through District administration and by

encouraging residents to collect their vegetables before the project activities.

Socio-economy

In order to avoid impacts on socio economic environment of project area rehabilitation and RAP has

been prepared. The PAPs should given employment priority in the project. This plan provides details

on compensation package to project affected families.

Safety

The impact can be mitigated by providing protective wear to workers, following safety procedures

and isolating the work areas.


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Ambient Air Quality

The impact can be mitigated by:

• Efficient scheduling of deliveries to reduce traffic load

• Employing well maintained and operated equipments, using appropriate fuel mixtures,

• Using environmentally friendly equipment with higher fuel efficiency or equipped with air pollution

control devices

• Avoiding equipment and vehicles idle running;

• Sprayingwater on dusty work areas.

• Maintaining stockpiles at minimum heights and forming long-term stockpiles into the optimum shape

(i.e. stabilization)

• Maintaining handling areas in a dust free state as far as practicable.

• Establishing and enforcing appropriate speed limits over all unpaved surfaces.


The mitigation measures are cleaning up spills with an absorbent material, in unstable areas

constructing retaining walls or barriers to avoid land collapse and damage to built-ups before

excavation, covering trenches as soon as possible, collecting excess excavated soil and dumping in

pre-planned sites following appropriate environmental management practices and replanting.

Flora

The impact can be reduced by:

• restricting clearing of vegetation and removal of trees to the imperative area needed

• wherever technically feasible, by preserving indigenous trees found within the impact zone

• implementing a replanting program including indigenous trees

Fauna

Most of the mitigation measures proposed for the impacts on vegetation will also help to mitigate

potential impacts on wildlife. Additional mitigation measures include backfilling of trenches and

other excavated areas and grading to the natural topography as soon as works are completed to avoid

the danger of animal trapping in such holes and to avoid obstruction to animal movements. Poaching

of wildlife by the workforce and deliberate killing of wild animals should be avoided. In order to

realize this measure, training or awareness creation program shall be given for the project personnel

prior to the commencement of the construction works.

Socio-economy

These impacts can be mitigated to some extent through liaison with local communities, good site

management, and maintaining access during installation of the sewer line, utilizing trenchless

technology in high traffic roadways, provision of access to all businesses and properties, restrictions

on construction hours, and limits on the amount of construction that can occur at any one location at

one time.


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Health and Safety

Mitigation measures include providing protective wear to workers, following safety procedures,

isolating the work areas and introducing a traffic plan with speed and traffic regulation through the

neighboring areas and awareness creation on HIV/AIDS.

Sensitive Areas

There sewer trunk line passes through or crosses the:

Saudi Arabia Embassy

Behere Tsige Park

Mosque (fence)

Ring Road (two times)

Railway line under construction (once)

The impact on the Saudi Arabia Embassy and the mosque may be mitigated by negotiation at high level

and if that is not possible by changing the route at these points. The impact on the ring road/railway line

can be mitigated by using micro-tunneling

Existing sewer line

This impact can be skewed by first discovering the existing sewer line.


Ambient Air Quality

The impact can be mitigated by avoiding equipment and vehicles left running unnecessarily and

spraying water on dusty work areas.

Soil, Water bodies and Flora

The effect can be avoided by awareness creation, proper waste disposal and immediate cleaning of

the area.

Health

Pipeline trenches and other excavated places should be refilled and graded to the surrounding

topography immediately following completion of works in order to avoid formation of water

points/pools that may become breeding sites for disease vectors. In case pools are formed, they

should be drained as quickly as possible before they become ideal breeding places for disease

vectors. As preventive measures, construction workers must be informed through awareness rising

and education programs about HIV/AIDS and other SIDs.

Safety

Providing protective wear to workers, awareness creation on safety issues will help to mitigate the

problems.



Joining pipes and fittings as per standard methods, strictly implementing the design slope so as to

ensure the flow of sewage inside the pipes and testing the sewer lines before they are covered with

soil can be used for mitigation.


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Ambient Air Quality

With the use of protective wear, the impact will be minimized.

Soiland Water bodies

The impact can be mitigated by proper site management.

Health and safety

Using protective wearing, avoiding spillage of sewage, following environmental management plans

will mitigate the problem.

6.3.2 Mitigation Measures for the Impacts of the Wastewater Plant


Ambient Air Quality

The impact can be mitigated by avoiding equipment and vehicles left running unnecessarily and

spraying water on dusty work areas.

Soil

Providing toilet services to workers, restricting maintenance in workshops and using modern

vehicles can be used for mitigation.

Flora

Water spraying and proper site management are suggested for mitigation.

Health and Safety

Providing protective wear to workers, erecting traffic signs in the WTP site, giving orientation to

workers about safety procedures and availing first aid services will mitigate the impact.

Traffic

Providing alternative routes to the drying beds will mitigate the problem.


Ambient Air Quality

The potential effects can be mitigated by:

• Performing vehicle inspections and maintain equipment

• Water spraying dusty work areas and roads

• Minimizing disturbed areas

• backfill exposed construction site as soon as possible

• Limiting stockpile height of topsoil below 2m

Soil

The impacts would be mitigated by limiting the excavation and installation of pipelines as much as

possible to the dry season, protecting exposed areas prone to erosion during heavy rain, putting silt

traps in watercourses, re-vegetating exposed areas as quickly as possible, employing modern and

properly maintained vehicles and machineries, handling fuels and oils carefully and responsibly,


125


providing toilet services for workers, construction sequencing, locating stockpiles away from

watercourses, and disposing grit, screenings and sludge from existing lagoons in landfill.

Land

No mitigation.

Water bodies

The impacts can be avoided through good site management and taking pollution prevention

measures. These include locating storage areas and compounds away from watercourses, appropriate

storage of fuel and materials, providing suitable facilities for workers, disposing of waste according

to a waste management plan.

Flora

The impacts can be reduced by:

• restricting clearing of vegetation and removal of trees to the imperative area needed

• wherever technically feasible, by preserving indigenous trees found within the impact zone

• implementing a replanting program including indigenous trees

Health and safety

Mitigation measures include providing protective wear to workers, water spraying dusty work areas,

isolating the work areas and introducing a traffic plan with speed and traffic regulation through the

neighboring areas and awareness creation on safety procedures and HIV/AIDS and availing

healthcare services.

Noise and vibration

Providing workers with noise protective material, limiting construction to daytime hours,

programmed maintenance of vehicles and equipment and using low-noise equipment and machinery

can help to mitigate the problem.

Traffic

These impacts can be mitigated to some extent through liaison with local communities and with good

construction sequencing.


Ambient Air Quality

Water sprinkling, using modern vehicles and introducing speed limits will mitigate the problem.

Soil

Careful dismantling of equipment to avoid any spillage, water spraying and introducing speed limit

to suppress dust and cleaning the area immediately will mitigate the impact.

Water bodies

Immediate cleaning controlled dismantling and properly disposing waste will help to mitigate the

impacts.


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Health

Backfill excavated places, grade to the surrounding topography and drain pools as quickly as

possible.

Safety

Providing protective wear to workers and following safety procedures will help to mitigate the

problems.


Ambient Air Quality

Operating equipment at optimum/design conditions, housekeeping procedures (regular cleaning of

the grit and screenings), facility maintenance, operational practices including process control and

chemical treatment, continuous process of the operation, operating especially the UASB at optimum

condition, planting shrubs and trees along the periphery and providing adequate stack height to

exhaust emissions of diesel generators will help in mitigating the odor and air pollution problems.

Soil

The proposed mitigation measures comprise application of good waste management practices and

disposal at landfill. It is also of crucial importance to dispose the sludge with dangerous substances

in sanitary landfill.

Water bodies

If dried sludge contains heavy metals and poly-nuclear aromatic hydrocarbons, it should be properly

disposed in a sanitary landfill with provision sufficient protection of groundwater contamination.

Connection of untreated/substandard industrial wastewater to the sewer line must be strictly

prohibited. Adequate care should be taken to avoid leakages in the plant. All pipe work and fittings

should be a class rating in excess of the maximum pressure attained in service including any surge

pressure.

Fauna

The mitigation measure is proper quality control of “treated” wastewater and sludge before releasing.

Health

It could be mitigated through provision of buffer zones between the plant and the rest, proper

planning of the project operation and maintenance, proper implementation of the Environmental

Management Plan.

Safety

Adherence to national rules and regulations and to appropriate contact specifications and guidelines,

adopting confined-space entry procedures can be used for mitigation.

Noise

Noise problems can be reduced to normally acceptable levels by incorporating low-noise equipment

in the design and/or locating such mechanical equipment in properly acoustically lined buildings or

enclosures.


127



Ambient Air Quality

The impact can be mitigated by using protective wear.


The mitigation measure is proper site management.

Health and safety

Using protective wearing, avoiding spillage of sewage, following good site management plans will

mitigate the problem.

6.3.3 Mitigation Measures for the Impacts Downstream of the Wastewater Plant


Water bodies

Proposed mitigation measures:

• The whole treatment should avoid leakages of wastewater to groundwater

• Sludge drying beds should be impermeable

• Efficient drainage system for leachate and flood protection structures must be constructed

• temporary sludge disposal sites should be impermeable and protected from flood

• Only partly divert treated water for irrigation use not to significantly reduce the discharge into the

Little Akaki River

Flora and fauna

Grit should be buried regularly in earth. Proper fencing should keep larger animals out of the

WTP compound.


Water bodies

Spillage can be minimized by good site management will avoid the impact. Reduction/lack of

irrigation water can be skewed by putting in place another treatment plant before the

decommissioning of this one.

6.1.1 Concluding Remarks

The proposed activity will not result in any significant negative impact to the Environment that could

not be mitigated. All the identified negative impacts can be mitigated following the Environment and

Social Management Plan. On the other hand, it is envisaged that the project would bring about a

number of important beneficial impacts.


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7 STAKEHOLDERS ANALYSIS

7.1 General

The constitution of Ethiopia in its Article 43 and the Environmental Policy require the need to

consult the interested and affected parties in the planning and implementation of development

projects. Financial Institutions like the World Bank also require different consultations to be made

with concerned public and stakeholders.

Accordingly, different consultations have been conducted with the key stakeholders including the

PAPs in order to:

Inform them about the wastewater line and treatment plant extension and rehabilitation project.

Identify the major existing socio-economic problems of the project area with particular focus on loss

of property and related effects on the biophysical environment

Assess their perceptions and attitudes towards the proposed project

Identify the potential economic and social impacts of the project.

Find out possible mitigation measures that would help to avoid and/or minimize the major negative

impacts and to enhance the positive impacts.

In this section a summarized stakeholder analysis is given. The socioeconomic profile of the project

area is presented in Chapter 4.The stakeholder analysis is part of the socioeconomic surveying and

RAP assessment.

7.2 Scope of the Socioeconomic Study

The study of the socio-economic impact of the proposed project particularly during the construction

and operation phases and proposal of acceptable mitigation measures is the most important

component of the ESIA study. The scope of the work includes identification of permanent or

temporary socio-economic impacts that would be created by the project in different localities at

different stages of the project and the preparation of Resettlement Action Plan (RAP) for those who

are directly affected by the project activity mainly in terms of displacement and property

damage/loss. A detailed account of the socio-economic aspect of this project is presented in the RAP

report (Volume II).

7.3 Approach and Methodology

The main approaches followed for the socio-economic impact assessment and RAP preparation are

the following:

a) Secondary Data Collection and Review

Basic socioeconomic data was collected from the different Districts after identifying the areas to be

affected directly and indirectly by the project.


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In addition, legal and policy frameworks and pertinent institutional aspects are evaluated. These are

presented in Chapter 2. Furthermore, additional documents indicating best practices of wastewater

treatment processes and impacts in different countries are also studied.

b) Field Observations

To understand and obtain clear picture of the study areas and the socio-economic situation of the

would-be affected households, observation have been made in the field. The eastern, western and

southern trunk lines, the treatment plant and the downstream areas in Akaki-Kaliti sub-city (District

7) have been visited. The community that would be affected are interviewed. The asset enumeration

was made based on the design documents and following strict surveying investigation techniques

together.

c) Public Consultation

The opinion of the PAPs households and their attitude towards the project was assessed through

consultations with the affected households. In the consultation process, the project-affected districts

were first briefed on the objective of the project and the spatial extent of the project area.

The districts stakeholders have also been consulted about the project objective and the anticipated

socio-economic impact. All meetings are supported with minutes. The minutes of the meetings are

incorporated in the RAP report.

d) Household Survey

Along the sewer lines all households have been surveyed and total enumeration was conducted and

the assets that would be affected are valued based on the guidelines set by the Addis Ababa

Municipality. The household survey was also conducted in areas around the treatment plant and

downstream areas. It should be noted that the settlement around the treatment plant is very low.

Therefore, the sample size is small.

7.4 The Main Stakeholders in the Project Area and the Consultation Process

The different stakeholders in the project area are the following.

District and Sub-city authorities and relevant experts of the Akaki-Kaliti, “Nefa Silik Lafto” and

“Kirkos” sub-cities.

Authorities and experts of the seven districts, sectoral offices of the above four sub-cities.

The PAPs at the grass root local community level in the seven districts along the wastewater sewerage

line and treatment plant extension and rehabilitation project areas.

7.4.1 Consultation with sub city administrations

The consultation process with the sub city administration and with authorities from selected districts

was done through interviews and discussions. The main points discussed were:

Existing environmental and socio-economic condition of the would be affected persons.


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Major socio-economic and environmental problems in the affected area

Major economic and social impacts (positive and negative) of the proposed project

Proposed mitigation measures in the course of project implementation

The opinions, perceptions and suggestions of the stakeholders.

7.4.2 Consultations with the Project Affected Persons

The main points raised during consultation meetings and interviews held with the PAPs after

informing them about the project objectives were the following.

current/existing social and economic problems of PAPs

Problems anticipated by PAPs during the project implementation and operation

Proposed mitigation measures for the anticipated problems and challenges

Opinions, perceptions and attitudes of PAPs about the project.

Major benefits of the proposed project and likely negative effects

Necessary preparations for the project implementation

Compensation implementation mechanism

The minutes of all discussions held with stakeholders are annexed in Volume II.

7.5 Type of Stakeholders

Two types of stakeholders can be identified i.e. internal and external. The list is given below. It

should be noted that these stakeholders are the main ones. Indirectly many others can be positively

affected by the proposed project. However, these are not included in this list.

7.5.1Internal stakeholders

The main internal stakeholders are the following.

“Addis Ababa City Administration (AAWSA)

The Addis Ababa City Administration, Environmental Protection Authority

Nefas Silk Lafto Sub city Administration

Nefas Silk Lafto District Eight Administration

Nefas Silk Lafto District Nine Administration

Nefas Silk Lafto District Ten Administration

Nefas Silk Lafto District Twelve Administration

Akaki Kaliti District Five Administration

Akaki Kaliti District Six Administration

The PAPs and organizations

Addis Ababa City Roads Authority

Ethiopian Electric Light and Power Corporation

Ethio-Telecom


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7.5.2 External Stakeholders

The external stakeholders include:

World Bank

The Federal Environmental Protection Authority currently reestablished as the Ministry of

Environment and Forestry

7.6 Roles of Main Stakeholders and Stakeholder Analysis

Stakeholder's analysis facilitates the assignment of duties and responsibilities to the different

organizations, facilitates coordination; creates wise use of human and material resources in the

settlement program. In brief, the tasks are outlined below.

7.6.1 Internal Stakeholders

The internal stakeholders have the following intervention activities to play for the successful

implementation of the proposed project.

A) Addis Ababa City Administration

Allocate budget to the client project office and monitor its utilization

Monitor the implementation and operation of the proposed project.

Coordinate the activities of the Sub-Cities and District Administrations for the

successful implementation of the project including the resettlement process.

B) Addis Ababa City Administration Environmental Protection Authority

Provide technical advice about environmental protection in the course of the project

implementation processes and beyond

Monitor the environmental safety in the project area pertinent to this specific project

Audit the project from environmental protection point of view

C) Ethiopian Electric Power Corporation

Follow-up the compensation of lost poles and replace on time to prevent power loss to the

project implementation areas households and factories.

D) Ethio-telecom

Follow-up the compensation of lost poles and replace on time to prevent communication

interruption to the project implementation areas, households and factories.

E) Addis Ababa Road Authority

Follow-up the compensation for the damage on asphalt, cobblestone and gravel roads.

Replace and facilitate road access immediately after the trunk line implementation at different

crossings.

Arrange and follow-up the provision of alternative access roads

F) Addis Ababa Water and Sewerage Authority

In addition to implementation of the proposed project, it shall coordinate the efforts of its branch

offices in the three Sub cities to follow-up and maintain water pipes that may be damaged during

project implementation.

Follow-up the rehabilitation of the affected part of forest area and “Behere Tsigie” Park


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7.6.2 External Stakeholders

A) The World Bank

Finance the project as per its agreement

Monitor and evaluate the progress of the work and check the correct use of the

allocated funds

Review work progress reports on the implementation of the project.

B) The Federal Environmental Protection Authority

As the project is big and important to the Addis Ababa City Administration in particular and

to the country in general the support and guidance by the federal Authority is needed

7.7 Stakeholder Analysis Summary

In general, the stakeholder analysis indicates that the project has enormous support both by the

community and the different stakeholders stated above. All District and sub-city authorities and

experts of the different sectorial offices support the project fully.

Table 7.1 below shows the opinion of project affected households along the sewer trunk lines. The

large majority (98.7%) of the households are in favor of the project.

Table 7.1: Opinion of the would be affected households about the project along the trunk lines

Opinion Number of

respondent’s

Percent

In favor of the project 294 98.7

Against the project 4 1.3

Total 298 100

Similarly, the household survey conducted around and downstream of the WTP indicates that 93.3 of

the respondents support the project. Out of 15 households surveyed only one household was against

the project. The reason for not supporting was that the treatment plant should be taken out of the

Addis Ababa city limits. It should be noted that most of the settlers around the WTP do not have

legal permissions from the municipality.

Table 7.2: Opinion of the would be affected households about the

project around and downstream of the WTP

Opinion Number of

respondents

Percentage

In favor of the project 14 93.3

Against the project 1 6.7

Total 15 100

In case of the project affected persons along the trunk lines the great majority of the respondents

support the project. However, they strongly demanded appropriate compensations and resettlement


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in a timely and just manner (details are included in the consultation minutes which are annexed in

Volume II.

All of them appreciated the project and stated the importance of proper wastewater disposal and

treatment in the city of Addis Ababa.

7.8 Concluding Remark

In general, the project has overwhelming support by the different stakeholders. All major

stakeholders along the sewer lines and the different sub-city and District officials and experts of

sectoral offices support the project. The great majority of the project-affected community supports

the project as long as proper compensation is made in a timely manner.


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8 ENVIRONMENTAL AND SOCIAL MANAGEMENT AND MONITORING

PLANS

8.1 Environmental and Social Management Plans

ESMP is the key to ensure that the environmental quality of the project area does not deteriorate due

to the implementation of the proposed development project. ESMP is generally used as the basis for

establishing the environmental behavior that the proposed project requires during its various stages

including the decommissioning phase.

The ESMP for the proposed project consists of set of mitigation and institutional measures to be

taken during the implementation and operation phases to eliminate the adverse environmental and

social impacts identified and predicted in the previous stages, offset them, or reduce them to

acceptable levels. The plan will also include the actions needed to implement these measures.

The ESMPidentifies feasible and cost-effective measures that will reduce potentially significant

adverse environmental impacts to acceptable level. The plan includes compensatory measures if

mitigation measures are not feasible, cost effective, or sufficient. Mitigation plan is a key to ensure

that the environmental qualities of the area will not deteriorate due to the implementation of the

project. The mitigation plan covers all aspects of implementation of the project in its different phases

related to environment.

Mitigation is the design and execution works, activities, or measures to reduce, or minimize the

negative impacts of the project on human and natural environments. It is the design and execution of

activities aimed at reducing significant impacts resulting from the implementation of the proposed

project. Mitigation can restore one or more environmental components to pre-impact quality. If this

is not possible, it can re-establish the original properties. The purpose of mitigation is therefore to set

in motion predesigned action to reduce the induced environmental impacts to acceptable levels.

Compensatory measures aim to produce a positive alternative effect to match identified adverse

effects, and are implemented only in areas where significant adverse impacts cannot be mitigated.

Environmental monitoring is an essential tool in relation to environmental management as it provides

the basis for rational management decisions regarding impact control. Monitoring should be

performed during all stages of the project (namely: mobilization, construction, post construction,

operation and decommissioning) to ensure that the impacts are no greater than predicted, and to

verify the impact predictions. The monitoring program will indicate where changes to procedures or

operations are required, in order to reduce impacts on the environment or local population. The

monitoring program for the present project will be undertaken to meet the following objectives:

• to monitor the environmental conditions of the project area;

• to check on whether mitigation and benefit enhancement measures have actually been

adopted, and are proving effective in practice;


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• to provide a means whereby any impacts which were subject to uncertainty at the time of

preparation of the ESIA, or which were unforeseen, can be identified, and to provide a basis

for formulating appropriate additional impact control measures

• to provide information on the actual nature and extent of key impacts and the effectiveness of

mitigation and benefit enhancement measures which, through a feedback mechanism, can

improve the planning and execution of future, similar projects.

Separate plans are prepared for the three parts of the project as in the previous chapters. These are

the sewer trunk line, the wastewater treatment plan and the area downstream of the plant. The

management plans are further subdivided into the different phases of the project: mobilization,

construction, post-construction, operation and decommissioning phases. As regards the area

downstream of the project, the plans are made in parallel to the phases at the WTP.


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Table 8.1 Environmental and Social Management Plan for the Sewer trunk Line Part of the Project

Issue/Environme

ntal Impact

Mitigation measures Mitigation schedule Responsibility

Implementation Supervision

Mobilization Phase

Land and Property

Acquisition

The temporary and permanent acquisition or obtaining of land for onsite works

shall be carried out in accordance to the RAP and entitled Framework for the

project. It shall be ensured that all RAP activities are reasonably completed

before the construction activity starts. All grievances of the RAPs will be

reasonably redressed, in accordance to the RAP implementation mechanism

suggested for the project.

Before construction starts AAWSA Grievance Handling

Committee

Flora awareness creation to the workers Beginning of phase AAWSA Consultant

building soft communication between the residents and workers Contractor Consultant

encouraging residents to collect their vegetables before the project activities Contractor Consultant

Only marked trees are to be felled within the sewage trunk main alignment whole phase Contractor AAEPA

Safety

(Accidents)

Provision and using of protective wear Whole phase Contractor site manager

Appropriate warning signs shall be placed in areas where accidents are expected

to occur

site manager

Strict prohibition of operation of equipment by unauthorized personnel site manager

Construction Phase

Air Dust suppression by water sprinkling Whole phase Contractor site manager

Soil Use of well maintained machinery without leaking fluids. Whole phase Contractor (should

be included in the

Site manger

Replacement of lubricating oil only in designated areas. Site manger


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Issue/Environme

ntal Impact



Limitation of movements of heavy machinery and vehicles to the access roads

and the designated construction site.

contract document) Site manger

Reduction of soil erosion by limiting excavation and other earthworks to dry

seasons

Site manger

Covering the trench as soon as possible Site manger

collecting the excess excavated soil and dumping in pre-planned sites Site manger

Implement erosion prevention mechanisms Site manger

Water Bodies covering the trench as soon as possible Whole phase Contractor Site manger

collecting the excess excavated soil and dumping in pre-planned sites Site manger

Implement erosion prevention mechanisms Site manger

Limiting the excavation and other earth works to the dry season (if possible) Site manger

Flora Demarcation and fencing off the construction areas Whole phase Contractor Site manger,

Consultant

Limiting the construction activities within the demarcated areas to an area that is

as small as possible.

Site manger

restricting clearing or removal of trees to the imperative area needed Site manager,

Consultant

preserve indigenous trees wherever technically feasible Site manager,

Consultant

implement replanting program End of construction

phase

AAWSA AAEPA

Fauna prohibit poaching and killing of wildlife by the workforce Whole phase Contractor Site manger

backfilling of trenches and other excavated areas and grading to the natural

topography

as soon as works are

completed

Contractor Site manger

awareness creation for the project personnel prior to the

commencement of the

construction works

AAWSA Consultant

Traffic liaison with local communities Whole phase Contractor Site manager


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Issue/Environme

ntal Impact



good site management (restrictions on construction hours, and limits on the

amount of construction that can occur at any one location at one time)

provision of access to all businesses and properties

Whole construction

phase

Contractor Site manager

utilizing trenchless technology in high traffic roadways when necessary Contractor Consultant

Health Provision and use of protective wear whole phase Contractor Site manager

Awareness creation on HIV/AIDS and other STDs Beginning of phase AAWSA Consultant

Safety Provision and use of protective wear Whole phase



to occur

isolating the work areas

Strict prohibition of operation of equipment by unauthorized personnel

following safety procedures

introducing a traffic plan with speed and traffic regulation Whole construction

phase


Post-Construction Phase

Soil (littering) awareness creation Beginning of phase Contractor Site manager

proper waste disposal Whole phase

immediate cleaning of the area End of phase

Water

Bodies

awareness creation Beginning of phase Contractor site manager

proper waste disposal Whole construction

phase


Flora awareness creation Beginning of phase AAWSA Consultant

proper waste disposal Whole construction

phase

Contractor site manager



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Issue/Environme

ntal Impact



Health backfilling pipeline trenches and other excavated places and grading to the

surrounding topography

immediately after

completion of site works

contractor site manager

draining pools (if any) immediately after

completion of site works

Safety Provision / use of protective wear Whole construction

phase

contractor site manager


to occur


Decommissioning Phase

Air

sewage odor, dust,

and vehicular

emission

the use of protective wear Whole phase Prospective

contractor

site manager

Soil

Spillage of sewage

waste

proper site management Whole phase Prospective

contractor

site manager

Health and safety

Minor accidents,

dust and other

emissions contamination by

sewage

Using protective wearing,

proper site management

Whole phase Prospective

contractor

site manager

Table 8.2 Environmental and Social Management Plan for the Wastewater Treatment Plant

Issue/Environmenta

l Component



Mobilization Phase


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Issue/Environmenta

l Component



Ambient air Unpaved access roads shall be regularly water sprayed

Whole phase Contractor Site manager Setting speed limits on unpaved access road

Preventive maintenance of vehicles and construction equipment

Soil Providing toilets to workers Whole phase Contractor Site manager

restricting maintenance in workshops

Flora Demarcation and fencing off the construction areas Whole phase Contractor Site manger, Consultant

Water sprinkling Site manager

Health giving orientation to workers about safety procedures Beginning of phase Contractor Consultant

Awareness Creation on HIV-AIDS and STDs Beginning of phase AAWSA Consultant

erecting traffic signs in the WTP site Whole phase Contractor Site manager

Providing protective wear to workers

availing first aid services

Safety Appropriate warning signs shall be placed in areas where accidents are

expected to occur

Whole phase Contractor Site manager

Providing protective wear to workers


availing first aid services

Construction Phase

Ambient air Dust suppression activities (water roads and exposed ground) Whole phase Contractor Site manager

Minimize disturbed areas Site manager Consultant

Backfill exposed construction site as soon as possible Site manger

Limit stockpile height of topsoil to 2m maximum

Construction materials shall be covered during transportation by truck

Setting speed limits on unpaved access road


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Issue/Environmenta

l Component



Preventive maintenance of vehicles and construction equipment

Water

Bodies

locating storage areas and compounds away from watercourses Whole phase Contractor Site manager consultant

appropriate storage of fuel and materials Site manager

providing suitable facilities for workers, Site manager

disposing of waste according to a waste management plan Site manager

Soil providing suitable toilet facilities for workers Whole phase Contractor Site manager

proper handling fuels and oils Site manager consultant

construction sequencing Site manager

locating stockpiles away from watercourses Site manager consultant

Reduction of soil erosion by limiting excavation and other earth

work to dry seasons (if possible)

Site manger

consultant

protecting exposed areas prone to erosion during heavy rain, if

necessary putting silt traps in watercourses

Site manager consultant

re-vegetating exposed areas End of phase AAWSA Consultant

disposing grit, screenings and sludge from existing lagoons in landfill Whole phase Contractor Consultant

Flora Water sprinkling for dust suppression Whole phase contractor site manager

Speed limiting Site manager

Limiting the construction activities within the demarcated areas to an area

that is as small as possible.

Site manager Consultant

Collection of solid waste only at earmarked areas and appropriate

disposal

Site manager

restricting removal of trees and vegetation to the imperative area needed

for the project activities

preserving, wherever technically feasible, indigenous trees

Whole phase Contractor Site manager Consultant

implement a replanting program End of phase AAWSA Consultant


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Issue/Environmenta

l Component



Health awareness raising and education programs about HIV/AIDS and other

STDs

Beginning of phase AA Health Bureau AAWSA

Noise

Noise

Avoiding unnecessary transportation of materials to reduce traffic.

Limitation of transport activities to day-time as much as possible to

reduce noise.

using low-noise equipment and machinery if possible

Silencers or mufflers shall be used on construction equipment.

programmed maintenance of vehicles and equipment

Whole phase Contractor Consultant

incorporating low-noise equipment in the design design phase Contractor Consultant

locating noisy mechanical equipment in properly acoustically lined

buildings

design and construction

phase

contractor consultant

Providing greenbelt along the periphery of the WTP End of phase AAWSA WTP manager

Safety Provision of protective wearing

Appropriate warning signs shall be placed in areas where accidents are

expected to occur

Whole construction

phase



locating borrow pits far from settlements

Post Construction Phase

Ambient air Unpaved access roads shall be regularly water sprayed Whole phase Contractor, Site manager

Setting speed limits on unpaved access road

Preventive maintenance of vehicles and construction equipment to reduce

vehicle emissions

Soil Careful dismantling of equipment to avoid any spillage Whole phase Contractor Sit manager

water spraying

introducing speed limit to suppress dust

cleaning the area


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Issue/Environmenta

l Component



Water

Bodies

Immediate cleaning,

controlled dismantling

properly disposing waste

Whole phase Contractor AAEPA

Health awareness raising and education programs about HIV/AIDS and other

STDs

Beginning of phase AAWSA Consultant

backfilling excavated places and grading to the surrounding topography

draining pools

immediately following

completion of works

contractor Site manager

Safety Providing protective wear to workers Whole phase contractor Site manager

erecting traffic signs Site manager

giving orientation to workers about safety procedures Beginning of phase Site manager

availing first aid services Whole phase Site manager

Operation Phase

Ambient air proper housekeeping procedures (regular cleaning of the grit and

screenings)

facility maintenance

Whole phase AAWSA WTP manager

proper operational practices including process control and chemical

treatment

continuous process of the operation

Running the UASB at optimum condition

WTP manager

Planting shrubs and trees along the periphery Beginning of phase AAWSA WTP manager

Soil dispose sludge with dangerous substances in sanitary landfill Whole phase AAWSA WTP manager

Water

Bodies

dispose the sludge with dangerous substances in landfill Whole phase AAWSA WTP manager

All pipe work and fittings should be a class A rating in excess of the

maximum pressure attained in service including any surge pressure.

Construction phase Contractor consultant

Fauna proper quality control of “treated” wastewater and sludge before

releasing

Whole phase AAWSA WTP Quality Control

Health provision of buffer zones between the plant and the rest Construction phase contractor consultant


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Issue/Environmenta

l Component



proper planning of the project operation and maintenance Operation phase AAWSA WTP manager

Safety Adherence to national rules and regulations Whole operation phase AAWSA WTP manager

Appropriate warning signs shall be placed in areas where accidents

are expected to occur

WTP manager

Provision and use of protective wears

Strict prohibition of operation of equipment by unauthorized

personnel

WTP manager

Operators shall be provided with regular medical check-up and

safety training

WTP manager

Decommissioning

Ambient Air

Quality

sewage odor,

vehicular emission

using protective wear

Soil Spillage of sewage

waste or

contaminated water,

sludge, chemicals,

oil, etc.

proper site management

Health and safety Minor accidents, dust

and other emissions f contamination by

sewage

Use protective wearing

followgood site management plan


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Table 8.3 Environmental and Social Management Plan for the Area Downstream of the WTP

Issue/Environmental

Component

Mitigation measures Mitigation

schedule

Responsibility


Operation Phase

Water

Bodies

only use part of the treated wastewater for irrigation always District admin.

AAWSA

AAEPA

Fauna proper quality control of “treated” wastewater and sludge before

releasing

Whole operation

phase

AAWSA WTP Quality Control


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8.2 Environmental and Social Monitoring Plan

The environmental monitoring program is developed to provide a basis for evaluating the efficiency

of the proposed mitigation measures and for updating of the actions and impacts of baseline data. It

also gives information for adoption of additional mitigation measures if the proposed measures are

found insufficient. Thus, it avails information for management decisions taking in the different

phases of the project.

Monitoring methodology involves:

identification of the relevant monitoring standards;

identification of components to be monitored;

identification of parameters to be used for monitoring

setting the monitoring frequency and responsibilities for monitoring

visual observations and testing of environmental parameters

The table below shows the proposed monitoring plan.


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Table8.4 Environmental and Social Monitoring Plan

Category Type of Monitoring Frequency Monitoring Party

Mobilization/Pre-Construction Phase

Air pollution Dust and vehicular

emission

Monitor adequacy of dust suppression measures undertaken

Monitor that vehicles and construction equipment are regularly

maintained

Daily AAEPA/Consultant

Storage and transportation

of construction materials,

excavated soil and silt

Monitor adequacy of measures undertaken to prevent fugitive

dust


Trees • Limiting affected zone

• Trees cutting

Ensure that the construction areas are demarcated (fenced)

Ensure that only marked trees are cut

Weekly AAEPA

Awareness creation Non professional workers Environmental protection (flora, fauna, waste disposal, etc) HIV-

AIDS and STDs safety procedures

Beginning of phase Steering Committee

Semi professional workers

and sub contractors

Environmental protection, maintenance requirements, site

management

Beginning of phase Steering Committee

Project affected people

HIV-AIDS, STDs, safety procedures, project schedule

Beginning of phase

Steering Committee

Environmental

Monitoring • Ambient air quality

• Water quality

• Noise level

Monitoring ambient air quality, water quality, and noise levels at

plantation forest, WTP and downstream area:

• Ambient Air Quality Parameters- NOx, SPM, SO2, and

CO

• Water Quality (pH, Conductivity, Hardness, Turbidity,

Temperature)

•Noise Levels- Hourly, Day and Night Time Values

Once during

construction (dry

season)

AAEPA


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Construction Phase

Air/ Pollution Dust and vehicular

emission



maintained






dust


Soils Excavation and back filling Monitor adherence to contract specifications Daily AAEPA/Consultant

Erosion Monitor proper management of excavated soil/silt including

timely removal of material from construction site

Monitor that stockpile height of topsoil does not exceed 2m

maximum

Monitor that slope protections and grading to the natural

topography are done

Monthly AAEPA/Consultant

Contamination Monitor that equipment, machinery do not have leakages

Monitor that there are no oil and chemical spills

Daily Consultant

Surface and Ground

Water Quality

Surface runoff management

at construction site(s)

Monitor measures to channelize surface runoff

Monitor that storage areas and compounds are located away

from watercourses

Monitor that fuel and materials are stored appropriately (are

not prone to damage)

Daily AAEPA/ AALSAB/

Consultant

Contamination from waste

and sewage generated from

construction activities

Monitor measures taken to prevent contamination of ground

and/or surface water from waste and sewage generated from the

project activities


Flooding/Water

logging

Blockage of drainage due to

construction activities

Monitor to ensure construction activities do not cause flooding or

water logging at the project sites.

weekly AAEPA/Consultant

Solid Waste Disposal of construction

and other wastes

Monitor to ensure construction and other wastes are being

disposed in approved sites

daily AAEPA/Consultant


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Fauna Protect wildlife Monitor that the workforce is not poaching and killing wildlife in

plantation area

Daily AAEPA/ Consultant

Noise Noise from construction

vehicles

Monitor that noise emissions are within acceptable limits 2-3 months AAEPA

Health and safety of

construction

workforce

Health and safety

requirements

Monitor adherence to all occupational health and safety

requirements

Weekly AALSAB/ Consultant

Provision of health and

safety protection kit

Monitor availability of adequate number of protective kit

Monitor that workers are using protective kit

Monthly AALSAB/ Consultant

Health check up of workers Monitor availability and adequacy of health service to workers Monthly AALSAB/ Consultant

Sanitary conditions of

construction campsites

Monitor provision of shelter, water supply, excreta and solid

waste management at campsites

Monitor that separate toilet services for women and men are

provided

Monthly AAEPA/ AALSAB/

Consultant

Road Safety and

Traffic Management

Traffic management plan Obtain approval to traffic management plan from Addis Ababa

Traffic Police

Before

construction

AAEPA/ AALSAB/

Consultant

Monitor adherence to the traffic management plan Weekly AAEPA/ AALSAB/

Consultant

Review road safety record

Review and monitor road safety records to ensure all project

related road accidents are being properly investigated and

reported

Monthly Contractor AAEPA/

AALSAB/ Consultant

Socio- Economic

Activities

Access to public and

private properties

Monitor impact of project on dwelling and business in the

project area

Daily AAEPA/ AALSAB/

Consultant

Damage to public and

private property

Monitor that public and private properties are not damaged by

construction activities (other than those included in the

compensation plan)

Weekly Contractor/ AAEPA/

AALSAB/ Consultant

Review and monitor property damage report to ensure timely

resolution of claims etc.

Monthly Contractor/ AAEPA/

AALSAB/ Consultant


150



Hardship and

inconvenience to public and

business

Monitor to ensure that communities and business face minimal

hardship and inconvenience due to project activities

Weekly Contractor/ AAEPA/

AALSAB/ Consultant

Public Awareness Aware the public about:

• the long term benefit

of the project

• the need for public

cooperation

• Health and safety risks

Review and monitor effectiveness of the awareness campaigns

conducted

Fortnightly Steering Committee

Environmental

Monitoring during

construction

• Ambient air quality

• Water quality

• Noise level


Eastern and Western Trunk, WTP and downstream area:


CO


Temperature)


Once during

construction (dry

season)

AAEPA

Post Construction Phase

Air pollution Dust and vehicular

emission



maintained






dust


Solid Waste Disposal of construction

wastes and other wastes

Monitor to ensure construction and other wastes are being

disposed in approved sites

Monitor sites are properly cleaned

daily AAEPA/Consultant


151



Safety Provision of health and



Monitor that workers are using protective kit

Monthly site manager

Noise Noise from construction

vehicles

Monitor that noise emissions are within acceptable limits 2-3months AAEPA

Post Construction

Environmental

Monitoring


• Water quality

• Noise level


Eastern and Western Trunk, WTP and downstream area:


CO


Temperature)


Once after

construction (dry

season)

AAEPA

OPERATION PHASE

Operation and

Maintenance of the

System

Operation Monitor :

• correct and design operation of every system unit

• emergency procedures and requirements (availability)

• timely completion of work,

Monthly AAWSA/AAEPA/AALA

B

Maintenance

• adequacy of implementation of preventive and all

unscheduled/emergency maintenance work

• periodic housekeeping of the system,

• allocation of human and financial resources for the

preventive and unscheduled maintenance

Monthly AAWSA/AAEPA/AALA

B

Soil Contamination Monitor that sludge with dangerous substances is disposed in

sanitary landfill

Monthly AAEPA

Health and safety of

workforce

Health and safety

requirements

Monitor adherence to all occupational health and safety

requirements

Weekly AALAB


152



Provision of health and



equipment needed

Monthly AALAB

Maintenance of health and

safety records of work force

Review and monitor health and safety records to ensure all

project related accidents are being properly investigated and

reported

Monthly AALAB

Surface and Ground

Water Quality

Contamination from waste

and sewage

Monitor Weekly Performance of WTP Weekly at site

laboratory and

every 3 months at

EPA laboratory

AAWSA/AAEPA

Environmental

Monitoring during

Operation


• Water quality

• Noise level


WTP:


CO


Temperature)


Once during

construction (dry

season)

AAEPA


153


8.3 Implementation Arrangement of the EMMP

A Project Steering Committee (PSC) that is composed of officials from the city administration,

AAWSA, affected sub cities, AAEPA, AASLAB, MoWUD, AARA, EEPCo, should be established.

The PSC will oversee the whole work and coordinate collaboration between different concerned

offices and bodies. It will meet once a month to review progress, to discuss the implementation

issues and give directions. The implementation of all the physical works will fall under the

responsibility of AAWSA. However, if need be it can be strengthened with additional engineers and

environmentalists. AAWSA shall also have an Environment and Safety Section that will follow up

the EMP during project implementation and operation to avoid or minimize potential negative

impacts. AAWSA should hire consultant/s and contractor/s for the construction and installation

activities. The respective contractor/s shall have environmental specialist to provide key inputs to the

project implementation. The environmental monitoring / auditing will be carried out by AAEPA and

(AASLAB) through a checklist. This checklist will be developed by the Consultant as part of the

construction supervision plan. An awareness creation committee shall be formed that will be

responsible for the awareness creation to the public, the semi professional workers and the other

workers. It will be composed of experts from AAEPA, AAWSA, AASLAB, AAHB and the

consultant. The proposed implementation arrangement for the project is shown in Figure 8.1:

Figure 8.1 Proposed organization chart for the implementation of the EMMP

Project Steering

Committee

AAEPA

Contractor

Environment and

Safety Division

Contractor’s Environmental

Management Unit

AAWSA Awareness Creation

Committee


154


8.4 Training on Environmental Aspects

Training on environmental and safety aspects will be organized by the ACC for all officials

associated with the project and contractors’ work force. The training will be conducted in different

phases: for technical officials and for workers of contractors. The training course will focus on

environmental and safety issues during the different phases of the project, orientation of

environmental legislation in the country, case histories of similar projects completed, elaboration on

the EMMP for easy comprehension. In addition, there will be awareness creation to the public.

Detailed training modules may be prepared by the ACC, before project implementation as part of

supervision plan.

8.5 Environmental Management Budget

The environmental management budget in the project comprises environmental monitoring,

compensatory plantation, and training and awareness creation and compensation for the PAP. The

table below gives a summary of the budget.

Table 8.5 Summary of the budget for environmental management

Component Stage Item Quantity Total Cost in Eth

Birr

(A) Mitigation/Enhancement Measures

Air All phases Dust Management

with sprinkling of

water,

Covering

construction material

during transportation

by vehicles

Part of Contract

Water quality Construction erosion prevention

mechanisms

Silt fencing around

stockpiled soil near

water

Part of Contract

Construction Incorporate water

impermeable layers

in the sludge drying

beds

Should be covered

in engineering cost

(not considered in

the present design

but it should be

included)

Soil contamination Construction Construct landfill Should be included in

Engineering Costs

All Phases proper waste

disposal

Part of contract cost

Operation disposing grit,

screenings and sludge

from existing lagoons

in landfill

Operation cost


155



Birr

Flora Construction Demarcating

construction areas

Part of Contract

Post Construction Compensatory

plantation program at

least 3 saplings for

each tree felled

(staggered to follow

Civil Works)

including 3 years

maintenance

400,0004

Fauna

Construction Proper fencing of the

WTP compound

Birr 200/m2 Should be included in

the engineering cost

(but not included in

the present design i)

Health

Post construction draining pools (if

any)

Part of Contract

All phases Availing Health

Services

Part of Contract and

Operation cost

Safety All phases Demarcating Borrow

Areas

Placing appropriate

warning signs

Provision and use of

protective gears

Part of Contract and

Operation cost

Traffic At crossings with the

Ring Road and the

New Railway Line

utilizing trenchless

technology in high

traffic roadways

Should be included in

the engineering cost

(but not included in

the present design)

Total 400,000

(B) Monitoring and Training Costs

Air Preconstruction Monitoring one

location each at the

eastern and western

sewer trunk line one

at the WTP site and

one in the

downstream area

4 qualities 4 locations

at Birr1000 each

16,000

Construction Same as in pre

construction phase


at Birr1000 each

16,000

Post construction

Same as in pre

construction phase


at Birr1000 each

16,000

Operation At WTP 4 qualities 1 location

at Birr1000 each

4,000

Water quality Preconstruction Monitoring one 5 qualities 4 locations 2,000

4 5workers for 10 months/year for 3 years at Birr2,000 per month plus cost of saplings


156



Birr


eastern and western


at the WTP site and

one in the

downstream area

at Birr100 each


construction phase


at Birr100 each

2,000

Post construction Same as in pre

construction phase


at Birr100 each

2,000

Operation At WTP Built into operation

costs of WTP

At Little Akaki River Built into operation

costs of WTP

Soil Operation Monitoring that

sludge with

dangerous substances

is disposed in sanitary

landfill

Part of operation cost

Flora (Pre) Construction Monitoring that only

marked trees are cut

Birr 200/person/day

Fauna construction Monitoring that

poaching and killing

of wildlife by the

workforce is not

practiced

Birr 200/person/day

Noise Preconstruction Monitoring one


eastern and western


at the WTP site and

one in the

downstream area

4 locations at Birr

5,000 per location

20,000


construction phase

4 locations at Birr

5,000 per location

20,000

Post construction Same as in pre

construction phase

4 locations at Birr

5,000 per location

20,000

Operation At WTP One location 5,000

soil Operation WTP Sludge

Characteristics

Part of operation cost

Training Preconstruction 1 Program for official

rank

1 program for

Workers of

contractors

1 program for

technical staff of

250,000


157



Birr

WTP

1 program for other

Workers WTP

1program for public

Monitoring and training cost 373,000

Total Cost (A)+(B) 773,000

Contingency 10% 77,300

Grand Total 850,300


158


9 SUMMARY OF THE COST ESTIMATES FOR THE PROPOSED

MITIGATION MEASURES

The cost for RAP can be categorized as implementation cost and administrative costs. The details of

how the budget was calculated is given in the RAP report (Volume II)

a) RAP Implementation budget

The budget that will be required to implement the RAP is worked out based on the inventory made

by the consultant in the project area, i.e., along the trunk lines. On this basis, the required cost for

compensation is calculated using the rates indicated in the RAP report.

The budget includes compensation for loss of crops and trees, for rehabilitation/resettlement

measures (income restoration, skill training, transportation costs, etc). Table 9.1 summarizes the

budget associated with the compensation for the PAPs.

Table 9.1: Estimated cost for compensation

Description Unit Quantity Unit rate5 Total comp. Amount

Housing unit with block wall& CIS roof m2

1510 3500.00 5,285,000.00

Housing unit with mud wall & CIS roof m2

5200 600.00 3,120,000.00

Housing unit with stone wall & CIS roof m2 40 3000.00 120,000.00

Housing unit with CIS wall and roof m2 3914 300.00 1,174,200.00

Foundation for housing unit m2 181 1500.00 271,500.00

Septic tank m3 348 2000.00 696,000.00

Fuel tank m3 208 5500.00 1,144,000.00

Fence with stone m2 610 400.00 244,000.00

Fence with CIS m2 2000 200.00 400,000.00

Fence with block m2 1428 450.00 642,600.00

Stone retaining wall m2 90 400.00 36,000.00

Eucalypts tree piece 397 350.00 138,950.00

Telephone poles piece 26 1000.00 26,000.00

Electric pole s piece 89 2500.00 222,500.00

Asphalt road m2 1719 874.00 1,502,406.00

Coble stone road m2 616 397.48 244,847.68

Gravel road m2 2349 300.00 704,700.00

Total 15,972,703.68

Social and Psychological cost @5 % 798635.18

Contingency @ 10% 1597270.37

Sub- total 18,368,609.23

5 Estimated based on the compensation guideline of Addis Ababa city administration


159


With regard to the cost required for the committee that shall be formed to implement the proposed

compensation plan effectively, it is estimated by taking into considerationthe necessary days, the per-

diem and fuel requirements. Table 9.2 gives this summary.

Table 9.2: Estimated administration cost of RAP implementation for 7 Districts

S/N Members Position Day Unit rate /Birr No. of District Total

1 District Administration Chair Person 7 150.00 7 7,350.00

2 Member 7 150.00 7 7,350.00

3 District Finance & economic office Member 7 150.00 7 7,350.00

4 District Land administration Member 7 150.00 7 7,350.00

5 Community representative Member 7 150.00 7 7,350.00

6 AAWSA Member 7 150.00 7 7350.00

Sub Total 1 44,100.00

1 Driver 7 100.00 7 4,900.00

2 Surveyor 4 130.00 7 3,640.00

3 Daily laborer 4 80.00 7 2,240.00

4 Fuel (150 km will be covered) 19.00 7 19,950.00

5 Oil ( 5 kilo per car) 80.00 7 2,800.00

Sub Total 2 33,530.00

Total=Sub Total 1+ Sub Total 2 7 77,630.00

Contingency @ 10% 7 7,763.00

Grand total 85,393.00

Thus, the total cost for compensation is estimated to be Birr 18,454,002.23, out of which the direct

compensation cost accounts for 99.56%.

b) Environmental management and monitoring budget

The environmental management budget includes the following (see Table 8.5 for detail):

cost for mitigation and enhancement including 10% contingency 440,00

cost for monitoring and training including 10% contingency 410,300

The total environmental management and monitoring budget will be 850300

Thus, the overall cost, i.e. including compensation, mitigation and monitoring as detailed in Tables

9.1, 9.2 and 8.5 becomes about ETB 19,400,000.


160


10 CONCLUSIONS AND RECOMMENDATIONS

10.1 Conclusions

The Kaliti WTP which is found in the Kaliti catchment started operating in 1983. It has a design

capacity of about 7,500 cubic meters per day or an equivalent population of 50,000.The present

coverage of the wastewater management of the city is not greater than 9.8%. The existing sewer lines

cannot accommodate the high volume of sewage waste as a result of which sewage overflows on to

streets and into the watercourses. Septic pump-out trucks do not access all areas to service the new

high volume customers. Sewage from septic tanks and latrines continue to pollute groundwater.

There are uncontrolled and open wastewater disposal, illegal connections of sewerage to storm

drainage lines and to nearby rivers. The situation is affecting the public health and the aesthetics of

the city. The existing lagoon treatment system is already operating beyond its design capacity.

Considering all this condition of the city, the need for an improved wastewater management system

(wastewater treatment plant and collection system) is indisputable.

It is therefore, planned to expand the existing sewer line and install a new wastewater treatment

plant. The new treatment plant will be installed in the same site where the existing plant is operating.

The existing plant will continue to work until the new plant becomes operational. In order to

maintain current treatment as well as future goals, UASB and high rate Trickling Filtration systems

are recommended for the new treatment plant. In the first phase, the new plant will have a capacity to

treat 100,000m3/d, which is more than 13 times greater than the existing capacity. The new sewer

trunks that will be built will relieve the existing sewer lines.

The selected technology for the new treatment plant allows the possibility of installing other

necessary treatment systems on the existing site without needing additional land and without

disrupting the existing treatment systems. It also allows the existing lagoon systems to be used for

tertiary treatment and storage.

The selection of the treatment technology was carried out based on construction and operation cost,

space requirement, ease of operation, etc. Accordingly, the selected treatment technology is

appropriate.

Modifications to the existing sewer trunk line are proposed in order to achieve the future goal of

increasing sanitary service within the Kaliti catchment. Increasing the capacity of the sewerage

system will prevent flows from being diverted directly into rivers, which will prevent eutrophication

of water bodies and possible detrimental health effects.

The selection of the sewer trunk routes was governed by many constraints:

The preference for gravity flow system

The proposed large diameter sewer trunks

The unstructured nature of the roads and buildings

The presence of local creeks,


161


the management of compensation process for private properties to obtain a right-of-

way for the construction of the sewer trunk lines

The preference for use of gravity system is commendable since it will avoid problems associated

with power interruptions and will minimize the operating cost of the sewer lines. Therefore, the

selected routes for the sewer trunk lines are appropriate. The analysis of various alternatives carried

out indicates that selected options are environmentally sound.

The environmental and social impacts of the project have been studied dividing the project into three

parts: the area where the sewer trunk lines are to be built, the WTP and the area downstream of the

WTP.

A total number of397trees are likely to be cut in the Sewer trunk line area. Most of the

environmental impacts identified in the sewer trunk line area, are of minor to medium significance

and of short-term duration. Therefore, they can be mitigated following the proposed mitigation

measures. As regards the socio-economic impacts in this part of the project, both positive and

negative impacts have been identified. The negative impacts include land, property and social issues.

Moreover, the PAPs have shown positive attitude for the project so far as they get proper

compensation. Accordingly, a compensation and resettlement action plan with a grievance

accommodation mechanism has been developed to respond for the PAPs.

Many of the adverse environmental and socio-economic impacts in the WTP site are minor and can

be easily mitigated. The identified “major impacts” are all subjective which may happen under rare

conditions, as in case of negligence, accident, etc. These also have appropriate mitigation measures

and are indicated in the ESMP.

Downstream of the WTP, the impacts are mainly positive since the effluent that will be discharged

into Little Akaki River will be as per specified standard. The effluent from WTP will therefore be of

a higher quality than the water in this river and will provide improved condition for the river

ecosystem.

The noise levels in project area are anticipated to be within the stipulated limits. There is no

existence of endangered species of flora and fauna in the project area. The proposed project will give

a long-term solution to the sewage disposal needs of Addis Ababa. With proper maintenance and

environmental monitoring, the project is not expected to have adverse effects on the environment and

on the surrounding community.

In general, the ESIA study indicates that the implementation of the project is expected to have

enormous significance. The positive impacts by far outweigh the negative impacts. The

implementation of the project will improve the health and livelihood of the city residents and

downstream users of polluted river waters as it reduces the prevalence of waterborne diseases. The

project will also create short and long-term employment opportunities and potentially enables reuse

of the treated wastewater for agriculture and industrial purposes and allows to produce biogas for

energy and organic fertilizer (compost) from the by-products of wastewater treatment process in the

future. The sludge can also be used for electricity generation through pyrolysis.


162


The project is important and timely to reduce the problems associated with the disposal of

wastewater in the city of Addis Ababa. The project will certainly play important role in bringing

about a more ecologically, socio-culturally and economically sustainable and equitable environment

in the Kaliti sewer catchment of Addis Ababa city.

After a careful review of the design document and the existing and generated environmental baseline

data, the consultant has come to the conclusion that it is possible to mitigate almost all of the

environmental and socio economic impacts due to the implementation of the proposed project with

about ETB19,400,000(compensation/RAP and environmental and social management and

monitoring plan). Therefore, looking at the benefits against the negative impacts and the cost, this

project will be environmentally and socioeconomically feasible.

10.2Recommendations

Overall, the ESIA shows that the benefits of the Kaliti WTP and sewer line expansion and

rehabilitation project outweigh much more significantly than the adverse effects. The adverse

impacts identified can be mitigated through implementing the proposed management and monitoring

plans to acceptable limits. Therefore, it is recommended to implement the project with strict

observation to the environmental and social management and monitoring plans.

However, the project supervision consultant once mobilized should prepare “Construction

Supervision Plan” before the beginning of construction works and this plan should be part of the

contract. In addition, the environmental management plans should be made part of contract

documents of contractor so that ESMP compliance is ensured.

The ESMP recommends environmental monitoring at the different phases of the project. The

monitoring should be conducted to check the efficacy of mitigation measures. An environmental

checklist should be developed by the Environment and Safety Division for the daily environmental

audit of the project activities. This should be filled up by the environmental expert (EMU) of the

contractor and should be verified by the AAEPA.


163


SELECTED REFERENCES

AAWSA, 2001.Wastewater Master Plan – Volume 3, European Commission, p109.

AAWSA, 2002. Wastewater Master plan Volume III, Addis Ababa Water and Sewerage Authority, Addis Ababa, Ethiopia

AAWSA, 2010a. Detail Design of Wastewater Treatment Plants &Sewerage Network for Akaki Sewerage Catchments of

the City of Addis Ababa (Environmental and Social Impact Assessment Report). Addis Ababa Water and Sewerage

Authority. Addis Ababa, Ethiopia

AAWSA, 2010b.Feasibility study of treated waste water from the Kaliti treatment plant.Addis Ababa Water and Sewerage

Authority. Addis Ababa, Ethiopia.

AAWSA, 2012.Final irrigation feasibility report of Kaliti wastewater treatment plant expansion and rehabilitation and

sewer lines in the Kaliti sewage catchment. Addis Ababa, Ethiopia

Adrianus van Haandel and Jeroen van der Lubbe, 2007, Handbook Biological Waste Water Treatment – Design and

Optimisation of Activated Sludge Systems, The Netherlands, p570

Alberta Environment, 2000, Guidelines for Municipal Wastewater Irrigation, Edmonton, Alberta, p30.

DerejeNegussa, 2001. Groundwater pollution vulnerability Assessment using RDASTIC approach in Akaki river

basin.Unpublished M.Sc thesis.Addis Ababa University.

Environmental Protection Authority and the United Nations Industrial Development Organization, Guideline Ambient

Environment Standards for Ethiopia, 2003, Addis Ababa, p.103.

Environmental Protection Authority, Standards for Industrial Pollution Control in Ethiopia, 1997, Addis Ababa, p.35

Getnet Sewnet, 2012. Predictive modelling of kaliti wastewater treatement plant performance using artificial neural

networks.M.Sc Thesis.Addis Ababa University. P.97.

Government of Canada, 2010, Municipal Wastewater System Effluent Regulations, Vol. 144, No. 12, p69.

I. H. Farooqi, FarrukhBasheer and RahatJahanChaudhari, 2008, Constructed Wetland System (CWS) for Wastewater

Treatment, Faculty of Engineering and Technology, Aligarh Muslim University, Mississauga, pp1004-1009.

J. B. Ellis, R.B.E.Shutes and M.D.Revitt, 2003, Constructed Wetlands and Links with Sustainable Drainage Systems,

Environment Agency, Rio House, Bristol, p.190.

Merz, Sinclair Knight, 2000, Guidelines for using free water surface constructed wetland to treat municipal sewage,

Queensland Department of Natural Resources, Brisbane, p.133.

Metcalf & Eddy, Inc., 2003, Wastewater Engineering: Treatment and Reuse, 4th Ed., McGraw-Hill, New York, p.1819.

MogensHenze, Mark van Loosdrecht, George Ekama, DamirBrdjanovic (Editors), 2008, Biological Wastewater

Treatment – Principles, Modelling and Design, Cambridge University Press, p.518.

Roberto Reinoso, Linda Alexandra Torres, EloyBecares, (2008), Efficiency of natural systems for removal of bacteria

and pathogenic parasites from wastewater, Environmental Research Institute, University of Leon, Spain, p.7.

Urban Water Supply and Sanitation Project Environmental and Social Management Frame Work, June 2004


164


Wastewater Committee of the Great Lakes - Upper Mississippi River Board of State and Provincial Public Health and

Environmental Managers, 2004, Recommended Standards for Wastewater Facilities, New York, p.129.

World Health Organization (WHO), 2006, Guidelines for the safe use of wastewater, excreta and grey water, Volume 2:

Wastewater in Agriculture.


165


ANNEXES

Annex 1 List of Project Affected People and Property

Table A1.1 Goods and assets affected

Household number

Name of

household or

business owner Fathers name plot area

Description of houses and

construction

Use of the

property

level of effect

(total, partial,

minimum)

Tenure

status

Employment status

of all adults Comments

1 Yohans Dgafee 6.5 fence CIS Dwelling Partial Owner Business man

2 Samia Melena 39.4 fence CIS Dwelling Partial Owner civil servant

3 Kabansh Ferede 51.6 fence CIS Dwelling Partial Owner c servant

4 Woubshet W/gabriel 21.5 fence CIS Dwelling Partial Owner Business man

5 Tilahun Dgafee 30 mud house Dwelling Partial Owner Private

6 Sefa Oumer 60 mud house Dwelling Partial Owner Private

7 Aynalem Haddis 15.8 fence CIS Dwelling Partial Owner Business man

8 Mulugeta Mersha 14.5 fence CIS Dwelling Partial Owner Private

9 Bayush Dgafee 18 mud house Dwelling Partial Owner

10 Bezu Fikre 20.9 mud house &fence Dwelling Partial Owner small trade

11 Hailu shibeshi 13 fence CIS Dwelling Partial Owner Business man

12 Danil Alemayhu 116 mud house &fence Dwelling Partial Owner no job

13 Taytu Beyene 49 mud house Dwelling Partial Owner housewife

14 Weynshet

88 mud house &fence Dwelling Partial Owner housewife


166


Household number

Name of

household or



construction

Use of the

property

level of effect

(total, partial,

minimum)

Tenure

status

Employment status


15 Nimani Finet 140 mud house Dwelling Partial Owner farmer

16 Fantu Nemani 57.2 mud house Dwelling Partial Owner House wife

17 hasen Nesru 14 mud house Dwelling Partial Owner vender

18 Danil Talore 16 mud house Dwelling Partial Owner guard private emp.

19 Tedla Sige 20 mud house Dwelling Partial Owner guard private emp.

20 Ejigu Minda 30 mud house Dwelling Partial Owner guard private emp.

21 Alemnesh Ghana 77 mud house Dwelling Partial Owner House wife

22 Moke Kebede 0 mud house Dwelling Partial Owner daily laborer

23 Gonfa Hude 35 mud house Dwelling Partial Owner pension

24 Mewled Abdella 21 mud house Dwelling Partial Owner private

25 Lubaba Adem 52 mud house Dwelling Partial Owner house wife

26 Haru

7 fence CIS Dwelling Partial Owner Business man

27 Mudin Kemal 72 mud house Dwelling Partial Owner Business man

28 Fikre Moges 31 House & fence Dwelling Partial Owner Private

29 Mubarek Muzemil 32 mud house &fence Dwelling Partial Owner Business man

30 Degitu Daba 33 mud house Dwelling Partial Owner house wife

31 Dino Kedir 83 mud house Dwelling Partial Owner vender

32 Lemessa Koricho 55 mud house Dwelling Partial Owner Private emp.

33 Shikur Zeleke 28 mud house Dwelling Partial Owner civil servant

34 Tofik Ali 27 mud house Dwelling Partial Owner vender

35 Mustefa Mudesir 19 mud house Dwelling Partial Owner daily laborer

36 Miftah Shamil 25 mud house Dwelling Partial Owner daily laborer

37 Shiferaw kebede 46 mud house Dwelling Partial Owner private emp


167


Household number

Name of

household or



construction

Use of the

property

level of effect

(total, partial,

minimum)

Tenure

status

Employment status


38 Dejene Gashaw 18 mud house Dwelling Partial Owner daily laborer

39 Asrara Nesro 10 mud house Dwelling Partial Owner daily laborer

40 Fekie Hasen 38 mud house &fence Dwelling Partial Owner vender

41 Akmel Hasen 62 mud house &fence Dwelling Partial Owner

42 Worknesh Ali 34.5 mud house &fence Dwelling Partial Owner house wife

43 Abdella Hasen 39.5 mud house &fence Dwelling Partial Owner vender

44 Ayelch Megerssa 6.5 fence CIS Dwelling Partial Owner civil serevant

45 Muzeyn Ahmed 13 mud house Dwelling Partial Owner daily laborer

46 Hunde

32 mud house Dwelling Partial Owner daily laborer

47 Nure Musa 27 mud house Dwelling Partial Owner civil serevant

48 Mareguwa Birhanu 17 mud house Dwelling Partial Owner house wife

49 Mebratu Debo 34 mud house Dwelling Partial Owner daily laborer

50 Asmare Ayele 20

Dwelling Partial Owner daily laborer

51 Wudma Debo 19 mud house Dwelling Partial Owner privat gurd

52 Fantaye Lmane 21 mud house Dwelling Partial Owner vender

53 Negash Muzeyn 20 mud house Dwelling Partial Owner small scal ent

54 Gadissie Muleta 21 mud house Dwelling Partial Owner

55 Hailu Bekele 0

Dwelling Partial Owner pension

56 Fanaye Wordofa 24 mud house Dwelling Partial Owner house wife

57 Genanaw Wondimu 18 mud house Dwelling Partial Owner private

58 Endalkachew Dote 17 fence CIS Dwelling Partial Owner business man

59 Ngash Bekele 10 mud house Dwelling Partial Owner pensioner

60 Tesfaye Asule 21 mud house Dwelling Partial Owner private


168


Household number

Name of

household or



construction

Use of the

property

level of effect

(total, partial,

minimum)

Tenure

status

Employment status


61 Mulu Getahun 19 mud house Dwelling Partial Owner house wife

62 Merkebu Kassa 26 mud house Dwelling Partial Owner pensioner

63 Askale Bereda 68 mud house Dwelling Partial Owner business

64 Aselefech Mengiste 36 mud house Dwelling Partial Owner house wife

65 Awgichew Tilaye 0

Dwelling Partial Owner private

66 Megerssa lelissa 161.8 mud house & fence Dwelling Partial Owner civil servant

67 Bizunesh Demissie 66 mud house & fence Dwelling Partial Owner house wife

68 Solomon Bekele 0

Dwelling Partial Owner private com.emp

69 Mkuria Tesema 0

Dwelling Partial Owner business

70 Simur Ayenew 10.2 fence CIS Dwelling Partial Owner civil servant

71 abreham Zeberga 7 fence CIS Dwelling Partial Owner

72 Aynalem Habte 12.6 fence CIS Dwelling Partial Owner house wife

73 Leta

6 fence CIS Dwelling Partial Owner pensioner

74 Nuria Omer 9 fence CIS Dwelling Partial Owner house wife

75 Tariku Tesfaye 7.7


76 Ashenafi Kebede 0


77 Aliye Deremo 12.2 fence CIS Dwelling Partial Owner pensioner

78 Hadosh Baraki 12.5 fence CIS Dwelling Partial Owner business

79 Alemu Taddese 14 fence CIS Dwelling Partial Owner pensioner

80 G/egziabher T/hymamot 0


81 Solomon G/hiwot 0

Dwelling Partial Owner civil servant

82 Takele Beyene 0


83 G/meskel Teklu 14 fence CIS Dwelling Partial Owner Farmer/investor


169


Household number

Name of

household or



construction

Use of the

property

level of effect

(total, partial,

minimum)

Tenure

status

Employment status


84 Yinegrutal Abate 9.3 fence CIS Dwelling Partial Owner private com.emp

85 Netanet Degu 17 mud house Dwelling Partial Owner civil servant

86 Tshome Belay 55.2 mud house & fence hollow block Dwelling Partial Owner NGO

87 Gugsa Mahetem 31 mud house & fence hollow block Dwelling Partial Owner pensioner

88 Nekhewot

15 fence hollow block Dwelling Partial Owner

89 Resom G/Silasse 17 fence hollow block Dwelling Partial Owner daily laborer

90 Tekalgn Werkae 40 mud house & fence hollow block Dwelling Partial Owner NGO

91 Mamite Desta 53 mud house & fence hollow block Dwelling Partial Owner house wife

92 Erkiyhun Ferede 0

Dwelling Partial Owner pensioner

93 Hana Getahun 12.2 fence hollow block Dwelling Partial Owner business w

94 Solomon Hirpa 23.3 fence hollow block Dwelling Partial Owner business

95 Sebsibe H/Mariam 8 fence hollow block Dwelling Partial Owner

96 Tewodros Abate 10 fence hollow block Dwelling Partial Owner private

97 Yared G/medhin 31 mud house Dwelling Partial Owner Student

98 Begashaw Kebede 3.3 fence CIS Dwelling Partial Owner civil servant

99 T/hymanot Berehe 10.3 fence hollow block Dwelling Partial Owner pensioner

100 Teshome Zewdu 11.2 fence hollow block Dwelling Partial Owner p.cmp.emp

101 Kdija mohamed 4 fence CIS Dwelling Partial Owner house wife

102 Zelalem Kassa 4 fence hollow block Dwelling Partial Owner house wife

103 Fikre Adera 8.5 fence hollow block Dwelling Partial Owner civil servant

104 Enkutatash G/Egizeabher 8 fence hollow block Dwelling Partial Owner house wife

105 Tekleab Girma 9 fence hollow block Dwelling Partial Owner private

106 Shewaye Argaw 7 fence hollow block Dwelling Partial Owner house wife


170


Household number

Name of

household or



construction

Use of the

property

level of effect

(total, partial,

minimum)

Tenure

status

Employment status


107 Emebet Tamirat 12 fence hollow block Dwelling Partial Owner

108 H/Mariam Terfa 5.4 fence hollow block Dwelling Partial Owner pensioner

109 known by GPS 17.8 fence hollow block Dwelling Partial Owner

110 Billgn Tamre 0


111 Brahanu Endegena 10 fence hollow block Dwelling Partial Owner civil serevant

112 Zerehane taddese 8 fence hollow block Dwelling Partial Owner

113 Alemzewd Abebe 10.2 fence hollow block Dwelling Partial Owner

114 Yarad Lsanu 9 fence hollow block Dwelling Partial Owner civil servant

115 Solomon Kebede 10.7 fence hollow block Dwelling Partial Owner private

116 Luel Eleas 4 fence hollow block Dwelling Partial Owner private

117 Yeshetela haile 8.7 fence hollow block Dwelling Partial Owner

118 Zenashe Gezahgn 8.5 fence hollow block Dwelling Partial Owner

119 zerfabelen Desta 6.7 fence hollow block Dwelling Partial Owner house wife

120 Getachew Diriba 4.7 fence hollow block Dwelling Partial Owner civil servant

121 Teshome Abebe 6.7 fence hollow block Dwelling Partial Owner civil servant

122 known by GPS 11.5 fence hollow block Dwelling Partial Owner

123 Girma Mulugeta 4.4 fence hollow block Dwelling Partial Owner civil servant

124 Mulu Geleta 8 fence hollow block Dwelling Partial Owner house wife

125 brtukan Geleta 5 fence hollow block Dwelling Partial Owner house wife

126 Lasab Belayneh 8.4 fence hollow block Dwelling Partial Owner house wife

127 Banche Desta 13 fence hollow block Dwelling Partial Owner house wife

128 Bacha Berhe 34.2 mud house & hollow block Dwelling Partial Owner pensioner

129 Bekele Werga 8.1 fence hollow block Dwelling Partial Owner pensioner


171


Household number

Name of

household or



construction

Use of the

property

level of effect

(total, partial,

minimum)

Tenure

status

Employment status


130 Kebede W/mariam 3.8 fence hollow block Dwelling Partial Owner pensioner

131 Demeke Batabe 5 fence hollow block Dwelling Partial Owner civil servant

132 Tadele Sheferaw 7.6 fence CIS Dwelling Partial Owner civil servant

133 Agze Brhanu 11 mud house &fence CIS Dwelling Partial Owner civil servant

134 Tega Tolosa 8 fence CIS Dwelling Partial Owner house wife

135 Wedage Amare 7 fence hollow block Dwelling Partial Owner pensioner

136 Meseret Kebede 22.6 fence hollow block Dwelling Partial Owner civil servant

137 Yrgalem Temesgen 13.3 fence hollow block Dwelling Partial Owner house wife

138 known by GPS 13 fence hollow block Dwelling Partial Owner

139 Kebede Senbeta 8 fence CIS Dwelling Partial Owner private

140 Genet feleke 19 fence hollow block Dwelling Partial Owner house wife

141 Abebe Mekonnen 3 fence hollow block Dwelling Partial Owner private

142 Yeshi Ayele 17 fence hollow block Dwelling Partial Owner civil servant

143 Debebe Bekele 10.5 fence hollow block Dwelling Partial Owner pensioner

144 Dereje Mengesha 3 fence CIS Dwelling Partial Owner private

145 Tegaye W/mariam 6.6


146 Seged woldabe 0

Dwelling Partial Owner no

147 Tizita Tilahun 5 fence hollow block Dwelling Partial Owner no

148 Mengistu Begashaw 8.1 fence hollow block Dwelling Partial Owner no

149 Tilahun Melaku 19 fence hollow block Dwelling Partial Owner

150 Lakew Derbew 63 mud house &fence CIS Dwelling Partial Owner civil servant

151 Abeba Abreha 32 mud house Dwelling Partial Owner house wife

152 Kassahun Asfaw 39 mud house Dwelling Partial Owner private


172


Household number

Name of

household or



construction

Use of the

property

level of effect

(total, partial,

minimum)

Tenure

status

Employment status


153 Yeshigeta Tamre 0


154 Tsega Alebel 75 mud house Dwelling Partial Owner priest

155 Tlaye WALJRA 0

Dwelling Partial Owner private

156 Erbka T/silasse 11 mud house Dwelling Partial Owner house wife

157 Walelu Zewde 34 mud house &fence CIS Dwelling Partial Owner pensioner

158 Abera Kefa 13.7 mud house &fence CIS Dwelling Partial Owner private

159 Alem Dejene 40 mud house &fence CIS Dwelling Partial Owner pensioner

160 Worke Addise 14 mud house Dwelling Partial Owner house wife

161 Kyesha Gnbure 15.8 mud house &fence CIS Dwelling Partial Owner daily laborer

162 Ermiyas Wondmagn 39 fence CIS & HOLLOW BLOCK Dwelling Partial Owner pensioner

163 Maledu Tegabu 9 mud house Dwelling Partial Owner house wife

164 Endalkachew Adnew 20.5 mud house &fence CIS Dwelling Partial Owner business

165 Degfee Agonafer 33.3 mud house &fence CIS Dwelling Partial Owner comp.emp

166 kassa Berehe 16 mud house Dwelling Partial Owner daily laborer

167 Enana Mehret 0

Dwelling Partial Owner house wife

168 Metasebia Tesfaye 16 mud house &fence CIS Dwelling Partial Owner house wife

169 the Biniams Shemels 31 mud house Dwelling Partial Owner Student

170 Desalgn Gebessa 43 mud house &fence CIS Dwelling Partial Owner comp.emp

171 Kitaba Gudeta 74 mud house Dwelling Partial Owner no

172 Dinknesh Begashaw 27 mud house Dwelling Partial Owner comp.emp

173 Konjet Getachew 52 mud house Dwelling Partial Owner

174 Kebebushi H/mariam 52 mud house Dwelling Partial Owner house wife

175 Amare Engdawork 106 mud house Dwelling Partial Owner pensioner


173


Household number

Name of

household or



construction

Use of the

property

level of effect

(total, partial,

minimum)

Tenure

status

Employment status


176 Tena Mengistu 28 mud house &fence CIS Dwelling Partial Owner no

177 Zewdu Tilahun 3 FENCE CIS Dwelling Partial Owner no

178 Zenbech Ayele 56 mud house &fence CIS Dwelling Partial Owner civil servant

179 Ayelu Bedane 42 mud house &fence CIS Dwelling Partial Owner house wife

180 Negusu Mezemer 6 FENCE CIS Dwelling Partial Owner priest

181 Eynesh Weldeyes 29 mud house Dwelling Partial Owner house wife

182 Melese Hasen 70 mud house Dwelling Partial Owner house wife

183 Girma Endeshaw 17 mud house Dwelling Partial Owner priest

184 Yatnesh Welde 75 mud house & HOLLOW BLOCK Dwelling Partial Owner house wife

185 Fikre Husen 85 mud house Dwelling Partial Owner private

186 tegereda Debalk 31 mud house Dwelling Partial Owner private

187 Estifanos G/tadik 50 mud house Dwelling Partial Owner

188 Etenesh Eshete 26 mud house Dwelling Partial Owner house wife

189 Tadese Nega 45 mud house Dwelling Partial Owner pensioner

190 Demitu sory 0


191 zelalem Mengistu 0


192 Taye Abebe 7.75 fence hollow block Dwelling Partial Owner civil servant

193 Tesma Weldeyes 0


194 Bushra Mussa 4.3 fence CIS Dwelling Partial Owner priest

195 Muktar Ahmed 5.7 fence CIS Dwelling Partial Owner house wife

196 Tegaye Teka 0


197 Yonas Taye 45 mud house Dwelling Partial Owner priest

198 Getye Mikre 13 mud house Dwelling Partial Owner house wife


174


Household number

Name of

household or



construction

Use of the

property

level of effect

(total, partial,

minimum)

Tenure

status

Employment status


199 W/gebrail Nrayo 12 fence CIS Dwelling Partial Owner private

200 Tekabech Alemu 31 mud house Dwelling Partial Owner house wife

201 Ngatu Asfaw 18 mud house Dwelling Partial Owner no

202 Ene-Mesfin Alemu 17 fence CIS Dwelling Partial Owner pastor

203 Tamrat Chernt 0 - Dwelling Partial Owner private

204 Ene-Lulet Girma 21 fence CIS Dwelling Partial Owner private

205 Yeshe Bekele 19 fence CIS Dwelling Partial Owner private

206 Zemerkin Dembue 18 fence CIS Dwelling Partial Owner pensioner

207 Yeshareg G/sillassie 0


208 Mengistu Haile 37.5 mud house & hollow BLOCK fence Dwelling Partial Owner pensioner

209 Yirga Desta 0

Dwelling Partial Owner pensioner

210 Ephrem Teklu 12 mud house Dwelling Partial Owner no

211 Alemayehu W/Gebriel 41 mud house Dwelling Partial Owner private

212 Aleme Tefera 10 mud house Dwelling Partial Owner house wife

213 Nebyat Tefera 28 mud house Dwelling Partial Owner private

214 Bayush Teggn 93 mud house &fence CIS Dwelling Partial Owner house wife

215 Mengistu Zewde 0


216 Bereka Eshete 8.3 fence CIS Dwelling Partial Owner house wife

217 Erstu Fantaye 26 fence CIS Dwelling Partial Owner private

218 Tiruye Engdasew 0


219 Molla Getahun 11.6 fence hollow block Dwelling Partial Owner pensioner


221 Mesfin Arega 5.3 fence CIS Dwelling Partial Owner private


175


Household number

Name of

household or



construction

Use of the

property

level of effect

(total, partial,

minimum)

Tenure

status

Employment status


222 Abdrahman Yakobe 8 fence CIS Dwelling Partial Owner private

223 Fantanesh Alemu 38 mud house Dwelling Partial Owner house wife

224 Rede

0

Dwelling Partial Owner contractor

225 Tesfaye H/michiel 77 mud house Dwelling Partial Owner pensioner

226 Bogale(org) Taddese 57 fence CIS& HOLLOW BLOCK Dwelling Partial Owner metal workshop rented

227 Abebe

13.3 fence CIS& HOLLOW BLOCK Dwelling Partial Owner

228 kelemwa Kabthymer 66 mud house Dwelling Partial Owner house wife

229 Onta Mote 83 mud house Dwelling Partial Owner private

230 known by GPS 27 fence CIS Dwelling Partial Owner

231 Hasi Donomam Muzeyim 19 fence CIS Dwelling Partial Owner business

232 Mesfin Alemu 47 fence hollow block Dwelling Partial Owner private

233 Ephrem Gezahgn 0


234 Tensae Birhanu 10.4 fence hollow block Dwelling Partial Owner civil

235 Abu Dabi

0

Dwelling Partial Owner

236 known by GPS 0



238 known by GPS 0


239 Fekadu berta 22 mud house Dwelling Total Owner vender Fully affected

240 Senayt Kifle 17 mud house Dwelling Total Owner house wife Fully affected

241 Aself Haile 19 mud house Dwelling Total Owner vender Fully affected

242 Sheawalem Hasen 23 mud house Dwelling Total Owner vender Fully affected

243 Yeshewaget Teferra 31 mud house Dwelling Total Owner Private Fully affected

244 Zulfa Abdu 17 mud house Dwelling Total Owner House wife Fully affected


176


Household number

Name of

household or



construction

Use of the

property

level of effect

(total, partial,

minimum)

Tenure

status

Employment status


245 Nasir Kedir 24 mud house Dwelling Total Owner daily laborer Fully affected

246 Kamil Sani 34 mud house Dwelling Total Owner vender Fully affected

247 Birhanu Zrgaw 39 mud house Dwelling Total Owner daily laborer Fully affected

248 Triku W/yohans 21 mud house Dwelling Total Owner daily laborer Fully affected

249 Tesema Awgchew 48 mud house Dwelling Total Owner daily laborer Fully affected

250 Girma Worku 30 mud house Dwelling Total Owner Private emp. Fully affected

251 Taddese Zirkwa 21 mud house Dwelling Total Owner daily laborer Fully affected

252 Niri Shifa 22 mud house Dwelling Total Owner vender Fully affected

253 Bambeta Wegeta 17 mud house Dwelling Total Owner vender Fully affected

254 Abera Haile 32 mud house Dwelling Total Owner vender Fully affected

255 Fetiha Mubark 23 mud house Dwelling Total Owner daily laborer Fully affected

256 Tekle sifer 41 mud house Dwelling Total Owner daily laborer Fully affected

257 mohamed Sifer 44 mud house Dwelling Total Owner vender Fully affected

258 mohamed kedir 40 mud house Dwelling Total Owner vender Fully affected

259 Kifle Nemaga 40 mud house Dwelling Total Owner Private emp. Fully affected

260 Tesfaye

25 mud house Dwelling Total Owner daily laborer Fully affected

261 Taddese Ajma 144 mud house Dwelling Total Owner daily laborer Fully affected

262 Bayse Bekele 26 mud house Dwelling Total Owner civil servant Fully affected

263 Tamrat Kebede 38 mud house Dwelling Total Owner private artist Fully affected

264 Belaynesh Kebede 38 mud house Dwelling Total Owner daily laborer Fully affected

265 Ayana Gebre 63 mud house Dwelling Total Owner civil servant Fully affected

266 Shamil yasin 33 mud house Dwelling Total Owner daily laborer Fully affected

267 Mubarek oumer 28 mud house Dwelling Total Owner vender Fully affected


177


Household number

Name of

household or



construction

Use of the

property

level of effect

(total, partial,

minimum)

Tenure

status

Employment status


268 Birhanu Asrat 17 mud house Dwelling Total Owner private Fully affected

269 Tega G/mariam 0 CIS house Dwelling Total Owner private Fully affected

Table A1.2 Affected Businesses

No. Name or type of business Plot area


construction

Use of the

property

level of

effect (total,

partial,

minimum) Tenue status Comments

1 Garage 25 meter fence CIS Business Partial Owner

2 Muez garage 30 meter fence CIS Business Partial Owner

3 plc 22.8 CIS house Business Partial Owner

4 JICA Training center 25 meter fence stone wall Business Partial Owner

5 Agriculturalinputs supp. 12 meter fence stone wall Business Partial Owner

6 Spice factory 757

meter square CIS

STORE&FENCE Business Partial Owner

7 Abdi Garage 405 METER fence IS Business Partial Owner

8 Awash Tannery 125 meter stone wall fence Business Partial Owner

9 Anjela store Business Partial Owner

10 Nfas Silk lafto forest 240 eucalyptus trees Business Partial Owner

11 Bihere Tegy Park 56 eucalyptus trees Business Partial Owner

12 Joint Enterprise coop. 9 eucalyptus trees Business Partial Owner

13 comet transport 450

cis houses &12 meters stone

wall fence Business Partial Owner

14 Defense Construction 6 meter CIS fence Business Partial Owner


178


No. Name or type of business Plot area


construction

Use of the

property

level of

effect (total,

partial,

minimum) Tenue status Comments

15

Agricultural Marketing

enterprise 12 meters stone wall fence Business Partial Owner

16 Mekan yesus workshop 1110

meter squ.CIS STORE

208CUBIC METER FUEL

TANKER Business Partial Owner 25 m3 Septic tank

17 Washed coffee enterprise 12 meter stone wall fence Business Partial Owner

18 Agrisco 12 meter stone wall fence Business Partial Owner

19 Lika plc 19.3 meter hollow block fence Business Partial Owner

20

Nefas Silk lafto district 9

mosque 12 meters CIS fence Business Partial Owner

21 Defense Construction. 12 meter stone wall fence Business Partial Owner

28 m3 fuel tank and 25

m3 septic tank

22 Saudi Arabia embassy 37 meter stone wall fence Business Partial Owner

23 Micro enterprise 78 meter squ.foundation Business Partial Owner

24 Micro enterprise 65 meter squ.foundation Business Partial Owner

25 ETHIO Marble Industry 206 Meter squ.CIS STORE Business Partial Owner

26 MICro enterprise 37

meter squ.FoundationCIS

STORE Business Partial Owner

27 G.A.D construction p.l.c 23 meter fence CIS Business Partial Owner

28 Fetno derash ider 16.3 meter CIS FENCE Business Partial Owner

29 known by GPS 38

METER

SQUA.FUNDATION Business Partial Owner


179


Table: A1.3 Impact caused by displacement (household)

No

.

Name Loss of

land (m3)

loss or

decrease of

income

loss or difficulty

of access to

educational

services

loss of access

to health

loss of access

to public

services

loss of

access

network

Comments

1 Fekadu Berta 22 No No No No No only loss of dwelling mud house

2 Senayt Kifle 17 No No No No No only loss of dwelling mud house

3 Aself Haile 19 No No No No No only loss of dwelling mud house

4 Sheawalem Hasen 23 No No No No No only loss of dwelling mud house

5 Yeshewaget Teferra 31 No No No No No only loss of dwelling mud house

6 Zulfa Abdu 17 No No No No No only loss of dwelling mud house

7 Nasir Kedir 24 No No No No No only loss of dwelling mud house

8 Kamil Sani 34 No No No No No only loss of dwelling mud house

9 Birhanu Zrgaw 39 No No No No No only loss of dwelling mud house

10 Triku W/yohans 21 No No No No No only loss of dwelling mud house

11 Tesema Awgchew 48 No No No No No only loss of dwelling mud house

12 Girma Worku 30 No No No No No only loss of dwelling mud house

13 Taddese Zirkwa 21 No No No No No only loss of dwelling mud house

14 Niri Shifa 43.5 No No No No No Loss of mud house and CIS

15 Bambeta Wegeta 17 No No No No No only loss of dwelling mud house


180


No

.

Name Loss of

land (m3)

loss or

decrease of

income

loss or difficulty

of access to

educational

services

loss of access

to health

loss of access

to public

services

loss of

access

network

Comments

16 Abera Haile 32 No No No No No only loss of dwelling mud house

17 Fetiha Mubark 23 No No No No No only loss of dwelling mud house

18 Tekle sifer 41 No No No No No only loss of dwelling mud house

19 mohamed Sifer 44 No No No No No only loss of dwelling mud house

20 mohamed kedir 40 No No No No No only loss of dwelling mud house

21 Kifle Nemaga 40 No No No No No only loss of dwelling mud house

22 Tesfaye 25 No No No No No only loss of dwelling mud house

23 Taddese Ajma 144 No No No No No only loss of dwelling mud house

24 Bayse Bekele 26 No No No No No only loss of dwelling mud house

25 Tamrat Kebede 38 No No No No No only loss of dwelling mud house

26 Belaynesh Kebede 38 No No No No No only loss of dwelling mud house

27 Ayana Gebre 63 No No No No No only loss of dwelling mud house

28 Shamil yasin 33 No No No No No only loss of dwelling mud house

29 Mubarek oumer 28 No No No No No only loss of dwelling mud house

30 Birhanu Asrat 17 No No No No No only loss of dwelling mud house

31 Tega G/mariam 16 NO NO NO NO NO Los of CIS house sand fence


181


Annex 2. Professionals Involved in the Study

No. Name Academic Rank Specialization Experience

(Yr)

Involvement in the project

1 Tenalem

Ayenew

PhD, Professor Hydro-

geology/Hydrology

25 Hydrology and

hydrogeology, water

quality (Project

Coordinator)

2 Feleke Zewge PhD, Associate

Professor

Environmental

Engineer

20 Wastewater treatment

processes and technology

3 Zebene Kifle PhD, Associate

Professor

Chemical Engineer 24 Wastewater treatment

processes and technology,

report writing impact

assessment evaluation

4 Kasahun Bedane M.Sc Environmentalist 26 Evaluate the biological

environment and

environmental health.

legal and policy

frameworks

5 AmareMekonnen M.Sc Environmentalist 22 Evaluate the physical

environment for the ESIA

6 Teklemarim

Mengestie

M.Sc Sociologist 34 Socioeconomic evaluation

7 Adefris Demise M.Sc Socio-economist 28 Prepare the RAP

8 Almaz Shitie M.Sc Environmentalist 26 Water quality assessment

9 Workneh Tefera Diploma Surveyor 10 Surveying the trunk lines

14 Zewdu

Alebachew

M.Sc GIS expert 7 Prepare maps and spatial

analysis of design

documents


182


Annex 3 Historical water quality records in the project area

N

o. Location of sample's site

P

H

D

O

C

O

D

BO

D5

Susp. Solids Diss. Solids

Se

tt-

la

bl

e

sol

.

TKN

N

H

3

N

O2

-

N

O3

-

C

L-

SO

4-

P

O4

-

Alkal

inity

Gre

ase

Total

ColiFo

rm

Inorg

anic

Orga

inic

Inorg

anic

Orga

inic

Unit

m

g/l

mg

/l

mg/

l mg/l mg/l mg/l mg/l

m

g/l mg/l

m

g/l

mg

/l

mg

/l

m

g/l

mg

/l

mg

/l mg/l

mg/

l

MPN/1

00ml

LITTLE AKAKI &

TRIBUTARIES

1

S.of Rubber shoes fact

debrezeit Rd.

8.

2

NI

L

51

8 399 90 150 714 91

22

0 22.4 58 0

NI

L

10

0 13 6.8 380 NIL

40000

000

3 North west of berehere TSGE

7.

7

0.

3 68 68 6 30 268 16

NI

L NIL

19

.4

0.0

5 1.3 22

NI

L 7.6 180 NIL 32000

4 Near Mekanisa liquor factory

6.

7

5.

7

33

2 478 15 28 489 110 40 4.8

7.

7 0

NI

L 65 45 3 148 NIL

24000

0

5 Near diversion point to swer

7.

6

2.

3

21

1 180 120 90 547 41

21

1 0.8

42

.6

2.6

4 2.2 65

NI

L 9.5 308 NIL

52000

00

6 Near Jima road Tsige

7.

9

0.

6 55 40 NIL NIL 348 11

NI

L 2.5

8.

8

1.1

9 6.2 50 60 5 140 NIL 3100

7

Downstream Akaki bridge on

Jima road

8.

2

0.

8

54

2 339 116 196 678 74

31

2 13.5

32

.3

0.0

3 4.4

11

0 5 9.8 330 NIL

56000

000

1

6 South of Berehe bridge

7.

1

NI

L

31

2 252 73 83 541 59

15

0 13.4

53

.5

NI

L

NI

L 65

NI

L 8 320 NIL

54000

00

1

7

East Paulos&Pestros church-

Ambo road

7.

5

5.

8 7 8 NIL NIL 153 NIL

NI

L NIL 1

1.1

9 1.3 15 3 2.4 100 NIL 18

2

1

South of Gulele soap fact.

Ambo road

8.

1

7.

7 7 3.5 NIL NIL 150 NIL

NI

L NIL

0.

5

0.1

2 0.9 25 2 0.7 76 NIL 240

2

2

North of Gulele soap fact.

Ambo road

7.

9

7.

1 7 3.7 NIL NIL 96 NIL

NI

L NIL

0.

6

0.5

3 2.2 5

NI

L 1.8 68 NIL 9200

2

4

MekaneyesusLidetabrige(Sth.M

ercato)

7.

4

NI

L

51

6 535 98 166 573 152

26

2 34.5 63

NI

L 3.5 83

NI

L 9 375 4.3

95000

000

2

8 Upstr. Kaliti treat. PtConflunet 8

NI

L

38

2 100 80 140 933 173

21

0 27.4

68

.4

NI

L

NI

L

22

5 24 6.5 400 4.6

48000

00

2

9

Down st.Kaliti treat. Pt

Confluent

8.

1

NI

L

41

1 105 90 210 969 236

28

4 44.8

80

.6

NI

L

NI

L

23

5 20 9.6 410 4.5

94000

000

3

0

Upstream Awash Tannery

Effluent

7.

9

NI

L

16

6 102 40 54 479 32

16

3 21.4

42

.6

NI

L

NI

L 60 10 8 236 NIL

52000

000

3

1

Downstream Awash Tannery

Enffluent

8.

2

NI

L

20

2 117 80 110 526 69

22

5 33.7

45

.2

NI

L

NI

L 75 14 8.5 84 5

83000

000

3

2

Upstream Aday Ababa

Enffluent

8.

2

0.

8 86 42 42 52 479 30

14

2 14.3 28

4.9

5 6.6 60 14 11 136 NIL

71000

00

3

3

Downstream Aday Ababa

Enffluent 8

NI

L

10

1 64 40 50 479 30

14

3 14.2

28

.4

5.2

8 6.2 60 14

11.

2 85 NIL

68000

00

3

4

Upstream Awash Winery

Enffluent

7.

8

6.

6 21 12 NIL NIL 259 NIL

NI

L NIL

0.

7

1.5

2

14.

1 35 13 4.6 144 NIL 78000

3

5

Downstream Awash Winery

Enffluent

6.

7

5.

7

34

5 486 16 30 508 118 40 4.9

7.

6

NI

L

NI

L 66 45 3.4 146 NIL

25000

0

3

6 Upstream Abattoirs Enffluent

7.

7

NI

L

46

6 428 360 325 549 112

66

5 34.2

58

.1

0.0

7 3.1 75 4 11 320 5.8

69000

000

3

7

Downstream Abattoirs

Enffluent

7.

6

NI

L

48

5 444 353 364 555 116

68

7 35.6 71

0.0

5 1.8 85 2

13.

2 340 5.4

57000

000

KEBENA & TRIBUTARIES

2 South east of EFTC 8

5.

8 46 35 NIL NIL 442 8

NI

L 7

27

.5 2.6 8.8 38 4 9 276 NIL 12000

8

Kechene behind main post

office

7.

7 2

20

2 134 89 87 429 81

17

6 21

55

.5

NI

L

NI

L 64 15 9.8 230 NIL

32000

00

9 kechene near Zewditu hospital

7.

6 2

21

7 144 150 98 435 65

24

8 22.4

58

.1

0.0

5

NI

L 65 15 10 225 NIL

44000

00

N


P

H

D

O

C

O

D

BO

D5


Se

tt-

la

bl

e

sol

.

Orga

n.N

N

H

3

N

O2

-

N

O3

-

C

L-

SO

4-

P

O4

-

Alkal

inity

Gre

ase

Total

ColiFo

rm

Inorg

anic

Orga

inic

Inorg

anic

Orga

inic

Unit

m

g/l

mg

/l

mg/

l mg/l mg/l mg/l mg/l

m

g/l mg/l

m

g/l

mg

/l

mg

/l

m

g/l

mg

/l

mg

/l mg/l

mg/

l

MPN/1

00ml

KEBENA &

TRIBUTARIES(CONT'D)

1

0 Misrak secondary school

7.

7

3.

7 97 63 52 39 341 24 91 14

38

.7

0.3

8 3.5 45 15 10 184 NIL

53000

00

1 On Bantyiketu downstream 7. 0. 41 184 303 357 512 57 64 20 41 0.0 0.8 48 4 10 330 NIL 86000


183


N


P

H

D

O

C

O

D

BO

D5


Se

tt-

la

bl

e

sol

.

TKN

N

H

3

N

O2

-

N

O3

-

C

L-

SO

4-

P

O4

-

Alkal

inity

Gre

ase

Total

ColiFo

rm

Inorg

anic

Orga

inic

Inorg

anic

Orga

inic

1 Bambi bridge 7 4 0 5 .9 3 000

1

2 Downstream Urael Bole bridge

7.

7

0.

8

12

7 24 58 38 334 10 88 12

30

.7

1.1

9 0.8 46 6 10 180 NIL

12000

00

1

4

South of st Joseph church and

Cemet

7.

9

0.

6 82 48 32 54 446 36 83 17

32

.3

1.0

2 2.6 56 6 8.5 256 NIL 470

1

5 Near Bole bridge 8

0.

6

11

2 60 56 21 489 44 72 17.3

32

.3

0.0

5 0.4 47 5 8.6 326 NIL 38000

1

8

Kurtume B. Zeleke road N.st.

Mary sch.

7.

8 6 4 7 NIL NIL 164 NIL

NI

L NIL

1.

1

1.1

8

12.

3 22 4 4 78 NIL 4600

1

9

kechene near kechene bridge E.

of Univ.

7.

8

4.

8 40 36 NIL NIL 465 NIL

NI

L 4

13

.2

0.5

9 3.5 70 9 9 232 NIL

73000

00

2

0 North of French embassy 8

6.


NI

L NIL

0.

6

0.0

5

10.

1 57 3 2.7 166 NIL

57000

0

2

3

Kechene near st Peter

Tubercul. Hosp.

7.

6

3.

7 26

12.

5 NIL NIL 407 NIL

NI

L 3.5

10

.3

1.6

5 6.2 48

NI

L 6 250 NIL 85000

2

5 KurtumeHabteGiorgis bridge

8.

1

0.

6

13

7 93 42 66 512 35 42 22.7

51

.6

1.4

8 2.2 63 8

11.

2 286 NIL

73000

00

GREAT AKAKI

1

3

Near end of Bole airport

runway

7.

6 1 37 32 NIL NIL 258 18

NI

L 17

21

.3

1.1

8 8.8 35 10 4.8 140 NIL 5

2

6 Near Legadadi

7.

7

7.


NI

L NIL

0.

6

1.1

9 2.6 2 4 2.5 132 NIL 13

2

7

Near by pass bridge (Akaki

city)

7.

8

4.

7 11 10 NIL NIL 306 NIL

NI

L NIL

0.

9

2.9

7

13.

2 22 7 4 184 NIL 3600

ABA SAMUEL LAKE

3

8 Ababa Samuel dam Enffluent

7.

3

6.

7 7 1.2 NIL NIL 320 NIL

NI

L NIL

0.

6 0.1 1.3 50

3.

8 1.8 190 NIL 350

3

9

Aba Samuel (Eastside-1km

from dam) 7

1.

4 7 2.2 NIL NIL 306 NIL

NI

L NIL

0.

6

0.0

7 1.3 48

3.

5 1.8 182 NIL 350

4

0

Aba Samuel (Westside-1km

from dam)

7.

1

3.

8 8 1.3 NIL NIL 300 NIL

NI

L NIL

0.

6 0.1 0.9 50

3.

6 1.6 176 NIL 280

4

1


from dam)

7.

1

1.

8 10 1.3 NIL NIL 332 NIL

NI

L NIL

0.

7

0.0

7 0.9 52

3.

5 1.6 196 NIL 360

4

2


from dam)

7.

1

1.

9 10 1.4 NIL NIL 330 NIL

NI

L NIL

0.

6

0.0

7 0.9 52

3.

5 1.6 198 NIL 230

Hydroensulpide H2S

concentrationis NIL for all tests


184


Annex 4: FAO Guideline for Wastewater Use in Agriculture

Table .A4.1 Recommended microbiological quality guidelines for wastewater use in agriculture

Catego

ry

Reuse condition Exposed

group

Intestinal

nematodesb

(arithmetic

mean no. of eggs

per liter

Faecal coliforms

(geometric mean

no. per 100 ml)

Wastewater treatment

expected to achieve the

required microbiological

quality

A Irrigation of crops likely

to be eaten uncooked,

sports fields, public

parksdd

Workers,

consumer

s, public

1 1000d A series of stabilization

ponds designed to achieve

the microbiological quality

indicated, or equivalent

treatment

B Irrigation of cereal crops,

industrial crops, fodder

crops, pasture and treese

Workers 1 No standard

recommended

Retention in stabilization

ponds for 8-10 days or

equivalent helminth and

faecal coliform removal

C Localized irrigation of

crops in category B if

exposure of workers and

the public does not occur

None Not applicable Not applicable Pretreatment as required by

the irrigation technology,

but not less than primary

sedimentation

Table A4.2 Guidelines forinterpretation of water quality for irrigation

Potential irrigation problem Units

Degree of restriction on use

None Slight to moderate Severe

Salinity

Ecw1 dS/m < 0.7 0.7 - 3.0 > 3.0

or

TDS mg/l < 450 450 - 2000 > 2000

Infiltration

SAR2 = 0 - 3 and ECw

> 0.7 0.7 - 0.2 < 0.2

3 -6

> 1.2 1.2 - 0.3 < 0.3

6-12

> 1.9 1.9 - 0.5 < 0.5

12-20

> 2.9 2.9 - 1.3 < 1.3

20-40

> 5.0 5.0 - 2.9 < 2.9

Specific ion toxicity

Sodium (Na)

Surface irrigation SAR < 3 3 - 9 > 9

Sprinkler irrigation me/I < 3 > 3

Chloride (Cl)

Surface irrigation me/I < 4 4 - 10 > 10

Sprinkler irrigation m3/l < 3 > 3 11

Boron (B) mg/l < 0.7 0.7 - 3.0 > 3.0

Trace Elements

Miscellaneous effects

Nitrogen (NO3-N)3 mg/l < 5 5 - 30 > 30

Bicarbonate (HCO3) me/I < 1.5 1.5 - 8.5 > 8.5

pH Normal range 6.5-8


185


1 ECw means electrical conductivity in deciSiemens per metre at 25°C 2 SAR means sodium adsorption ratio 3 NO3-N means nitrate nitrogen reported in terms of elemental nitrogen

Source: FAO(1985)

Table A4.3 Threshold levels of trace elements for production

Element Recommended

maximum

concentration

(mg/l)

Remarks

Al (aluminum) 5.0 Can cause non-productivity in acid soils (pH < 5.5), but more alkaline soils at

pH > 7.0 will precipitate the ion and eliminate any toxicity.

As (arsenic) 0.10 Toxicity to plants varies widely, ranging from 12 mg/l for Sudan grass to less

than 0.05 mg/l for rice.

Be (beryllium) 0.10 Toxicity to plants varies widely, ranging from 5 mg/l for kale to 0.5 mg/l for

bush beans.

Cd (cadmium) 0.01 Toxic to beans, beets and turnips at concentrations as low as 0.1 mg/l in

nutrient solutions. Conservative limits recommended due to its potential for

accumulation in plants and soils to concentrations that may be harmful to

humans.

Co (cobalt) 0.05 Toxic to tomato plants at 0.1 mg/l in nutrient solution. Tends to be inactivated

by neutral and alkaline soils.

Cr (chromium) 0.10 Not generally recognized as an essential growth element. Conservative limits

recommended due to lack of knowledge on its toxicity to plants.

Cu (copper) 0.20 Toxic to a number of plants at 0.1 to 1.0 mg/l in nutrient solutions.

F (fluoride) 1.0 Inactivated by neutral and alkaline soils.

Fe (iron) 5.0 Not toxic to plants in aerated soils, but can contribute to soil acidification and

loss of availability of essential phosphorus and molybdenum. Overhead

sprinkling may result in unsightly deposits on plants, equipment and buildings.

Li (lithium) 2.5 Tolerated by most crops up to 5 mg/l; mobile in soil. Toxic to citrus at low

concentrations (<0.075 mg/l). Acts similarly to boron.

Mn (manganese

)

0.20 Toxic to a number of crops at a few-tenths to a few mg/l, but usually only in

acid soils.

Mo (molybden

um)

0.01 Not toxic to plants at normal concentrations in soil and water. Can be toxic to

livestock if forage is grown in soils with high concentrations of available

molybdenum.

Ni (nickel) 0.20 Toxic to a number of plants at 0.5 mg/l to 1.0 mg/l; reduced toxicity at neutral

or alkaline pH.

Pd (lead) 5.0 Can inhibit plant cell growth at very high concentrations.

Se (selenium) 0.02 Toxic to plants at concentrations as low as 0.025 mg/l and toxic to livestock if

forage is grown in soils with relatively high levels of added selenium. As

essential element to animals but in very low concentrations.

Sn (tin)

Ti (titanium) - Effectively excluded by plants; specific tolerance unknown.

W (tungsten)

C (vanadium) 0.10 Toxic to many plants at relatively low concentrations.

Zn (zinc) 2.0 Toxic to many plants at widely varying concentrations; reduced toxicity at pH

> 6.0 and in fine textured or organic soils.

1 The maximum concentration is based on a water application rate which is consistent with good

irrigation practices (10 000 m3 per hectare per year). If the water application rate greatly exceeds

this, the maximum concentrations should be adjusted downward accordingly. No adjustment should


186


be made for application rates less than 10 000 m3 per hectare per year. The values given are for water

used on a continuous basis at one site.


187


ANNEX 5: USEPA, NPDES AND EC EDR for discharges from wastewater treatment

plants

A significant element in waste-water disposal is the potential environmental impact associated with

it. Environmental standards are developed to ensure that the impacts of treated waste-water

discharges into ambient waters are acceptable. Standards play a fundamental role in the

determination of the level of wastewater treatment required and in the selection of the discharge

location and outfall structures.

Regulations and procedures vary from one country to another and are continuously reviewed and

updated to reflect growing concern for the protection of ambient waters. In Ethiopia, there is no well

established guideline and standard for the discharge of wastewater into water bodies. The United

States Environmental Protection Agency (USEPA) developed the National Pollutant Discharge

Elimination System (NPDES) permit programme in 1972 to control water pollution by regulating

point sources that discharge pollutants into waters. Accordingly, industrial, municipal, and other

facilities are required to obtain permits if their discharges go directly into surface waters. Under this

programme, secondary treatment standards were established by USEPA for publicly owned

treatment works (POTWs), governing the performance of secondary waste-water treatment plants.

These technology-based regulations, which apply to all municipal waste-water treatment plants,

represent the minimum level of effluent quality attainable by secondary treatment in terms of BOD5

and TSS removal as presented in the following table.

Table A5.1 USEPA, NPDES AND EC EDR FOR DISCHARGES FROM WASTEWATER TREATMENT PLANTS


188


Annex 6Environment, Health and Safety Aspects of the Project

Workers in every occupation can be faced with a multitude of hazards at the workplace.

Occupational health and safety addresses the broad range of workplace hazards from accident

prevention to the more insidious hazards including toxic fumes, dust, noise, heat, stress, etc.

Preventing work- related diseases and accidents must be the goal of occupational health and safety

programs/activities rather.

Hazards in workplace manifest themselves in a variety of forms, including chemical, physical,

biological, psychological, non-application of ergonomic principles, etc. Therefore, appropriate

consideration must be given during the design and implementation stages of the development

project in order to eliminate or reduce work place hazards associated with the project thereby

ensuring the health and safety of workers. Most effective hazard preventions begin in the design

stage of the proposed activities.

The type and level of hazards are generally related to controllable factors such as workplace design,

installations, equipment, tools, processes, work procedures, raw materials, byproducts, and the

degree and sophistication of employees’ training. Administrative and managerial facilities generally

involve less risks and hazards than industrial settings.

A6.1 Environment/Ambient Factors

Noise

Noise limits for different working environments are given in Table A7.1. No employee may be

exposed to a noise level greater than 85 dB(A) for a duration of more than 8 hours per day. In

addition, no unprotected ear should be exposed to a peak sound pressure level (instantaneous) of

more than Leq,fast 110 dB(A). The use of hearing protection must be actively enforced where Leq,8h

reach 85 dB(A). In the project activities, where such conditions are present, the Contractor or the

Client should avail hearing protection to workers.

Table A6.1 Noise limits Leq, 8h and maximum Lmax, fast

Location/activity Equivalent noise level

Leq,8h

Maximum noise level

Lmax,fast

Heavy industry 85 dB(A) 110 dB(A)

Light industry 50-60 dB(A) 110 dB(A)

Open offices, control

rooms, service counters or

similar

45.-50 dB(A) -

Individual offices 40-45 dB(A) -

Hospitals 30.35 dB(A) 40 dB(A)

Vibration

Exposure to hand-arm vibration from equipment such as hand and power tools or whole body

vibrations from surfaces on which workers stand or sit shall be controlled through selection of


189


equipment and limitation of exposure time. The limitation for vibration and action values, i.e. the

level of exposure at which remediation should be initiated are given in Table A7.2.

Table A6.2 Vibration exposure and action value limits (acceleration, m/s2)

Description Hand-arm vibration Whole-body vibration

Daily exposure limit value

standardized to 8hs reference period

5m/s2

1.15m/s2

Daily exposure action value

standardized to 8hs reference period

2.5m/s2

0.6m/s2

Illumination

Work area light intensity must be adequate especially in the operation period of the WTP, for the

general purpose of the location and type of activity and must be supplemented with dedicated

workplace illumination as required. All light sources should be with minimum heat emission.

Reflection from flickering light/glare should be avoided at work place.

Temperature

Indoor temperatures that are conducive and appropriate for the type of work shall be ensured. Risks

of heat or cold related stress must be adequately addressed and feasible control measures

implemented for the work in adverse environment. This is important in areas where digesters and

burners (flaring) are present, i.e., in the WTP.

Hazardous substances

Handling, storage, transportation and disposal of hazardous substances such as chemicals, gases,

vapors, fumes, dust, fibers, etc. shall fulfill the requirements of the national and international

standard guidelines. One or more of these substances will be used by the project.

Therefore, the Hazardous Materials Management Plan should address applicable, essential elements

of occupational health and safety management including:

Job safety analysis to identify specific potential occupational hazards and industrial hygiene

surveys, as appropriate, to monitor and verify chemical exposure levels, and compare with

applicable occupational exposure standards

Hazard communication and training programs to prepare workers to recognize and respond

to workplace chemical hazards. Programs should include aspects of hazard identification,

safe operating and materials handling procedures, safe work practices, basic emergency

Precaution must be taken to keep the risk of exposure to hazardous substance as low as possible.

Work processes, engineering and administrative control measures must be designed, maintained and

operated so as avoid or minimize the release of hazardous substances into the working environment.

The number of employees exposed or likely to become exposed must be kept at a minimum and the

level of exposure maintained below internationally established or recognized exposure limits. When

hazardous materials are in use above threshold quantities, the management plan should include a


190


system for community awareness, notification and involvement that should be commensurate with

the potential risks identified for the project during the hazard assessment studies.

Air emissions and ambient Air Quality

Emissions of air pollutants can occur from a wide variety of activities during the construction,

operation, and decommissioning phases of the project. The sources are mainly point sources,

fugitive sources, and mobile sources.

Where possible, facilities and projects should avoid, minimize, and control adverse impacts to

human health, safety, and the environment from emissions to air. Where this is not possible, the

generation and release of emissions of any type should be managed through a combination of

different methods such as process modification, and application of emissions control techniques.

Projects with significant sources of air emissions, and potential for significant impacts to ambient

air quality, should prevent or minimize impacts by ensuring that emissions do not result in pollutant

concentrations that reach or exceed relevant ambient quality guidelines and standards by applying

national legislated standards, or in their absence, the current WHO Air Quality Guidelines (see

Table A7.3).

Table A6.3 WHO Ambient Air Quality Guidelines

Point Sources

Point sources in the project include digesters, flaring apparatus, standby diesel generator.


191


Stack Height

The stack height for all point sources of emissions, whether ‘significant’ or not, should be designed

according to GIIP to avoid excessive ground level concentrations.

Fugitive Sources

The two main types of fugitive emissions are Volatile Organic Compounds (VOCs) and particulate

matter (PM). Other contaminants (NOx, SO2 and CO) are mainly associated with combustion

processes, as described above. Projects with potentially significant fugitive sources of emissions

should establish the need for ambient quality assessment and monitoring practices.

Open burning of solid wastes, whether hazardous or nonhazardous, is not considered good practice

and should be avoided, as the generation of polluting emissions from this type of source cannot be

controlled effectively.

Particulate Matter (PM)

The most common pollutant involved in fugitive emissions is dust or particulate matter (PM). This is

released during construction operations, transportation, material handling, open storage of solid

materials, and from exposed soil surfaces, including unpaved roads. Recommended prevention and

control of these emissions sources include:

Use of dust control methods, such as covers, water suppression, or increased moisture

content for open materials storage piles, or controls, including air extraction and treatment

through a baghouse or cyclone for material handling sources, such as conveyors and bins;

Use of water suppression for control of loose materials on paved or unpaved road surfaces.

Oil and oil by-products is not a recommended method to control road dust. Examples of

additional control options for unpaved roads include those summarized in Table A7.4.

Land-based Mobile Sources

Similar to other combustion processes, emissions from vehicles include CO, NOx, SO2, PM and

VOCs. Emissions from on-road and off-road vehicles should comply with national or regional

programs. In the absence of these, the following approach should be considered:

Regardless of the size or type of vehicle, fleet owners / operators should implement the

manufacturer recommended engine maintenance programs;

Drivers should be instructed on the benefits of driving practices that reduce both the risk of

accidents and fuel consumption, including measured acceleration and driving within safe

speed limits.

Emissions from Wastewater Treatment Operations

Air emissions from wastewater treatment operations may include hydrogen sulfide, methane. Odors

from treatment facilities can also be a nuisance to workers and the surrounding community.


192


Wastewater and Ambient Water Quality

Projects with the potential to generate process wastewater, sanitary (domestic) sewage, or

stormwater should incorporate the necessary precautions to avoid, minimize, and control adverse

impacts to human health, safety, or the environment. In the context of their overall ESHS

management system, facilities should assess compliance of their wastewater discharges with the

applicable water quality standard for a specific reuse for irrigation.

Table A6.4 Fugitive PM Emissions Control

Waste management

Facilities that generate and store wastes should practice the following:

Establishing waste management priorities at the outset of activities based on an

understanding of potential Environmental, Health, and Safety (EHS) risks and impacts and

considering waste generation and its consequences

Establishing a waste management hierarchy that considers prevention, reduction, reuse,

recovery, recycling, removal and finally disposal of wastes.

Avoiding or minimizing the generation waste materials, as far as practicable

Where waste generation cannot be avoided but has been minimized, recovering and reusing

waste

Where waste cannot be recovered or reused, treating, destroying, and disposing of it in an

environmentally sound manner


193


Hazardous Materials Management

Hazardous materials can be classified according to the hazard as explosives; compressed gases,

including toxic or flammable gases; flammable liquids; flammable solids; oxidizing substances; toxic

materials; radioactive material; and corrosive substances.

The overall objective of hazardous materials management is to avoid or, when avoidance is

not feasible, minimize uncontrolled releases of hazardous materials or accidents (including

explosion and fire) during their production, handling, storage and use.

Projects which manufacture, handle, use, or store hazardous materials should establish

management programs that are commensurate with the potential risks present. The main

objectives of projects involving hazardous materials should be the protection of the

workforce and the prevention and control of releases and accidents.

A 6.2 Occupational Health and Safety

Building and structures

Buildings and structures should be designed and constructed in accordance with the national and

international health and safety requirements. Surface structures and installations should be easy to

clean and maintain, and should not favor for the accumulation of hazardous substances. Buildings

must be structurally safe, provide appropriate protection against the climate and noise conditions

and have acceptable light. Fire resistance, noise absorbing materials should, to the extent feasible,

be used for cladding on ceilings and walls. Floor should be level, even, and non-skid. Heavy

oscillating and rotating equipment should be located in dedicated buildings or structurally isolated

sections.

The workplace must be adequate for each worker for safe execution of all activities including

transport, interim storage of materials and products. Passages to emergency exits must be free of

obstruction/obstacle at all times. The number and capacity of emergency exits must be sufficient for

safe and orderly evacuation of the people present at any time.

Confined Spaces

Engineering measures must be implemented to eliminate, to the extent possible, the existence and

adverse effects of confined space. Unfavorable confined space must be provided with permanent

safety measures for venting, lighting, monitoring, and rescue operations. The area adjoining an

access to a confined space should provide ample room for emergency and rescue operations.

Access

Passageways for pedestrians and vehicles should be segregated and provided for easy, safe and

appropriate access. Equipment and installations requiring recurrent servicing and cleaning should be

provided with adequate permanent means of access. Hand, knee, and foot railings must be installed


194


on stairs, fixed ladders, platforms, permanent and interim floor openings, loading bays, ramps, etc.

Coves shall, if feasible, be installed to protect against falling items.

Installations, equipment, tools, and substances

Installations, equipment, tools and substances shall be appropriate and suitable for use and with

minimum or no health and safety hazards. Appropriate shields, guards, or railings must be installed

and maintained to avoid human contact with moving parts, or hot and cold items. Equipment must

be provided with adequate noise and vibration dampers. Electrical installations must be designed,

constructed and maintained to eliminate fire or explosion hazards and risk to the employees.

Safety signs

Hazardous and risky areas, installations, materials, and safety measures, emergency exits, etc. shall

be appropriately marked. Signs shall be in accordance with the international standards, be well

known to, and easily understood by the workers, visitors, and the general public as appropriate.

Lighting

As far as possible, natural light should reach workplaces and be supplemented with sufficient

artificial illumination to maintain and improve workers safety and health. Emergency lighting of

adequate intensity must be installed and automatically activated upon failure of the artificial light

source to ensure safe shut-down, evacuation, etc.

Ventilation and temperatures

Sufficient fresh air must be supplied for indoor and confined workplaces. Factors to be considered

in the design of a ventilation system include physical activity, substance handled and process

emissions. Mechanical ventilation systems shall be maintained in good working condition. Point-

source exhaust systems required for maintaining a safe ambient environment must have local

indicators for correct functioning. Air inlet filters must be maintained and be clean and free of dust.

Air distribution systems must be designed to avoid exposure of employees to undesirable draughts.

The temperature in work and rest rooms, and other welfare facilities should, during service hours,

be maintained at a level appropriate for the purpose of the facility.

Fire detection and fire fighting

Workplaces must be equipped with fire detectors, alarm systems and fire-fighting equipment. The

equipment shall be maintained in proper working conditions. It should be adequate for the available

facilities, physical and chemical properties of substances present. Non-automatic fire-fighting

equipment must be easily accessible and simple to use in the event of fire. Fire and emergency

alarm systems shall be both audible and visible.

First-aid

Appropriately equipped first-aid stations shall be provided and be easily accessible throughout

workplaces. Eye-wash stations and/or emergency showers must be provided close to all


195


workstations where the recommended first-aid response is immediate flushing with water

particularly in case of contacting corrosive substances. First-aid stations and rooms shall be

provided with gloves, gowns, and masks for protection against direct contact with blood and other

body fluids.

Sanitary and welfare facilities

Washbasins with running hot and cold water shall be installed in sufficient numbers as demanded

by the character of the work and where contaminants or pollutants are released and confined in

workplaces. Adequate supply of drinking water shall be ensured for all workers. Water supplies

shall be conveniently located especially for areas of high physical activities. Drinking water

supplies shall be clearly marked especially where non-potable water is also available.

Welfare facilities including locker rooms and adequate number of toilets with washbasins, and room

dedicated for eating free of any possible contamination should be provided. Separate eating

facilities need to be provided for employees wearing clean and soiled working clothes, respectively.

Gender-segregated changing rooms with lockers should be provided when special work-clothes are

required. Hot and cold water shower facilities and washbasins should be available close to the

locker rooms.

Separate lockers must be installed for isolating street-cloth from work-cloth when the circumstances

(dirt, dangerous substances etc.) so require for employees exposed to hazardous conditions to avoid

contamination.

Personal protective equipment (PPE)

Employees shall be provided with appropriate personal protective equipment that will offer/serve

appropriate personal protection. The use of protective equipment shall be actively enforced by the

management unless the hazards are eliminated or sufficiently reduced through technological or

procedural change.


196


Annex 7. Format for asset survey along the sewerlines

Kaliti WASTE WATER TREATMENT REAHABILITATION PROJECT

AFFECTED INDIVIDUALS, LAND RESOURCES, STRUCTURES AND ORGANIZATIONS

SOCIO-ECONOMIC SURVEY DATA SHEET

GPS Position: X________________Y_______________ Z__________ Date____________

I. General

1.1Household head name_________________2.Father's name: ___________3.Mother'sname ____

1.2 Age ________________

1.3 Sex: 1. Male 2. Female

1.4 Occupation ____________________ 1.5 Religion _________________________

1.6 Address: Sub-city____________________ Wereda_______ House no. ____

1.7Family size: 1. Males _________ 2. Females ______________ 3. Total ______________

1.8 Education: Pre-school 1st

cycle primary 2nd

cycle primary

Secondary College preparatory College

1.9 Is the family head or is there a family member with disability? 1) Yes 2) No

II. Type of property affected:

2.1 Type of housing:

Type Size (m2) Height (m)

2.2 Hollow blocks with corrugated iron sheet _________ ________

2.3 Mud with corrugated iron sheet _________ ________

2.4 Stonewall with corrugated iron sheet __________ ________

2.5 Mud house with grass roof ___________ _________

2.6 All with corrugated iron sheet _____________ ___________

2.6 Septic tank Meter cube ___________ _________

2.7 Ownership:

2.7.1 Rented from Kebele

2.7.2 Rented from individual Owner’s Name: ______________________________

2.7.3 My Own Ownership title number ________________

2.7.4 Noownership title

2.8 Use:

2.8.1 Dwelling

2.8.2 Business Type of business____________; monthly income from business (birr) _________

Additional observations/Remarks_________________________________________________________

_____________________________________________________________________________________

_____________________________________________________________________________________


197


2.9 Fence

2.9.1 Stonewall meter length ____________ meter thickness____________

2.9.2 Corrugated iron sheet meter_____________

2.9.3 Wood meter__________________

2.9.4 Hollow block

2.9.4 Other ______________________________________________

Additional observations/Remarks_________________________________________________________

_____________________________________________________________________________________

____________________________________________________________________________________

____________________________________________________________________________________

2.10 Number and type of affected crops and trees

2.10.1 Type of crop____________, land in hectare (harvested/covered)________Yield (Qt/ha)________ Production in

Qt___________________

2.10.2 Type of tree_____________, Number of tree: Big ________, Medium ______, Small __________

2.10.3 Type of fruit tree_____________, Age of tree__________, Productivity in Kg._____________, Cost for land

improvement (Birr)____________, Cost to grow_______________

2.11 Affected pubic infrastructure

2.11.1 Telecommunications: 1. number of poles____________ 1. Number of p.b.x_________

2.11.2 Electric: 1. Number of high tension power poles ______2. Number of normal poles ________

2.11.3Asphalt road: __________meter by ___________meter= ____________square meters

2.11.4 Coble stone road: ____________meter by _________meter = ___________square meters

2.11.5 Gravel road : ____________ meter by __________meter= __________square meters

Additional observations/Remarks________________________________________________________

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E1566 V4 - World Bank Documents & Reports

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