EIA for development drilling of hydrocarbons at Khoraghat ...

EIA for development drilling of hydrocarbons at Khoraghat Extension ML Block

Draft EIA Report

Prepared for:

Oil and Natural Gas Corporation Limited

Prepared by:

SENES Consultants India Pvt. Ltd.

December 2013


SENES/K-20199/ December 2013 b ONGC

DRAFT REPORT

Oil and Natural Gas Corporation Limited

EIA for development drilling of

hydrocarbons at Khoraghat Extension ML

Block

For on and behalf of SENES Consultants India Ltd

Approved by Mr. Salil Das

Signed by

Position held NABET-QCI Accredited EIA Coordinator

for Offshore & Onshore Oil and Gas

Exploration Development and Production

Date December 10th

2013

The EIA report preparation have been undertaken in compliance with the approved ToR

issued by MoEF vide letter no. ToR vide letter J-11011/563/2011-IA II (I) dated 28th

May,

2012.Information and content provided in the report is factually correct for the purpose and

objective for such study undertaken.


SENES/K-20199/ December 2013 c ONGC

Abbreviation

ALARP As Low As Reasonably Practicable

BOD Biological Oxygen Demand

BOP Blow out Preventor

Block Khoraghat Extension ML Block

Cd Cadmium

CGWB Central Ground Water Board

COD Chemical Oxygen Demand

CPCB Central Pollution Control Board

Cr Chromium

CSR Corporate Social Responsibility

Cu Copper

DG Diesel Generator

DGH Directorate General of Hydrocarbons

DMP Disaster Management Plan

DO Dissolved Oxygen

EC Environmental Clearance

EIA Environmental Impact Assessment

EMP Environment Management Plan

ETP Effluent Treatment Plant

FC Forest Clearance

GGS Group Gathering Station

GLC Ground Level Concentrations

GoI Government of India

HC Hydrocarbon

HDPE High Density Polyethylene

HSD High Speed Diesel

HSE Health, Safety and Environmental

IMD Indian Meteorological Department

IUCN International Union for Conservation of Nature & Natural Resources

KLD Kilo Liter per Day


SENES/K-20199/ December 2013 d ONGC

KW Kilo Watt

MoEF Ministry of Environment and Forests

NAAQS National Ambient Air Quality Standards

NABET National Accreditation Board for Education and Training

NABL National Accreditation Board for Testing and Calibration Laboratories

NELP New Exploration Licensing Policy

NH National Highway

NOx Oxides of Nitrogen

OCS Oil Collection Station

O&G Oil & Gas

ONGC Oil and Natural Gas Corporation Limited

OSHA Occupational Safety and Health Administration

Pb Lead

PEL Petroleum Exploration License

PM Particulate Matter

PPE Personnel Protective Equipments

PSC Production Sharing Contract

PUCC Pollution Under Control Certificate

QCI Quality Council of India

QRA Quantitative Risk Assessment

RF Reserved Forest

SO2 Sulphur Dioxide

SPCB State Pollution Control Board

SPL Sound Pressure Level

TDS Total Dissolved Solid

TG Tea Garden

TSS Total Suspended Solids

VOC Volatile Organic Compound

WBM Water Based Mud

WLS Wild Life Sanctuary


SENES/K-20199/ December 2013 i ONGC

Executive Summary

INTRODUCTION

The Khoraghat Extension ML Block part of Assam-Arakan Basin is located in Golaghat

District of Assam. Oil and Natural Gas Corporation Limited (ONGC) plans to drills two

development wells in Khoraghat Extension ML Area. ONGC already has existing facilities

like production wells, two Group Gathering Stations (GGS) and interconnecting pipelines in

the Block.

SENES Consultants India Pvt. Ltd. (SENES) a NABET-QCI Accredited firm has been

entrusted to conduct an Environmental Impact Assessment (EIA) for the proposed activities

in the Khoraghat Extension ML Block. The EIA study comprised of initial scoping & site

visit, environmental monitoring & surveys, preparation of draft EIA-EMP report for Public

Hearing (PH).

PROJECT DESCRIPTION

Block Location & Accessibility

Khoraghat Extension ML area is 83 square kilometer and located in Golaghat District,

Assam, close to Nagaland Hills. The Block is flanked by Dayang River flowing in the East

and Rengma River through the central part of the Block. The confluence of Dayang and

Rengma lies at the north of the Block. The Block is topographically represented in Survey of

India’s 83 M/3, 83 M/7 and 83 M/11 toposheets. Three wells (KHDD, KHDE and KHDF) are

proposed to be located in Haldhibari village. KHDD and KHDE will be drilled at new

locations in agricultural fields and KHDF is proposed to be drilled at an existing facility of

Khoraghat GGS-1 of ONGC.

The Khoraghat ML Block can be accessed by road from the district town of Golaghat. The

route is via NH-36 till Shilanijan and then via. rural roads through Barpathar, Sarupathar,

Uriamghat and finally to the site. Sarupathar is the nearest railway station (approx. 24 km)

and is part of North-East Frontier Railways connecting Guwahati with Dibrugarh. The closest

Airport is at Dimapur, Nagaland, approximately 60 km from the Block.

Land Lease

The Khoraghat ML Block is located on forest lands of Dayang Reserve Forest and Rengma

Reserve Forest. Approximately 2.25 hectare of land will be required per drill sites and an

approximate 0.02 ha is required for approach road for KHDD and KHDE. Both the proposed

development wells are located at Rengma Reserve Forest. Entire forest land in the block is

encroached and presently used for agricultural practices. As per Forest (Conservation) Act

1980, ONGC will take forest clearance from Center/State for diversion of forest land. ONGC

has already obtained permission for the conversion of Forest land for KHDF drill site, which

is located within existing Khoraghat GGS-1. Applications for the conversion of forest land

for the new development well sites KHDD and KHDE has already been submitted to the

Forest Department.


SENES/K-20199/ December 2013 ii ONGC

Since the forest land is used for agricultural purpose, ONGC will give the crop compensation

as ONGC’s policy of leasing land. On the culmination of the activities, the land will be

restored to its original state and returned to their previous users.

Project Activities

This activity involves

well site preparation, construction of access roads,

Well drilling and testing.

Site closure and decommissioning of wells not indicative of potential hydrocarbon

reserves.

Construction Drill site

Both the drill sites are connected with site access road. A small approach road needs to be

constructed for KHDE drill site. The construction of drill site will involve top soil scraping

and storage for future use, elevating the drill platform by locally available fill material,

construction of High Density Polyethylene (HDPE) lined pits for storage of drill cutting,

waste mud and drilling wash water, construction of suitable storm water drainage system with

oil trap.

Drilling & Testing

The drilling of the wells is expected to be up to a depth of 2500 meters. Standard Land Rig

or Mobile Land Rig with standard water based drilling fluid treatment system will be used for

drilling. Drill cuttings generated will be collected and separated using a solid control system

and temporarily stored on-site in HDPE lined pits. Drilling and wash wastewater generated

will also be stored at an onsite HDPE lined pit. The water will be adequately treated in a

mobile Effluent Treatment Plant (ETP) to ensure conformance to the CPCB onshore oil and

gas extraction industry effluent standards before disposal.

Site closure and decommissioning

The drill sites will be properly reclaimed and rehabilitated if no commercial reserve has been

established. This process will involve decommissioning of rigs and all machineries; disposal

of drilling waste as per CPCB guidelines, disposal of fill materials, top soil restoration.

Project Utilities and Resource Requirements

Power

The power requirement for each drill sites will be met through the DG sets. One DG set of

750 KW will be used during site construction. Two DG sets of 750 KW will be

simultaneously operable and one will be kept as standby during drilling operation and one for

lighting and other power requirements. It is estimated that 6 KLD of diesel will be required

during drilling phase alone. Reserve Fuel will be stored as per Petroleum Rules 2002.


SENES/K-20199/ December 2013 iii ONGC

Water

Water demand during peak construction period is estimated to be 5KLD for construction and

3 KLD for workers at each well site. During the drilling operation, water requirement at site

to meet the industrial requirements is 20 KLD. Total water requirement at each well site

during drilling activities is estimated to be 1200 KL, considering a total of 60 days of drilling

operation (including testing & contingency period). The water requirement at the drilling

sites during construction and drilling phase will be met through procurement of

surface/ground water from approved local sources/suppliers and partly through re-cycling of

treated water from ETP.

Manpower

During peak construction phase (including site preparation), approximately 40-50 personnel

will be engaged including skilled and unskilled labour at each well site. Both locals and

labours from outside will be engaged depending on skills and project requirements.

25-30 personnel will be employed at the drill site at each shift. Provisions for drinking water

and water for other purposes, sewage disposal will be provided at drill site and campsite.

Kitchen facility will be provided at the campsite.

Pollution Sources and Characterization

Noise

Construction equipments and drilling activities generate noise ranging from 79-103 dBA.

Air Emissions

DG set, fugitive dust emission and flaring activities are the major sources of air pollution.

Liquid Waste

9KLD of Drilling and Wash Wastewater and 2.4KLD of Domestic wastewater will be

generated peak drilling period.

Solid and Hazardous Waste

The major solid waste generated during peak drilling period will be 212-225m3of mud

cuttings.

BASELINE ENVIRONMENTAL STATUS

The study of the baseline environmental status helps in assessing the existing environmental

conditions and identifying the critical environmental attributes. The study of the physical,

biological and socio-economic environment of the Block and an area within a radius of 10

km from two development wells (study area) comprises of the baseline environment. Primary

and secondary data were collected for conducting the EIA study.


SENES/K-20199/ December 2013 iv ONGC

Physical Environment

Climate and Meteorology

The study area experiences a humid and warm sub-tropical climate throughout the year

except for a cold winter in December till February. Hourly micro-meteorological data

collected during the pre-monsoon reveals that the pre-dominant wind direction is from South-

East with an average speed of 0.80 m/s.

Air Quality

The ambient air quality representing Particulate Matter (PM10), Sulfur Dioxide (SO2),

Nitrogen Dioxide (NO2) was monitored at eight different locations for 24 hours twice a week

during April-June, 2013.Volatile Organic Carbons (VOCs), Methane (CH4), non-methane

hydrocarbons (NMHCs) were monitored once a week for the same period. All the parameters

were found to be below the National Ambient Air Quality Standards (NAAQS), 2009. The

average 24 hourly PM10 at the monitoring locations ranged between 50.21-70.07µg/m3

(NAAQS-100 µg/m3). The average 24 hourly NO2 at the monitoring locations ranged

between 19.79-24.21 µg/m3

(NAAQS-80 µg/m3). The average 24 hourly SO2 at the

monitoring locations were found to below 4µg/m3

(NAAQS-80 µg/m3). Mean values for

methane and non-methane hydrocarbon ranged between 1.29-2.9 ppm and 0.2-0.7 ppm,

respectively. Mean values of VOC varied between 0.55-2.9 ppm.

Noise Quality

The noise quality was monitored for 24 hours at eight locations close to the drill sites. The

ambient noise quality at day and night was in compliance to the Noise Limits set for the

residential area as per Noise Pollution (Control and Regulations), 2000. The maximum

daytime noise level was detected at 46dBA and the maximum nighttime noise level was

detected at 37dBA.

Physiography

The Khoraghat Block lies in the Brahmputra Valley, drained by Dayang and Rengma rivers.

The Block comprises of alluvial deposits of the rivers that flows down from Naga Patkoi

range. The land slopes from South to North. A continuous belt of piedmont and foothills

extends all along the southern margin of the study area that is undulating in nature.

Geology

The Block lies on different formations of Neogene (Moran, Tipam and Bokabil) and

Paleogene (Barails, Kopili, Sylhet and Tura) sequences. The pay sands are mainly confined

between Barial top conformity and an erosional surface above lower Bokabil.

Hydrogeology

The unconsolidated formations of the sandstone, shale, limestone including conglomerate of

the Coenozoic, Mesozoic and Upper Paleozoic era in the Brahmaputra Basin are significant


SENES/K-20199/ December 2013 v ONGC

ground water reservoirs. The cumulative thickness of aquifer zones has the tendency to

increase towards the North and southeastern parts. The potential yield of groundwater from

tubewell extending to a depth of 30-50m ranges from 30 to 35m3/hr. and the yield from the

deep tubewell varies from place to place depending on the aquifer. As calculated by Central

Ground Water Board, the total annual groundwater draft is 22143 of which 19751ham is

expended for irrigation and 2391ham for domestic and industrial purposes.

Groundwater Quality

Groundwater was collected and analysed as per IS: 10500 from four locations in the study

area. All the parameters analysed was under the acceptable and permissible limit of IS: 10500

except turbidity and iron that was found to be high in all the samples. Heavy metals were

found to be below detection limit. Faecal coliform was detected in the two samples collected

from dug wells.

Watershed and Drainage

The Block lies in the watershed of Dhansiri River. River Dayang (tributary of Dhansiri River)

and Rengma (tributary of Dayang River) are the Principle Rivers that drains the Block.

Surface Water Quality

Surface water was sampled from upstream and downstream of Dayang and Rengma Rivers.

The water samples were analysed and compared with the Designated Best Use Classification

of Surface Waters as per CPCB. The quality of Dayang River (upstream and downstream)

was found suitable for Class A as the total coliform ranged between 9-14 MPN/100ml, pH

ranged between 6.8-7.4, DO ranged between 3.5 and 6.7 mg/l and BOD was less than 2mg/l

except for 1 sample of Rengma river. The water quality of River Rengma upstream is suitable

for Class B as DO is less than 5.4 and total coliform count is 80 MPN/100ml whereas water

quality at downstream is suitable for Class E as pH is 6.8, EC is 137.75 micromhos/cm, SAR

is 0.64 and Boron is less than 1mg/l.

Land Use

The Khoraghat ML Block is included under the Dayang Reserve Forest and Rengma Reserve

Forest. Currently the forested areas are deforested and used for agricultural activities and

human habitation.

The Block land cover data showed majority of the land (about 64%) in the area is used for

agriculture purpose with paddy as the primary produce. Settlements comprise about 33% of

the total area of the Block. River Rengma and Dayang comprise of 1.3% of the total Block

area. Drill pads, GGS etc. facilities of ONGC comprise 0.05% of the total area.

Soil Quality

Primarily two types of soil – Inceptisol (Old alluvial) and Entisols (Recent Alluviums) can be

seen in Golaghat District. The primary analyses of the soil sampled from agricultural field at

5 locations in the study area shows that the soils are acidic in nature, either sandy loam or


SENES/K-20199/ December 2013 vi ONGC

clayey, high in available nitrogen content. The micronutrient levels observed in the soil

samples do not indicate any extraordinary enrichment of metals or contamination from any

external sources.

Natural Hazards

The study area lies in Zone V of the Bureau of Indian Standard (BIS) 2000 which might

encounter earthquakes of maximum intensity. Floods are common in the few parts of the

Khoraghat Extension ML Block but not at locations proximal to the proposed activities.

Biological Environment

The Khoraghat Extension ML Block lies in the Rengma, Dayang and Nambor Reserve Forest

areas. The reserve forests within the Khoraghat Extension ML Block have totally lost its tree

cover due to extensive deforestation. Presently the whole area is under cultivation and not a

single tree will be felled for the proposed activities. However, Golaghat district is rich in

biodiversity and has a number of ecologically sensitive areas like wildlife sanctuaries,

National Parks and Elephant Reserves. None of these ecological habitats lie within the study

area and hence will not be impacted by the Project.

Socioeconomic Environment

Golaghat District in Assam has 1125 villages under eight administrative Blocks. As per 2011

Census, the total population of the district is 1,058,674 with a percent decadal growth rate of

11.88. The sex ratio of is 961 and the population density is 305.

Socioeconomic profile

Twenty three villages within the study area were selected for developing the socioeconomic

profile of the area. It was seen from the Census Data of 2001, Bidyapur Village has the

highest population (1555 persons). The overall demography shows that the 0.02% and

14.65% of the population of the study area villages belongs to Scheduled Caste and

Scheduled Tribe, respectively. The highest literacy rate (74.68%) was observed in Majgaon

and the least was found in Madhupur No.2 (14.31%). The total working population varies

from 15.60% (Chetiagon No.2 Village) to 69.77% (Majhgaon Village). Mono-cropping is

practiced in the study area where 74% of the population depends on agriculture.

Socioeconomic Infrastructure

The socioeconomic infrastructures of the Golaghat district as per 2011 District Handbook

have been outlined here. There is 1 Civil Hospital, 1 sub-divisional hospital, 38 Primary

health Centers, 1 first Referral Units, 5 Community Health Center and 144 sub centers. There

are 864 Primary, 194 Middle and 173 Secondary and 23 Senior Secondary Schools. Drinking

water facility exists in the premises of 46.1% of households. Power supply is present in

36.6% of households.


SENES/K-20199/ December 2013 vii ONGC

On consultation with the local people, the following facts were revealed

Primary schools are present in almost all the villages in the study area

Majority of the people are farmers, the area is mostly monocropped and paddy is the

major crop

Electrical connection is present in all the villages though frequent power failure has

been reported

Dugwell forms the major source of groundwater

Villagers are not satisfied with the health facility as the tertiary referral center is less

in this District

ENVIRONMENTAL IMPACT ASSESSMENT

The potential impacts of the project on different components of the environment was

systematically identified and evaluated for significance. The principal concerns that emerged

are:

Impact on Air Quality

The operation of DG sets, movement of vehicles and machineries during construction and

drilling at drill sites will result in the generation of air pollutants viz. PM, NOx and SOx which

may affect the ambient air quality temporarily. Air pollutants like NOx will also be generated

as a result of flaring of natural gas.

Impact on Noise Quality

Operation of heavy machinery/equipments and vehicular movement during site preparatory

and road strengthening/construction activities may result in the generation of increased noise

levels. Operational phase noise impacts are anticipated from operation of drilling rig and

ancillary equipment viz. shale shakers, mud pumps and diesel generators.

Impact on Soil Quality

Stripping of top soil will affect the soil fertility of the well sites. Potential impact on soil

quality may result from storage and handling of fuel, lubricants and from storage and

handling of drilling mud and drill cuttings.

Impact on Topography and drainage

Elevating the land to about 1 m from the ground level during site preparation may lead to

alteration of onsite micro-drainage pattern. This might lead to the flow of untreated waste

water and excess rain water to the adjoining agricultural land thereby adversely impacting the

fertility of the soil.

Impact on Water Quality and Hydrology

The surface run off from drilling waste (cuttings and drilling mud), hazardous waste (waste

oil, used oil etc) and chemical storage facilities on open soil is likely to contaminate if


SENES/K-20199/ December 2013 viii ONGC

allowed to flow into nearby water bodies viz. natural drainage channels, ponds etc. Possibility

of contamination of subsurface and unconfined aquifers may exist if the casing and

cementing of the well is not carried out properly leading to infiltration or seeping of drilling

chemicals or mud into porous aquifer region.

Impact on Biological Environment

There is no demarcated and sensitive wildlife habitat or Schedule I species within the Block

or its adjacent area. The area is free from any migratory route or corridors (daily and seasonal

movement) for animals. However, noise generated from drilling activities, lighting at well

site, traffic movement will cause of disturbance to local fauna.

Impact on Socio economic Environment

The proposed well site KHDD and KHDE is located in land currently used for agricultural

(monocropped) purpose. ONGC will take this land through private negotiation. Necessary

payments will be made against purchase and crop compensation to concerned land owners.

As the proposed well KHDF will be located within the existing GGS land procurement would

not take place. The proposed project would not require any displacement of villagers.

The project will benefit the people living in the neighboring villages by giving preference to

them in relation to direct & indirect employment associated with the various project activities

and boosts the local economy. The proposed project will therefore involve the improvement

of existing road and/or bridge condition thereby enabling the transportation of drilling rig and

ancillary equipment.

Quantitative Risk Assessment

The quantitative risk assessment has been done to provide a systematic analysis of the major

risks associated with onshore development drilling activities in Khoraghat Extension ML

Block. Oil spills, loss of well control/blow-out and process leaks constitute the major

potential hazards of onshore drilling. Based on Frequency Analysis Method, it has been

estimated that the likelihood of a blowout is Occasional/Rare at a rate of 2.25X10-2

.

Even on blowout, the probability of ignition is approximately 0.0015% i.e. negligible. The

consequence analysis of Blowout assessed by using ALOHA shows settlements like

Chetanapur and part of Haldhibari that are close to KHDE and KHDF might be impacted by

pool fire and natural gas release.

ENVIRONMENTAL MANAGEMENT PLAN

Site-specific Environment Management Plans (EMP) has been developed to prevent and

mitigate significant adverse impacts and accentuate beneficial impacts will be implemented

by ONGC for the proposed project. The key mitigation measures specific for each

management plan have been discussed in the Table below:


SENES/K-20199/ December 2013 ix ONGC

Sl.

No

Environment

Management

Plan

Key Mitigation Measures

1 Pollution

Prevention and

Abatement Plan

The top soil generated from site clearance activities will be stored in

designated area and stabilized to prevent fugitive dust emissions

Preventive maintenance of DG sets to be undertaken as per

manufacturers schedule to ensure compliance with Sl No 95 GSR

371(E) dated 17.5.2002.

All vehicles, equipment and machinery used for construction will be

subjected to preventive maintenance as per manufacturer norms.

Flaring will be undertaken in accordance with the CPCB Guidelines

S No. 72 B. for Discharge of Gaseous Emissions for Oil & Gas

Extraction Industry.

High combustion efficiency, smokeless flare/burner will be used.

Installation of acoustic enclosures and mufflers on engine exhaust of

DG sets to ensure compliance with generator noise limits specified

by Sl No 94 GSR 371(E) dated 17.5.2002.

Effective noise barrier at the fence-line of the sites.

Install and maintain effective run-off controls, including silt traps,

straw barriers etc so as to minimize erosion.

Fuel and chemical storage areas will be paved and properly bunded.

Proper casing and cementing of drilling well will be done to prevent

contamination of sub-surface aquifers.

Water based mud to be used as a drilling fluid or else eco-friendly

synthetic based mud in necessary conditions

2 Waste

Management Plan

Use of low toxicity chemicals for the preparation of drilling fluid.

Management of drill cuttings, waste drilling mud, waste oil and

domestic waste will be made in accordance with S No. 72 C.1.a

Schedule I Standards for Emission or Discharge of Environmental

Pollutants from Oil Drilling and Gas Extraction Industry of CPCB as

modified in 2005Necessary spill prevention measures viz. spill kit

will be made available at the hazardous material storage area

The hazardous waste (waste and used oil) will be managed in

accordance with Hazardous Waste (Management, Handling &

Transboundary Movement) Rules, 2008

The hazardous waste so stored (not more than 3 months) to be

periodically sent to ASPCB registered used and/or waste oil

recyclers/ facilities.

Proper manifest as per HWMH Rules, 2008 to be maintained during

storage

The kitchen waste will be disposed in nearest municipal dumping

site on a daily basis through approved waste handling contractors

The sewage generated will be treated in a combination of septic tank

and soak pit.

Used batteries will be recycled through the vendors supplying lead

acid batteries as required under the Batteries (Management &


SENES/K-20199/ December 2013 x ONGC

Sl.

No

Environment

Management

Plan


Handling) Rules, 2001.

Recyclables will be periodically sold to local waste recyclers.

3 Wild Life

Management Plan

The drill site will be properly fenced (chain-linked) to avoid straying

of any outsider as well as wildlife;

No temporary electric supply connection line from the grid will be

laid for the proposed project activity. All electric requirements will

be supplied from the internal DG sets.

Noise Levels at the drill site will be controlled through selection of

low noise generating equipment and installation of sufficient

engineering controls viz. mufflers, silencers etc.

Movement of heavy vehicles will be restricted at night time

4 Road Safety &

Traffic

Management Plan

Project vehicular movement involved in sourcing and transportation

of borrow material will be restricted to defined access routes.

Precautions will be taken to avoid damage to the public access routes

including highways during vehicular movement.

Clear signs, flagmen & signal will be set up at major traffic junctions

and near sensitive receptors viz. primary schools in discussion with

Gram Panchayat and local villagers.

Movement of vehicles during night time will be restricted. Speed

limits will be maintained by vehicles involved in transportation of

raw material and drilling rig.

A Traffic Management Plan will be formulated and implemented by

the contractor to control construction and operational phase traffic.

Routine maintenance of project vehicles will be ensured to prevent

any abnormal emissions and high noise generation.

Adequate training on traffic and road safety operations will be

imparted to the drivers of project vehicles. Road safety awareness

programs will be organized in coordination with concerned

authorities to sensitize target groups viz. school children, commuters

on traffic safety rules and signage.

5 Occupational

Health & Safety

Management Plan

All machines to be used in the construction will conform to the

relevant Indian Standards (IS) codes, will be kept in good working

order, will be regularly inspected and properly maintained as per IS

provisions and to the satisfaction of the site Engineer.

Contractor workers involved in the handling of construction

materials viz. borrow material, cement etc. will be provided with

proper PPEs viz. safety boots, nose masks etc.

No employee will be exposed to a noise level greater than 85 dB(A)

for a duration of more than 8 hours per day. Provision of ear plugs,

ear muffs etc. and rotation of workers operating near high noise

generating areas.

All chemicals and hazardous materials storage container will be

properly labeled and marked according to national and


SENES/K-20199/ December 2013 xi ONGC

Sl.

No

Environment

Management

Plan


internationally recognized requirements and standards. Materials

Safety Data Sheets (MSDS) or equivalent data/information in an

easily understood language must be readily available to exposed

workers and first-aid personnel.

The workplace must be equipped with fire detectors, alarm systems

and fire-fighting equipments. Equipments shall be periodically

inspected and maintained to keep good working condition.

Adequate sanitation facilities will be provided onsite for the

operational workforce both during construction and operational

phase of the project.

Training programs will be organized for the operational workforce

regarding proper usage of PPEs, handling and storage of fuels and

chemicals etc.

6 Management of

Social issues and

concerns

People from adjoining areas especially given job preference through

local contractors according to the skill sets possessed.

Prior to the commencement of the proposed activity, a consultation

program will be conducted by ONGC with the target groups and

local authorities. The primary objective of such consultation will be

to share with the concerned villagers/stakeholders the objective of

the proposed project associated impacts and their mitigation.

ONGC will give more emphasis and priority on periphery

development, development of health facilities and provision for

drinking water facility as per Corporate Social Responsibility (CSR)

Plan.

During the drilling phase and for the rest of the project activities

proper safety measures will be undertaken both for transportation as

well as the other operations.

The drill site would be fenced and gates would be constructed so that

the children are refrained from straying into the site.

7 Emergency

Response Plan

Drilling rig and related equipments to be used for development

drilling will be conformed to international standards specified for

such equipment.

Blow-out preventers and related well control equipment shall be

installed, operated, maintained and tested generally in accordance

with internationally recognized standards.

Appropriate gas and leak detection system will be made available at

each of the drilling location.

Adequate fire-fighting equipment shall be provided at each drilling

site

Sl.

No

Environment

Management

Plan


1 Pollution

Prevention and


designated area and stabilized to prevent fugitive dust emissions.


SENES/K-20199/ December 2013 xii ONGC

Sl.

No

Environment

Management

Plan


Abatement Plan Preventive maintenance of DG sets to be undertaken as per

manufacturers schedule to ensure compliance with CPCB specified

generator exhaust.



Flaring will be undertaken in accordance with the CPCB Guidelines

for Discharge of Gaseous Emissions for Oil & Gas Extraction

Industry.


Installation of acoustic enclosures and mufflers on engine exhaust of

DG sets to ensure compliance with generator noise limits specified

by CPCB.

Setup effective noise barrier at the fence-line of the site.


straw barriers etc so as to minimize erosion.


Run-off discharges to natural drainage channels/water bodies to

conform to CPCB Inland Water Discharge Standards.

Proper casing and cementing of drilling well will be done to prevent

contamination of sub-surface aquifers.

Water based mud to be used as a drilling fluid

2 Waste

Management Plan


Storage of drill cuttings in impervious HDPE lined pits

Disposal of drilling wastewater will be achieved either through solar

evaporation or necessary treatment to comply with the CPCB

onshore effluent discharge standard for oil and gas industry.

Necessary spill prevention measures viz. spill kit will be made

available at the hazardous material storage area

The hazardous waste (waste and used oil) will be managed in

accordance with Hazardous Waste (Management, Handling &

Transboundary Movement) Rules, 2008

The hazardous waste so stored (not more than 3 months) to be

periodically sent to ASPCB registered used and/or waste oil

recyclers/ facilities.

Proper manifest as per HWMH rules to be maintained during storage

The kitchen waste will be disposed in nearest municipal dumping

site on a daily basis through approved waste handling contractors

The sewage generated will be treated in a combination of septic tank

and soak pit.

Used batteries will be recycled through the vendors supplying lead

acid batteries as required under the Batteries (Management &



SENES/K-20199/ December 2013 xiii ONGC

Sl.

No

Environment

Management

Plan


Recyclables will be periodically sold to local waste recyclers.

3 Wild Life

Management Plan

The drill site will be properly fenced (chain-linked) to avoid straying

of any outsider as well as wildlife;

No temporary electric supply connection line from the grid will be

laid for the proposed project activity. All electric requirements will

be supplied from the internal DG sets.

Noise Levels at the drill site will be controlled through selection of

low noise generating equipment and installation of sufficient

engineering controls viz. mufflers, silencers etc.


In case of any accidental injuries to any wild animal by any project

related activity, a Veterinary Doctor’s help will be taken

4 Road Safety &

Traffic

Management Plan

Project vehicular movement involved in sourcing and transportation

of borrow material will be restricted to defined access routes.

Precautions will be taken to avoid damage to the public access routes

including highways during vehicular movement.

Clear signs, flagmen & signal will be set up at major traffic junctions

and near sensitive receptors viz. primary schools in discussion with

Gram Panchayat and local villagers.

Movement of vehicles during night time will be restricted. Speed

limits will be maintained by vehicles involved in transportation of

raw material and drilling rig.

A Journey Management Plan will be formulated and implemented by

the contractor to control construction and operational phase traffic.

Routine maintenance of project vehicles will be ensured to prevent

any abnormal emissions and high noise generation.

Adequate training on traffic and road safety operations will be

imparted to the drivers of project vehicles. Road safety awareness

programs will be organized in coordination with concerned

authorities to sensitize target groups viz. school children, commuters


5 Occupational

Health & Safety

Management Plan

All machines to be used in the construction will conform to the

relevant Indian Standards (IS) codes, will be kept in good working

order, will be regularly inspected and properly maintained as per IS

provisions and to the satisfaction of the site Engineer.

Contractor workers involved in the handling of construction

materials viz. borrow material, cement etc. will be provided with

proper PPEs viz. safety boots, nose masks etc.

No employee will be exposed to a noise level greater than 85 dB(A)

for a duration of more than 8 hours per day. Provision of ear plugs,

ear muffs etc. and rotation of workers operating near high noise

generating areas.

All chemicals and hazardous materials storage container will be


SENES/K-20199/ December 2013 xiv ONGC

Sl.

No

Environment

Management

Plan


properly labeled and marked according to national and

internationally recognized requirements and standards. Materials

Safety Data Sheets (MSDS) or equivalent data/information in an

easily understood language must be readily available to exposed

workers and first-aid personnel.

The workplace must be equipped with fire detectors, alarm systems

and fire-fighting equipments. Equipments shall be periodically

inspected and maintained to keep good working condition.

Adequate sanitation facilities will be provided onsite for the

operational workforce both during construction and operational

phase of the project.

Training programs will be organized for the operational workforce

regarding proper usage of PPEs, handling and storage of fuels and

chemicals etc.

6 Management of

Social issues and

concerns

People from adjoining areas especially given job preference through

local contractors according to the skill sets possessed.

Prior to the commencement of the proposed activity, a consultation

program will be conducted by ONGC with the target groups and

local authorities. The primary objective of such consultation will be

to share with the concerned villagers/stakeholders the objective of

the proposed project associated impacts and their mitigation.

ONGC will give more emphasis and priority on periphery

development, development of health facilities and provision for

drinking water facility as per Corporate Social Responsibility

(CSR) Plan.

During the drilling phase and for the rest of the project activities

proper safety measures will be undertaken both for transportation as

well as the other operations.

The drill site would be fenced and gates would be constructed so that

the children are refrained from straying into the site.

7 Emergency

Response Plan

Drilling rig and related equipments to be used for development

drilling will be conformed to international standards specified for

such equipment.

Blow-out preventers and related well control equipment shall be

installed, operated, maintained and tested generally in accordance

with internationally recognized standards.

Appropriate gas and leak detection system will be made available at

each of the drilling location.

Adequate fire-fighting equipment shall be provided at each drilling

site


SENES/K-20199/ December 2013 xv ONGC

The EMP has been designed with a flexibility so that it can be monitored and adapted to future

changes in project design, scope, or the environment and be seamlessly integrated and

implemented by ONGC.

Project Cost

An estimated Rs.75 Crore INR will be expended for the drilling of three development wells.

The budget for implementation of the Environment Management Plans is 0.34 crores.


SENES/K-20199/ December 2013 i ONGC

Table of Contents

1 Introduction ....................................................................................................................1

1.1 Background ....................................................................................................................1

1.2 Objective of the Study ...................................................................................................1

1.3 Scope of the Study .........................................................................................................2

1.4 Structure of the EIA report ............................................................................................2

2 Project Description.........................................................................................................7

2.1 Overview ........................................................................................................................7

2.2 Objectives and Benefits of Proposed Development Drilling Activities ........................7

2.3 Block Location ...............................................................................................................7

2.4 Accessibility ...................................................................................................................8

2.5 Khoraghat Extension ML Block ..................................................................................13

2.5.1 Environmental Settings of the Block ...........................................................................13

2.5.2 Salient Features ............................................................................................................13

2.5.3 Existing Activity in Oil Field .......................................................................................16

2.5.4 Environmental Compliance .........................................................................................16

2.6 Well Locations and Environmental Settings................................................................16

2.6.1 Location of Wells .........................................................................................................16

2.6.2 Environmental Settings ................................................................................................16

2.7 Project Activities and Schedule ...................................................................................21

2.7.1 Pre-drilling Activity .....................................................................................................21

2.7.2 Drilling Activity ...........................................................................................................24

2.7.3 Well Decommissioning ................................................................................................29

2.8 Utilities & Resource Requirements .............................................................................30

2.8.1 Power Supply ...............................................................................................................30

2.8.2 Fuel Consumption ........................................................................................................30

2.8.3 Water Consumption and Supply ..................................................................................31

2.8.4 Effluent Treatment .......................................................................................................32

2.8.5 Manpower / Employment ............................................................................................32

2.9 Pollution Sources and Characterization .......................................................................33

2.9.1 Noise and Vibrations....................................................................................................33

2.9.2 Air Emissions ...............................................................................................................34

2.9.3 Liquid Wastes ..............................................................................................................34

2.9.4 Solid and Hazardous Waste Streams ...........................................................................35

2.10 Drilling Hazards ...........................................................................................................35


SENES/K-20199/ December 2013 ii ONGC

2.11 Project Cost ..................................................................................................................36

2.12 HSE Policy ...................................................................................................................36

3 Description of the Environment ...................................................................................37

3.1 Physical Environment ..................................................................................................37

3.1.1 Climate & Meteorology ...............................................................................................37

3.1.2 Ambient Air Quality ....................................................................................................40

3.1.3 Ambient Noise Quality ................................................................................................44

3.1.4 Physiography and Geology ..........................................................................................47

3.1.5 Hydrogeology ..............................................................................................................49

3.1.6 Ground Water Quality..................................................................................................49

3.1.7 Watershed and Drainage ..............................................................................................56

3.1.8 Surface Water Quality..................................................................................................58

3.1.9 Land-Use ......................................................................................................................60

3.1.10 Soil Quality ..................................................................................................................63

3.1.11 Natural Hazards ...........................................................................................................67

3.2 Biological Environment ...............................................................................................70

3.2.1 Introduction ..................................................................................................................70

3.2.2 Methodology ................................................................................................................70

3.2.3 Primary Survey ............................................................................................................71

3.2.4 Terrestrial Ecosystem...................................................................................................72

3.2.5 Floral Diversity ............................................................................................................73

3.2.6 Endemic, Threatened & Endangered Floral Species ...................................................73

3.2.7 Wildlife Habitat ...........................................................................................................74

3.2.8 Faunal Distribution ......................................................................................................79

3.2.9 Endemic, Endangered & Threatened Fauna ................................................................79

3.2.10 Aquatic Ecosystem.......................................................................................................80

3.3 Agricultural Diversity ..................................................................................................81

3.4 Livestock ......................................................................................................................81

3.5 Socioeconomic Environment .......................................................................................82

3.5.1 Methodology ................................................................................................................82

3.5.2 General Socioeconomic Profile ...................................................................................83

3.5.3 Demographic Profile ....................................................................................................84

3.5.4 Socioeconomic Infrastructure ......................................................................................86

3.6 Cultural and Historical Sites ........................................................................................88

4 Environmental Impact Assessment ..............................................................................89


SENES/K-20199/ December 2013 iii ONGC

4.1 Impact Assessment Methodology ................................................................................89

4.1.1 Impact Criteria and Ranking ........................................................................................89

4.1.2 Impact Significance .....................................................................................................90

4.2 Impact Assessment.......................................................................................................93

4.2.1 Visual Impacts & Aesthetics ........................................................................................93

4.2.2 Impacts on Air Quality.................................................................................................94

4.2.3 Impact on Noise Quality ............................................................................................101

4.2.4 Potential Impact Transport and Traffic ......................................................................103

4.2.5 Potential Impact on Land Use ....................................................................................104

4.2.6 Impact on Soil Quality ...............................................................................................105

4.2.7 Impact on Topography & Drainage ...........................................................................107

4.2.8 Impact on Surface Water Quality ..............................................................................108

4.2.9 Impact on Hydrogeology & Ground Water Quality ..................................................109

4.2.10 Impact on Biological Environment ............................................................................110

4.2.11 Impact on Socioeconomic Environment ....................................................................111

4.2.12 Impact on Occupational Health and Safety ...............................................................114

5 Quantitative Risk Assessment (QRA) .......................................................................116

5.1 Objective of the QRA Study ......................................................................................116

5.2 Risk Assessment Methodology ..................................................................................117

5.2.1 Hazard Identification .................................................................................................118

5.2.2 Frequency Analysis ....................................................................................................119

5.2.3 Consequence Analysis ...............................................................................................120

5.2.4 Risk Evaluation ..........................................................................................................122

5.3 Risk Assessment of Identified Project Hazards .........................................................123

5.3.1 Blow Outs/Loss of Well Control ...............................................................................123

5.4 Disaster Management Plan ........................................................................................138

5.4.1 Objective ....................................................................................................................138

5.4.2 Purpose .......................................................................................................................139

5.4.3 Emergency Classification ..........................................................................................139

5.4.4 Level 1 - Emergency ..................................................................................................140

5.4.5 Level 2 - Emergency ..................................................................................................140

5.4.6 Level 3 - Emergency ..................................................................................................141

5.4.7 ONGC Disaster Management Plan ............................................................................141

6 Environmental Management Plan & Monitoring Framework ...................................151

6.1 Environment Management Plans ...............................................................................153


SENES/K-20199/ December 2013 iv ONGC

6.1.1 Pollution Prevention and Abatement Plan (PPAP) ....................................................153

6.1.2 Waste Management Plan............................................................................................158

6.1.3 Site Closure Plan ........................................................................................................162

6.1.4 Storm Water Management Plan .................................................................................163

6.1.5 Wildlife Management Plan ........................................................................................164

6.1.6 Road Safety & Traffic Management Plan ..................................................................165

6.1.7 Occupational Health & Safety Management Plan .....................................................167

6.1.8 Management of Social Issues and Concerns ..............................................................168

6.2 EMP Budget ...............................................................................................................169

6.3 Environmental Monitoring Program ..........................................................................175

7 Disclosure of Consultants ..........................................................................................181


SENES/K-20199/ December 2013 v ONGC

List of Tables

Table 1-1: Compliance to MoEF ToR .......................................................................................3

Table 2-1: Coordinates of the Khoraghat Extension ML Block ................................................8

Table 2-3: Coordinates of Tentative Well Locations ...............................................................16

Table 2-4: Power requirement Break Ups ...............................................................................30

Table 2-5: Water Requirement Per Well .................................................................................31

Table 2-6: Typical Noise Emissions from Construction Machinery .......................................33

Table 2-7: Drilling Rig & Equipment Noise Levels ................................................................33

Table 2-8: Liquid Wastes Generated during Drilling and their Disposal ................................34

Table 2-9: Waste Streams Generated during Drilling and Their Disposal ..............................35

Table 3-1: Average Hydrocarbon and VOC Monitoring Data ................................................43

Table 3-2: Groundwater monitoring Results ...........................................................................53

Table 3-3: Surface Water Quality Results ...............................................................................59

Table 3-4: Soil Analysis Results ..............................................................................................65

Table 3-5: Significant Earthquakes in Assam ..........................................................................67

Table 3-6: Flood history of Assam ..........................................................................................68

Table 3-7: Scheduled Animal Species in the Study Area ........................................................80

Table 3-8: List of the Study Area Villages in the Block ..........................................................85

Table 3-9: Educational Facilities of Golaghat District ............................................................87

Table 4-1: Impact Prediction Criteria ......................................................................................90

Table 4-2: Criteria based Significance of Impacts ...................................................................91

Table 4-3: Impact Identification Matrix ..................................................................................92

Table 4-4: Input Parameters Considered for Monitoring .........................................................95

Table 4-5: Predicted GLCs for Air Pollutants .........................................................................96

Table 4-6: Impact Significance Matrix (with mitigation) ......................................................115

Table 5-1: Frequency Categories And Criteria ......................................................................120

Table 5-2: Severity Categories and Criteria ...........................................................................121

Table 5-3: Risk Matrix ...........................................................................................................122

Table 5-4: Risk Criteria and Action Requirements................................................................122

Table 5-5: Blow Out Cause Distribution for Failures during Drilling Operations ................125

Table 5-6: Pool Fire Modeling Scenarios ..............................................................................128

Table 5-7: Pool Fire Diameter & Steady State Burning Area ...............................................129

Table 5-8: Distance to Thermal Radiation Threshold Levels ................................................132

Table 5-9: Natural Gas Release Modeling Scenarios ............................................................133

Table 5-10: Zone of Flammable Vapour Cloud – Natural Gas Release Scenarios ...............136


SENES/K-20199/ December 2013 vi ONGC

Table 5-11: Pool Diameter for Oil Spill Risk Scenarios........................................................137

Table 5-12: ONGC On-Site Disaster Management Team Profile ........................................143

Table 6-1: Tentative Budget for EMP Implementation .........................................................169

Table 6-2: Environmental Management Matrix ....................................................................172

Table 6-3: Proposed Monitoring Requirements of the Project ..............................................176

List of Figures

Figure 2-1: Regional Setting Map of Khoraghat Extension ML Block .....................................9

Figure 2-2: Khoraghat Extension ML Block on Toposheet .....................................................10

Figure 2-3: Khoraghat Extension ML Block on Satellite Imagery ..........................................11

Figure 2-4: Khoraghat Extension ML Block Accessibility Map .............................................12

Figure 2-5: Environmental Settings of Khoraghat Extension ML Block ...............................15

Figure 2-6: Location of Proposed Wells ..................................................................................20

Figure 2-7: Typical Drilling Rig Configuration.......................................................................25

Figure 2-8: Typical Drilling Fluid Circulation System ............................................................27

Figure 2-9: Drilling Waste Management .................................................................................28

Figure 2-10: Water Balance Diagram ......................................................................................32

Figure 3-1: Wind Rose Diagram for Pre-Monsoon Season .....................................................39

Figure 3-2: Wind Class Frequency Distribution ......................................................................39

Figure 3-3: Average NO2 Values at the Monitoring Locations ..............................................42

Figure 3-4: Average NO2 Values at the Monitoring Locations ...............................................43

Figure 3-5: Day and Night Time Equivalent Noise Levels .....................................................45

Figure 3-6: Location of Air, Noise, Meteorology and Traffic Monitoring Locations within

the Khoraghat Extension ML Block ............................................................................46

Figure 3-7: Topographic Map of Khoraghat Extension ML Block .........................................48

Figure 3-8: Location of Groundwater, Surface Water and Soil Monitoring Locations

within the Khoraghat Extension ML Block .................................................................55

Figure 3-9: Drainage map ........................................................................................................57

Figure 3-10: Percentage Land Cover Distribution of the Block ..............................................61

Figure 3-11: Percentage Land Cover Distribution of the Study area (10 km around the

Block) ...........................................................................................................................61

Figure 3-12: Land Use-Land Cover Map of Khoraghat Extension ML Block ........................62

Figure 3-13: Seismic Zone Map of India .................................................................................67

Figure 3-14: Flood Prone Areas of Khoraghat Extension ML Block ......................................69

Figure 3-15: Ecological Sensitivity Map .................................................................................76


SENES/K-20199/ December 2013 vii ONGC

Figure 3-16: Showing three Herds of Elephant in Golaghat District and the Block ...............77

Figure 3-17: Elephant Corridors of Golaghat District .............................................................78

Figure 4-1: Predicted NOX Concentration Plot (2 X 750 KW DG Set) ...................................97

Figure 4-2: Predicted PM Concentration Plot (2 X 750 KW DG Sets) ...................................98

Figure 4-3: Predicted SO2 Concentration Plot (2 X 750 KW DG Sets) ..................................99

Figure 4-4: Predicted HC Concentration Plot (2 X 750 KW DG Sets) .................................100

Figure 4-5: Noise Attenuation Plot ........................................................................................103

Figure 5-1: Risk Assessment Methodology ...........................................................................118

Figure 5-2: Blow Out Frequencies in Oil & Gas Industry .....................................................126

Figure 5-3: Ignition Probability Vs Release Rate ..................................................................127

Figure 5-4: KHDE Well Site - Pool Fire Risk Contour Map .................................................130

Figure 5-5: KHDF Well Site - Pool Fire Risk Contour Map .................................................131

Figure 5-6: KHDE Well Site – Risk Contour Map for Natural Gas Release ........................134

Figure 5-7: KHDF Well Site – Risk Contour Map for Natural Gas Release .........................135

Figure 5-8: Emergency Classification “Decision Tree” ........................................................140

Figure 5-9: Emergency Response Levels .............................................................................141

List of Photos

Photo 2.1: Agricultural lands within the Block .......................................................................14

Photo 2.2: Degraded forest areas in the Block .........................................................................14

Photo 2.3:Rengma River ..........................................................................................................14

Photo 2.4:Dayang River ...........................................................................................................14

Photo 2.5: Khoraghat GGS 1 ...................................................................................................14

Photo 2.6: Khoraghat GGS 2 ...................................................................................................14

Photo 2.7: Proposed well side KHDE ......................................................................................17

Photo 2.8: Approach Road to KHDE well ...............................................................................17

Photo 2.9: Location of KHDF well- inside Khoraghat GGS1 .................................................18

Photo 2.10: Approach Road to KHDF well .............................................................................18

Photo 3.1: Meteorological Monitoring at Uriamghat ..............................................................40

Photo 3.2: Air Monitoring at Gholapani ..................................................................................43

Photo 3.3: Groundwater sampling at Haldhibari .....................................................................52

Photo 3.4: Groundwater sampling from Chetanapur ...............................................................52

Photo 3.5: Groundwater sampling at Gholapani ......................................................................52

Photo 3.6: Groundwater sampling from Haldhibari Bamchuk Primary School ......................52


SENES/K-20199/ December 2013 viii ONGC

Photo 3.7: Surface water sampling at Dayang River ...............................................................60

Photo 3.8: Surface water sampling at Rengma River ..............................................................60

Photo 3.9: Soil sampling near KHDE well site........................................................................66

Photo 3.10: Soil sampling near KHDF well site ......................................................................66

Photo 3.11: Consultation at Haldhibari Village .......................................................................88

Photo 3.12: Consultation at Gholapani ....................................................................................88


SENES/K-20199/ December 2013 1 ONGC

1 Introduction

1.1 BACKGROUND

The Khoraghat Extension ML Block part of the oil rich Assam-Arakan Basin is located in the

Sarupathar Circle of Golaghat District in Assam. The Block is included under the

hydrocarbon production areas of Oil and Natural Gas Corporation Limited (ONGC). ONGC

already has existing facilities like exploratory wells, production wells, Group Gathering

Stations (GGS) and interconnecting pipelines in the Block.

ONGC is planning to drill two development wells in the Khoraghat Extension ML area I

Golaghat District, Assam. The development and testing of hydrocarbons proposed in

Khoraghat Extension ML Block is included under activities specified in Schedule (Activity

1b) of the new EIA Notification dated 14th

September 2006. It requires Environmental

Clearance (EC) from the Ministry of Environment and Forests (MoEF)..

ONGC has submitted Form-1 of the EIA Notification, along with a draft Terms of Reference

(ToR) for EIA study to MoEF. MoEF has issued approved ToR vide letter J-11011/563/2011-

IA II (I) dated 28th

May, 2012. The approved ToR is attached as Annex 1.1 and is in

compliance as per ToR is presented in Table 1.1.

SENES India has been entrusted by ONGC to undertake an Environmental Impact

Assessment (EIA) for the proposed project. Additionally, as a part of ONGC’s Corporate

HSE Policy, an EIA study will play an important role in formulating appropriate

environmental management response for the proposed development drilling project. In this

perspective SENES has strived to fulfill the project objectives delineated in the section

below.

1.2 OBJECTIVE OF THE STUDY

The objectives of the EIA study are as follows:

To establish the prevailing environmental and socio-economic condition of the

Kasomarigaon Block and its surroundings along with the needs for environmental

approvals to carry out development wells for extraction of hydrocarbons;

To assess environmental and socioeconomic impacts arising out of the proposed

development testing activities;

To recommend appropriate preventive and mitigation measures to eliminate or

minimize pollution, environmental and social disturbances during the life-cycle of the

project, ensuring compliance with environmental laws and regulation as applicable;

To identify and propose alternative action in terms of good practices that may help in

abating environmental or socio-economic impacts due to the project;



1.3 SCOPE OF THE STUDY

The basic scope for this study involves conducting an EIA study to understand the

environmental and social impacts of the Project and recommend suitable

preventive/mitigative actions through the Environmental Management Plan (EMP). The

scope for the study finalized in ToR has been summarized below:

Undertake site visits for collection of primary and secondary information on

environmental and social setting;

Formulate environmental monitoring plan and supervision of the onsite monitoring

program as per plan;

Conduct public consultation;

Assess environmental and social impacts; and

Formulate EMP

1.4 STRUCTURE OF THE EIA REPORT

The EIA report documents results and findings of the EIA study conducted by SENES. The

subsequent sections of the report present description of project activities, environmental and

social baseline scenario, impact and risk assessment that might arise during the lifecycle of

the Project. Consequently, the environmental management plan along with mitigation

measures has been put forth to combat the adverse impacts on the environment. The content

of the report is structured as follows:

Executive Summary

Chapter 1: Introduction

Chapter 2: Description of the Environment

Chapter 3: Description of the Environment

Chapter 4: Impact Assessment

Chapter 5: Quantitative Risk Assessment

Chapter 6: Environmental Management Plan

Chapter 7: EIA Preparers

List of annexure provided below forms a part of the draft EIA report and has been

incorporated at the end of the report as an easy cross-reference.



TABLE 1-1: COMPLIANCE TO MOEF TOR

Sl.

No ToR Points Issued Addressed at EIA

1. Executive summary of a project Will be provided after finalization of the report

2. Project description, project objectives and

project benefits.

Refer Chapter 2 of the EIA Report. Project

objectives and benefits provided at Section 2.2

3. Site details within 1 km of the each proposed

well, any habitation, any other

installation/activity, flora and fauna,

approachability to site, other activities

including agriculture/land, satellite imagery

for 10 km area.

Refer Section 2.6

4. Details of forest land involved in the

proposed project. A copy of forest clearance

letter, if applicable.

The project is located in forest land; Forest

Clearance for KHDF already obtained.

Application of forest clearance of KHDE

submitted to Assam Forest Department (Refer

Section 2.7.1)

5. A copy of forest clearance for the KHDF.

Forest clearance for KHDF already obtained

by ONGC (Refer Section 2.7.1)

6. Status of land acquisition for the location

KHDE

Application of forest clearance of KHDE

submitted to Assam Forest Department (Refer

Section 2.7.1)

7. Permission from the State Forest Department

regarding the impact of the proposed plant on

the surrounding National Park/Wild life

Sanctuary/Reserve Forest/Eco sensitive area,

if any. Approval obtained from the

State/Central Government under Forest

(Conservation Act, 1980 for the forestland

shall be submitted.

The Block is located at a distance more than

20 km from any Wildlife Sanctuary or any

Eco-sensitive Areas. ONGC has already

obtained Forest Clearance from the State

Forest Department for KHDF well and applied

for Forest Clearance for KHDE Well (Refer

Section 2.7.1).

8. Distance from nearby critically/severely

polluted area as per Notification dated 13th

January, 2010, if applicable.

Not Critically Polluted area located within 10

km of the Block (Refer Section 2.5.1)

9. Details of all the environmental clearance

obtained for the block alongwith

pointwise compliance report.

Refer Section 2.1 for EC obtained for the

Block. Point wise EC compliance reports are

submitted twice a year to Assam Pollution

Control Board

10. Details of facilities (GGS, OCS, disposal

of produced water, treatment facility etc)

to be developed/has been developed for

the project.

GGS at Khoraghat already exists. Drill pad for

all the development wells will be prepared.

11. Does proposal involves rehabilitation and

resettlement? If yes, details thereof.

The project will not require resettlement of

any household (Refer Section 2.7.1)

12. Details of project cost. Refer Section 2.11

13. Environmental considerations in the

selection of the drilling locations for which

environmental clearance is being sought.

Refer Section 2.6.2



Sl.


Present any analysis suggested for

minimizing the foot print giving details of

drilling and development options considered.

14. Baseline data collection for air, water and

soil for one season leaving the monsoon

season in an area of 10 km radius with centre

of Oil Field as its centre covering the area of

all proposed drilling wells.

Refer Chapter 3 Baseline Environment

Air Quality: Section 3.1.2

Water Quality: Sections 3.1.6 and 3.1.8

(i) Topography of the project site. Section 3.1.4

(ii) Ambient Air Quality monitoring at 8

locations for PM10, SO2, NOx, VOCs,

Methane and non-methane HC.

Refer Section 3.1.2

(iii) Soil sample analysis (physical and

chemical properties) at the areas located at 5

locations.

Refer Section 3.1.10

(iv) Ground and surface water quality in the

vicinity of the proposed wells site.

Refer Sections 3.1.6 and 3.1.8

(v) Climatology and Meteorology

including wind speed, wind direction,

temperature rainfall relative humidity etc.

Refer Section 3.1.1

(vi) Measurement of Noise levels within 1

km radius of the proposed wells.

Refer Section 3.1.2

(vii) Vegetation and land use; Animal

resources

Refer Section 3.1.9 for Land use. Refer

Section 3.4 for animal resources

15. Incremental GLC as a result of DG set

operation.

Refer Table 4.6 Predicted GLC for air

pollutants

16. Potential environmental impact envisages

during various stages of project activities

such as site activation, development,

operation/ maintenance and

decommissioning.

Refer Chapter 4 Impact Assessment

17. Actual source of water and ‘Permission’ for

the drawl of water from the Competent

Authority. Detailed water balance, waster

water generation and discharge.

Surface water sourced from authorized dealers

will be used to meet the water demand. Tender

notice will be floated before the

commencement of the project.

18. Noise abatement measures and measures to

minimize disturbance due to light and visual

intrusions in case coastally located.

Block is not located in Coastal Area. Noise

abatement measures and measures due to light

and visual intrusion is given in Section 4.2.3

19. Treatment and disposal of waste water. Refer Waste Management Plan at Section

6.1.2

20. Treatment and disposal of solid waste

generation.

Refer Waste Management Plan at Section

6.1.2

21. Disposal of spent oil and loose. The spent oil and loose will be sold to

authorized Vendors. Refer Waste Management



Sl.


Plan at Section 6.1.2

22. Storage of chemicals and diesel at site. Refer Section 2.8.2 Fuel Consumption

23. Commitment for the use of WBM only Water based mud will only be used. But eco-

friendly synthetic mud will also be used if

required. Refer Mud Systems and Cuttings

Section 2.7.2

24. Mud make up and mud and cutting disposal

– all options considered shall be listed with

selective option.

The mud will be made up partly with recycled

water from Rig wash and fresh water and mud

cutting will be temporarily stored at HDPE

lined pits at the site. Later it will be disposed

according to its hazardous and non-hazardous

nature. Refer Waste Management Plan at

Section 6.1.2

25. Hazardous material usage, storage

accounting and disposal.

Refer Waste Management Plan at Section

6.1.2

26. Disposal of packaging waste from site. The packaging waste will be given to the local

vendors. Refer Waste Management Plan at

Section 6.1.2

27. Oil spill emergency plans in respect of

recovery/ reclamation.

Refer Oil spill action plan in Disaster

Management Plan Section 5.4.7

28. H2S emissions control. Earlier exploration shows the absence of H2S

in these Blocks as given in Sec. 2.9.2. Though

a H2S contingency plan exists for ONGC that

will come into action on detecting H2S at any

stage of drilling.

29. Produced oil handling and storage. Stored temporarily in Oil Pits and later

transferred through tankers to the nearest GGS

Refer Well testing Section 2.7.2

30. Details of scheme for oil collection system

alongwith process flow diagram and its

capacity.

Stored temporarily in Oil Pits and later

transferred through tankers to the nearest GGS

as given in Sec.2.7.2

31. Details of control of air, water and noise

pollution in oil collection system.

Not Applicable

32. Disposal of produced/formation water. Refer Waste Management Plan at Section

6.1.2

33. Whether any burn pits being utilized for well

test operations.

Burn pits will not be utilized for the project.

34. Restoration and decommissioning plans

which shall include mud pits and wastage

restoration also and documentation and

monitoring of site recovery.

Refer Section 6.1.3 Site Closure plan

35. Measures to protect ground water and

shallow aquifers from contamination.

Refer Section 4.2.9 Impact on Hydrogeology

and Groundwater Quality

36. Risk assessment and disaster management

plan for independent reviews of well

Refer Chapter 5 Quantitative Risk Assessment



Sl.


designed construction etc. for prevention of

blow out.

37. Environmental management plan. Refer Chapter 6 Environmental Management

Plan and Monitoring Framework

38. Documentary proof of membership of

common disposal facilities, if any.

Not Available

39. Details of environmental and safety related

documentation within the company including

documentation and proposed occupational

health and safety Surveillance Safety

Programme for all personnel at site. This

shall also include monitoring programme for

the environmental.

Regular health check up of ONGC personnel

conducted as per ONGC HSE Policy.

Surveillance safety programs carried at regular

intervals and documented.

40. Total capital and recurring cost for

environmental control measures.

Refer Table 6.1; budget to be included after

discussion with ONGC

41. A copy of Corporate Environment Policy of

the ONGC as per the Ministry’s O.M. No. J-

11013/41/2006-IA.II(I) dated 26th April,

2011 available on the Ministry’s website.

Refer Box 6.1, Chapter 6

42. Any litigation pending against the project

and or any direction/order passed by any

court of law against the project. If so details

thereof.

No litigation is pending against the project.

43. Public hearing issues raised and

commitments made by the project proponent

on the same shall be included separately in

EIA/EMP Report in the form of tabular chart

with financial budget for complying with the

commitments made.

To be provided after Public Hearing

44. A tabular chart with index for point-wise

compliance of above TORs.

Provided in Chapter 1, Table 1.1



2 Project Description

2.1 OVERVIEW

Assam – Arakan Valley situated in the North-eastern part of India is enriched with

hydrocarbon owing to its geological formations. Since the inception of ONGC in 1956, there

has been an extensive proliferation in exploration and development in the Assam – Arakan

basin. The oil and gas fields in the Borholla (in Kasomarigaon), Khoraghat and Nambor in

the Dhansiri valley are situated on the south eastern slope of Brahmaputra arch and lie in a

belt bordering the Naga thrust. ONGC intends to drill new development wells in Khoraghat

Extension ML Block. During the current program ONGC is planning for development

drilling in 2 onshore wells in Khoraghat Extension ML Block.

2.2 OBJECTIVES AND BENEFITS OF PROPOSED DEVELOPMENT DRILLING ACTIVITIES

After the analysis of geological formation of the Oil Fields, ONGC now plans for

development drilling of 3 wells (KHDD, KHDF & KHDE) to determine the prospect of the

potential hydrocarbon sources.

Project Objectives

Objectives of the proposed drilling activities are summarized below:

To drill and evaluate hydrocarbons’ prospects safely

To decide optimum locations of next few wells to be drilled based on geological

models and Geotechnical investigations and Geological mapping.

To construct facilities for hydrocarbon processing and transportation

Project Benefits

The project will benefit in exploration and extraction of hydrocarbon resources which will

support the national energy demand. The project will benefit people living in neighboring

villages in relation to direct & indirect employment associated with various project activities

and will boost the local economy. The proposed project will also result in the improvement of

existing infrastructure.

2.3 BLOCK LOCATION

Khoraghat Extension ML area lies in the Sarupathar Circle of Golaghat District of Assam.

The Block encompasses an area of 83 sq. km. Regional setting of the Oil Field is shown in

Figure 2.1. The geographic location of the Khoraghat Extension ML Block is included

within the Survey of India’s Topo- Sheet No. 83 M/3, 83 M/7 and 83 M/11. The eastern

boundary of the Block is located at immediate proximity (<0.5 km) to Nagaland- Assam

border. The closest town Uriamghat is approximately 12 km by road. The Co-ordinates of the

Khoraghat Extension ML Block are given below in Table 2.1. The Khoraghat Block location

D



map superimposed on toposheet (1:250000) and satellite imagery is shown in Figure 2.2 and

2.3 respectively.

TABLE 2-1: COORDINATES OF THE KHORAGHAT EXTENSION ML BLOCK

Points Latitude (North) Longitude (East)

Deg. Min. Sec. Deg. Min. Sec.

A 26 05 47.57 93 53 12.37

B 26 09 23.07 93 56 06.58

C 26 09 12.44 93 59 55.55

D 26 02 25.57 93 58 17.54

E 26 02 31.29 93 55 37.36

F 26 03 25.27 93 56 03.89

G 26 04 05.34 93 56 52.89

H 26 04 46.23 93 56 07.45

A 26 05 47.57 93 53 12.37

2.4 ACCESSIBILITY

The Block is approximately 310 km away from Guwahati, the state capital and 60 km away

from Golaghat town, the district’s headquarter. The major roadway for accessing the site will

be through NH-36 from Guwahati till Shilanijan from where the rural roads offshoots and

winds through Barpathar, Sarupathar, Chukiapathar, Uriamghat and finally to the site. The

site is approximately 60 km away from Dimapur town in Nagaland. From Dimapur the site

could be accessed by travelling upto Shilanijan via NH-36 and then following the same route

as mentioned above. The two major roads within the Khoraghat Extension ML Block are the

PWD road connecting Uriamghat and Haldhibari Village and the PWD road connecting

Bidyapur via. Lakhinagar.

The closest railway station is in Sarupathar approximately 24km by road, part of North-East

Frontier Railways connects Guwahati with Dibrugarh. It takes 30 min train travel time from

Sarupathar.

The nearest airport is at Dimapur, Nagaland, about 60 km from the Block. Jorhat airport

(also known as Rowriah) is approximately 122 km from the Block. The accessibility of the

Block is shown in Figure 2.4.



FIGURE 2-1: REGIONAL SETTING MAP OF KHORAGHAT EXTENSION ML BLOCK



FIGURE 2-2: KHORAGHAT EXTENSION ML BLOCK ON TOPOSHEET



FIGURE 2-3: KHORAGHAT EXTENSION ML BLOCK ON SATELLITE IMAGERY



FIGURE 2-4: KHORAGHAT EXTENSION ML BLOCK ACCESSIBILITY MAP



2.5 KHORAGHAT EXTENSION ML BLOCK

2.5.1 Environmental Settings of the Block

The Khoraghat Extension ML Block is located in Golaghat District of Assam and spreads

over an area of about 83 sq. km. The Field is located in areas of Sarupathar Revenue Circle of

Golaghat district. The key physical features (Refer Figure 2.5) of Khoraghat Extension ML

Block Field have been described below:

The Block is polygonal in shape having approximate longitudinal dimensions of 9.79

and 12.85 km at its widest and lengthiest point.

The Block lies in the watershed of Dhansiri River. However, the proposed wells

within the Block lie within the micro-watershed of Dayang and Rengma rivers.

Dayang River, a tributary of Dhansiri River, runs alongside the hilly area bordering

Nagaland on the eastern margin. Rengma River flowing through the central part of the

Project area is a tributary of Dayang River is on the western margin. The land is criss-

crossed by meandering courses of Dayang and Rengma rivers longitudinally on both

of its sides in the South-North Direction. The confluence of Dayang and Rengma

rivers lies at the north of the Block. The remnants of dried ox-bow lakes are dotted on

the landscape.

The Naga hills are present on the eastern and southern margin of the Block. The

rivulets flowing down the hills feed water to the above-mentioned rivers throughout

the year. They also cause flash floods in these areas.

The land within the Block is under Rengma Reserve Forest but devoid of any

vegetation cover. The entire forest area had been encroached and settlements,

agricultural land had been developed by deforestation of Rengma Reserved Forest.

The current land cover within the Block included primarily of agricultural lands with

settlements and homestead plantation. Uriamghat is the major town within the Block.

There are about 38 nos of settlements within the Block.

The Block is included under the existing oil and gas producing area of ONGC.

Production well sites, two Gas Compressor Stations (GGS) and interconnecting

pipelines are located within the Block

No critically or severely polluted area is located within 10 km of the proposed Block.

2.5.2 Salient Features

The water consumption, generation of drill cuttings and drilling fluid is determined by depth

and type of well as presented in Table 2.2.



Table 2-2: SALIENT FEATURES OF A TYPICAL EXPLORATORY WELL

Photo 2.1: Agricultural lands within the Block Photo 2.2: Degraded forest areas in the Block

Photo 2.3:Rengma River Photo 2.4:Dayang River

Photo 2.5: Khoraghat GGS 1 Photo 2.6: Khoraghat GGS 2

Type of Well Depth of Well Water

Consumption

Drill

Cutting

Drilling Fluid

Development 2500 m 900-1000m3 225m

3 1250m

3



FIGURE 2-5: ENVIRONMENTAL SETTINGS OF KHORAGHAT EXTENSION ML BLOCK



2.5.3 Existing Activity in Oil Field

The Khoraghat Extension ML Block is included under producing field of ONGC which is

being operated since 1989. The main activities conducted by ONGC at the Block are

Development and Production well drilling

Production of hydrocarbons from producing wells

Transportation of oil and gas to respective Group Gathering Stations (GGS) via.

interconnecting pipelines

2.5.4 Environmental Compliance

Khoraghat Extension ML Block is an operational Block of ONGC. The Block was granted

Environmental Clearance (EC) from MoEF vide letter nos. F. No. J-11011/625/2007- IA II

(I) dated October 22, 2007 (Annex 2.1).

2.6 WELL LOCATIONS AND ENVIRONMENTAL SETTINGS

2.6.1 Location of Wells

The proposed well sites were selected based on environmental considerations viz. location of

sensitive ecological habitats, settlements, schools/ hospitals, water bodies etc. Care had been

taken to located wells distantly from these receptors. Agricultural lands were selected for

current well drilling program.

Total 2 development wells are proposed in the Khoraghat Extension ML Block during the

plan period. Tentative well coordinates are provided in Table 2.3and the locations of the

wells at Khoraghat Extension ML Block are shown in Figure 2.6.

TABLE 2-3: COORDINATES OF TENTATIVE WELL LOCATIONS

Location Latitude (Northing) Longitude (Easting)

KHDE 26⁰05/07.106

// 93⁰57

/10.66

//

KHDF 26⁰04/45.708

// 93⁰56

/55.91

//

KHDD 26°03' 50.75" N 93°56'41.79" E

2.6.2 Environmental Settings

Environmental setting around one km radius area (referred as study area) of each well site

was carried out during field survey and the same has been checked with satellite imagery.

Location of wells were finalized keeping in mind the following considerations sensitive

ecological habitats, settlements, schools, hospitals etc. Well wise environmental settings are

described below.



KHDE

The proposed well site KHDE is located at the agricultural land of Haldhibari village. This

well site is close to (approximately 150-200 m) the existing temporarily abandoned well site

namely CLAA18 of ONGC, located at the West. The nearest village of Haldhibari (around

500-700m) lies in a linear alignment along North-East to South-East. Settlements of

Haldhibari and Gholapani villages are located at the west of the well site. The proposed well

site could be accessed by NH-39 via. Sarupathar, Barapathar and Uriamghat towns. From

Uriamghat an 11 km stretch of dilapidated PWD road connects the well site. Settlements of

Haldhibari village are located close to the approach road. Dayang River flows on the eastern

part of the site lies within 2 km from the site.

Photo 2.7: Proposed well side KHDE Photo 2.8: Approach Road to KHDE well



KHDF

The proposed well site lies at the existing facility GGS-1 of ONGC. KHDF well site is

located around 0.9 km north east of KHDE well site and could be accessed by the same

approach road as that of KHDE upto Haldhibari- Tiniali. A rural road (pitch and stone mix)

connects the proposed well site with Haldhibari Tiniali. This facility lies very close to (100m)

Chetanapur on west-west-south and 400 m from village Haldhibari stretching from South-

East to South. The other settlement within 1 km of the site on the East is Bidyapur.

Photo 2.9: Location of KHDF well- inside

Khoraghat GGS1

Photo 2.10: Approach Road to KHDF well



KHDD

The proposed well site lies within agricultural field of Gholapani village. The well site is

located about 100 m from the village road connecting Gholapani with Sankarpur village.

There are no perennial waterbodies within 1km of the proposed well site.



FIGURE 2-6: LOCATION OF PROPOSED WELLS



2.7 PROJECT ACTIVITIES AND SCHEDULE

The lifecycle of project activities for the exploration project has been divided into distinct

steps and each is described in detail in the subsequent sections and will take approximately

three-four months to complete drilling and testing activity at each well site.

The project lifecycle has been classified into three phases:

Pre-drilling activity

Site selection

Land acquisition

Site access road and drill site construction

Pre-drilling activities, mobilization and Rigging up

Initial well construction

Drilling activity

Drilling of wells

Well testing

Well decommissioning

Well abandonment

Site closure and decommissioning

Site Restoration

2.7.1 Pre-drilling Activity

The pre-drilling phase will involve the following activities:

Site Selection

The major consideration for the site selection is geological formation. All locations were

selected by ONGC’s drilling department based on geological data available. A preliminary

site survey was already undertaken by the ONGC drilling team. Suitable drilling locations

were selected based on the physical (terrain and access) and technical suitability. Based on

above geological consideration, the following environmental considerations were adopted

during selection of drill site

Away from organized human habitats.

Easy access to area of interest



Land Acquisition

Land for the KHDF drill site is already in possession with ONGC and is located within the

premises of Khoraghat GGS-1. Land acquisition for KHDD and KHDE is under progress.

Forest Land and Forest Clearance

Both the proposed well sites are included within the Rengma Reserve Forest, as per Forest

(Conservation) Act, 1980. ONGC has already taken Forest Clearance for KHDF well site.

Application for Forest Clearance for KHDD and KHDE has been submitted to DFO,

Golaghat and is currently being processed.

As described in the earlier section entire forest is deforested and presently used for

agriculture and human settlement. The people residing at the Block are a mixture of tribal and

non-tribal and their livelihood is dependent on these diverted forest land. Agriculture is

extensively practiced by the inhabitants over several decades in these areas. Therefore as per

provision of The Scheduled Tribes and other Traditional Dwellers (Recognition of Forest

Rights) Act 2006, ONGC has taken the proposed land (long term lease) from the villagers

who are presently cultivating the land. The villagers will be adequately compensated for the

above-mentioned period of activity. Crop compensation would also be provided to the land

owners. The estimated land required for KHDD and KHDE is approximately 3.38 ha.

Though located within reserved forest areas, absence of vegetation cover at the well sites will

not render adverse impacts on flora and fauna of the area. The details of the ecological impact

assessment are provided at Chapter 4.

Human Settlement and R&R Issue

The existing land use map and ground verification clearly shows that only forest land will be

utilized for construction of developmental drilling activities. No human settlement will be

affected by proposed activity and no human settlement area also would be required to

rehabilitate. In case of Khoraghat Block R&R issues is not applicable to this project.

Access Road and Site Construction

Construction of Access Road

The well site KHDF is located at the existing site of GGS-1 which already has a paved access

road. The road will be strengthened for transporting the rig and ancillary equipments. A 50 m

approach road will be constructed for KHDE and the existing road towards CLAA18 will be

strengthened. Approximately, 0.02 ha [(50 m) length x 4.0m width] land will be required for

construction new approach road for KHDD and KHDE. These lands are forest land but

presently deforested and used for agriculture. As the proposed land is a forest land, ONGC

has to take forest clearance as per Forest (Conservation) Act, 1980 and villagers are

dependent on these forest land (agriculture), ONGC has to be adequately compensated for

taking long tern lease and crop compensation. The preliminary alignment of the proposed

new road reveals that, there is no tree or settlement. Therefore construction of new approach

road will not required any tree felling or resettlement of any household.



Culverts and drainage channel will be strengthened during site preparation as required. The

approach road will be constructed by a contractors appointed by ONGC.

Construction of Drill Site

As described in the earlier section KHDF will be drilled within the existing Khoraghat GGS-

1. As, KHDF drill site was already constructed. Therefore, no site construction will be

required for above mentioned well. However, KHDD and KHDE are new drill sites; site

construction will be required for the well. The proposed well site does not have any tree and

any other structure. Therefore, tree felling and any demolition will not be required. The

following sub-activity will be carried out for construction of new drill sites:

Fencing: The proposed well site & campsite will be duly fenced to a height of about 2 m

using chain link and barbed wires to restrict unlawful entry into the site.

Top Soil Scraping: The depth of the top soil of the entire drill site will be gauged, scraped and

stored in designated top soil storage site for future use (site reclamation and rehabilitation).

The preservation of top soil on site is described in detail at Chapter 6.

Construction of Drill Platform Once the top soil removal process is completed, the entire drill

site will be elevated and leveled and compacted. The drill site may require filling of earth to

elevate the drilling platform based on local topography and High Flood Level (HFL).

Quantity of fill material required for each drill sites depends upon the site elevation and HFL.

Fill material will be met from excavated material for pit required for drill site and balance

amount will be sourced from authorized quarry area. Pits will be required for storage of mud,

drill cutting, waste water, formation water, etc. These are as follows:

Construction of Drill Pad: A flat rectangular/square drilling site (pad) of 15X15 m

(approximate) at site to facilitate drilling and testing of hydrocarbons will be required.

Reinforced Cement Concrete (RCC) will be used for the construction of foundation system.

For the construction of a drill site, a total of about 100 tonnes of cement, 100 tonnes of sand,

and 100 tonnes of stones will be procured from local dealers.

Excavation of Pits:

A backhoe will be used for all excavation and cutting activities (for construction of pits) on

site. The following pits would be excavated within the well site

Construction of cellar pit 3m X 3m X 3 m for installation of well head and BOP

Construction of 2 HDPE lined pit of dimensions 30’X 33’X 5’ at well site for

temporary storage and disposal of drill cutting

Construction of 2 HDPE lined pit of dimensions, 38’X 33’X 5’ and 23’X 20’X 5’for

temporary storage and disposal of drilling mud.

Construction of 1 Oil pit of dimension of 3’X 3’X 4’



Soak pits will be constructed to dispose the domestic wastewater and sewage at the

drill site.

Construction of Bunds & Strom Water Drains: The soil excavated from the pits will be used

to build a raised bund/embankment bordering the periphery of the drill site. A storm water

drain is constructed before the bund. Oil-water separator and silt-trap will be constructed at

one end of the storm water drain.

30-40 truckloads of material are expected to be sourced to the well site during site

construction. The transport of rig including ancillary equipments and camp facilities to the

site are expected to comprise around 50-60 trailer loads. Though the rig and related

equipments will be directly brought to site, spares, chemicals and other materials will be

received at the warehouse located at Jorhat. Materials will be intermittently supplied from

warehouse to the drilling site, during operations; a provision will be kept for temporary

storage of materials at the drilling site itself.

Rig Mobilization and Rigging up

A rig building process will follow the site preparation activities. This process involves

transport of rig including auxiliary equipments and camp facilities, assembling of various rig

parts and equipment to drill a well. The rig including auxiliary equipments and camp

facilities will comprise of around 50-60 trailer loads. Once the drilling rig is assembled,

thorough rig inspection will be carried out to check equipment working capability and quality

standards. The rig will have various allied equipments like mud tanks, mud pumps,

compressors, fuel tank, DG sets etc.

Well spudding is the start of drilling activity. Top-hole section will be drilled to a desired

depth based on well design. After drilling top-hole section, it will be cased with a pipe called

“Casing”. Casing provides support to hole wall and secures hole section. Other than that, it

isolates problematic hole sections such as loss zones, shale sections, over pressurized

formations etc. After running casing, space between hole wall and “Casing” will be

cemented. This process of drilling and casing the hole section continues until the final well

depth (target) is achieved.

Lengths and diameters of each section of the well are determined prior to drilling and are

dependent on the geological conditions through which the well is to be drilled. Once each

section of the well is completed, the drill string is lifted and protective steel pipe or casing

lowered into the well and cemented into place.

2.7.2 Drilling Activity

To support the drilling operation, the following systems and services will be included at the

rig package:

Environmental Protection – Blow Out Prevention (BOP) system, wastewater

treatment unit, cuttings handling equipment.



Drilling of Well

The exploitation of hydrocarbons requires the construction of a conduit between the surface

and the reservoir. This is achieved by the drilling process. The exploration well will be

drilled using a standard land rig or a “Mobile Land Rig” with standard water based drilling

fluid treatment system. This rig will be suitable for drilling up to the desired depth of 2500-

3000 metres as planned for the project. The typical configuration of a Drilling Rig is shown

in the Figure 2.7. Drilling is a temporary activity which will continue for about 45-60 days

for each well in the block. The rigs are self-contained for all routine jobs. Once the drilling

operations are completed, and if sufficient indications of hydrocarbons are noticed while

drilling, the well is tested by perforation in the production casing. This normally takes 2-3

days. If the well is found to be a successful hydrocarbon bearing structure, it is sealed off for

future development, if any. Additionally, there will be other ancillary facilities like Drilling

mud system, ETP, Cuttings disposal, Drill Cementing equipment etc. and utilities to supply

Power (DG sets), water, fuel (HSD) to the drilling process and will be set up as a part of the

project.

FIGURE 2-7: TYPICAL DRILLING RIG CONFIGURATION



Mud System and Cuttings

During drilling operations a fluid known as drilling fluid (or ‘mud’) is pumped through the

drill string down to the drilling bit and returns between the drill pipe –casing annulus up to

surface back into the circulation system after separation of drill cuttings /solids through solids

control equipment. Drilling fluid is essential to the operation and helps in controlling

downhole pressure, lift soil/rock cuttings to the mud pit, prevent cuttings from settling in the

drill pipe, lubricate, cool and clean the drill bit amongst other functions.

An uniform water-based mud system will be used in all the development drilling activities.

Unlike an oil-based mud system, usage of water-based mud will not pose higher risk of

contamination to subsurface formations, but disposal of the fluid and cuttings will be less

problematic. Though for formations where water based mud will not be suitable, eco-friendly

synthetic based mud will be used.

The ingredient of water based drilling fluid is given in Annex 2.2. The special additives and

their functions in water-based drilling fluids is presented in Annex 2.3.

Mud used during the operation will flush out formation cuttings from the well hole. These

cuttings will be separated from the drilling mud by thoroughly washing. Cuttings will then be

stored in the HDPE lined pits (of approximately 2 X 140 m3 capacity) and after completion of

the drilling activities, cuttings will be tested for hazardous nature and based on nature of the

drill cuttings, final disposal pathway will be finalized by ONGC as per Sl No 72 C of GSR

546 (E) dated 30th

August, 2005. The total amount of cuttings produced during the entire

drilling period is projected to be about 212-225 m3.

Once the cuttings have been separated, the drilling fluid will be reused or processed after

further treatment in a Chemically Enhanced Dewatering (CED) system designed to remove

suspended solids that are too fine for mechanical separation in solids control package

producing inlet particles called ‘flocs’. The flocs will be removed in the decanting centrifuges

and the resultant sludge disposed off in High Density Polyethylene (HDPE) lined pit (of

approximately 2 X 140 m3 area). The cleaned waste water will also be stored in HDPE lined

pits and disposed off, after testing and any necessary treatment, to meet the regulatory

requirements.

The whole process by which the drilling fluid will be reused during the drilling operation and

is commonly known as a “closed loop system”. This system is ideal for drilling operations in

sensitive environments as it cuts down immensely on the total water consumption for the

formulation of drilling mud and also saves on the consumption of chemicals. Figure 2.8

shows the drilling fluid circulation system which is designed to enable the drilling fluid to be

recycled and maintained in good condition throughout the operation. Figure 2.9 shows the

schematic layout of the drilling waste management.

Various components of the drilling mud will be selected carefully to be able to provide

desired properties to the mud. Mud chemicals will be added to the uniform mud system to



adjust the mud properties and ensure fluid loss control/circulation, lubricity, shale inhibition,

pH control and pressure control in the well during drilling.

Chemicals required for the preparation of drilling fluid will be centrally stored in Jorhat.

Additionally, some chemicals will also be stored in the drill site. The storage area will be

paved and bunded and will be provided with a shed.

FIGURE 2-8: TYPICAL DRILLING FLUID CIRCULATION SYSTEM



FIGURE 2-9: DRILLING WASTE MANAGEMENT

Cementing Programme

Cementing is a necessary aspect of drilling oil and gas wells. Cement is used to

Secure/support casing strings

Isolate zones for production purposes

Solve various hole problems

Cementing generally utilizes Portland Cement (API Class G Oil Well Cement) with various

additives in small quantities as accelerators/retarders, density adjusters, dispersants, fluid loss

additives, anti gas migration additives, etc.

Well Testing

Between the drilling operations for different zones, logging operations are undertaken to

provide information on the potential type and quantities of hydrocarbons present in the target

formations. Technicians employed by ONGC/ specialist Logging Service Company will be

entrusted with the job of undertaking well logging. Logging instruments (sensors) will be

attached to the bottom of a wire line and lowered to the bottom of the well. They are then

slowly brought back, the devices reading different data as they pass each formation and

recording it on graphs, which can be interpreted by the geologist, geophysicist and drilling

engineer. There are no emissions to the environment associated with wire line logging



operations. The radioactive source required for well logging operations will be kept in

specially designed container. Oil produced during testing activities or during development

phases will be stored at the oil pit and will be transferred to the nearest GGS by Oil tankers.

2.7.3 Well Decommissioning

Well Abandonment

After the development activities the well will be sealed with a series of cement plugs, all the

wellhead equipment will be removed leaving the surface clear of any debris and site will be

restored.

Site Closure and Decommissioning

After completion of the drilling activity, partial de-mobilisation of the drilling rig and

associated infrastructure will be initiated. As discussed earlier, well testing may be carried

out immediately after the drilling is completed or about 3 months depending on initial

evaluation timing. The complete de-mobilisation of the facilities at site will happen after

well-testing has been completed. This will involve the dismantling of the rig, all associated

equipments and the residential camp, and transporting it out of the project area. It is expected

that demobilization phase will last about 10 days and will involve the trucking away of

materials, equipments and other materials from site to bring it back to original condition. It is

estimated that about 50 truckloads will be transported out of site during this period.

Subsequently, following steps will be typically involved to restore and rehabilitate the area:

The wellhead and all casing string will be cut off to a minimum depth of 3 m (10

ft) below ground level.

All concrete structures will be broken up, and the debris disposed off as per the

regulatory requirements.

Drill cuttings and drill mud will be treated as per G.S.R 546 (E) dated 30th

August

2005 to render them harmless.

Drilling wastewater including drill cuttings wash water shall be collected in

HDPE lined disposal pit, evaporated and treated and shall comply with the S No.

72, Schedule I-Standards for Emission or Discharge of Environmental Pollutants

from various industries.

All fencing and access gates will be removed.

All pits whose contents will show regulatory compliance for on-site disposal, at

the time of site closure, will be backfilled and closed out as per the legal

requirements.

Restoration of unusable portion of the access track, removal of pilings and

Landscaping.



Site Restoration

All abandoned drill sites will be restored back to its near original condition. After

decommissioning of site, it will be de-compacted and stored top soil will be overlaying on the

de-compacted site with certain moisture conservation measures and seeding of leguminous

plant for restoration soil nutrient level naturally.

2.8 UTILITIES & RESOURCE REQUIREMENTS

2.8.1 Power Supply

The drilling process requires movement of drill bit through the draw works which require

power. The power requirement of the drilling rig will be met by using the six AC-SCR Diesel

Generator Sets with a diesel consumption of about 6 KLD. The exhaust stacks of the DG sets

are likely to vent the emissions. Power requirement for the drill sites is provided below;

TABLE 2-4: POWER REQUIREMENT BREAK UPS

Activity Power requirement No. of DG set

During site construction AC-SCR DG set of 750 KW 1

During drilling operation AC-SCR DG set of 750 KW 2 operable 1 standby

Lighting and other power

requirement AC-SCR DG set of 750 KW 1

The power requirements at the site preparation and construction phase for the drill site will be

met by 750 KW DG Sets. Although drilling operations will be continuous, power

requirement will vary depending on activities being carried out. It is anticipated that four DG

sets with a power rating of 750 KW each will be required for drilling purposes of which one

will be kept standby. Lighting and other power requirements at drill sites will be met through

one 750 KW DG sets.

2.8.2 Fuel Consumption

Fuel consumed during the drilling phase will mainly be diesel used by rig used for

development drilling, various equipments and vehicles operating to transport goods and

supplies to site. It is estimated that about 1-1.5 KLD diesel per day will be required to power

the off-road construction equipment and vehicles during site preparation phase.

During the drilling phase, consumption about 6 KLD of High Speed Diesel will be required.

Fuel will be supplied onsite by local supplier through mobile tankers. Out of this, a major

part comprising about 85% will be consumed by the rig (also include the DG sets) and about

15% will be required for the campsite. In case the storage exceeds the threshold limits

specified in the Petroleum Rules, 2002, ONGC will comply with the relevant provision of

such rules.



2.8.3 Water Consumption and Supply

The water requirement in a drilling rig is mainly meant for preparation of drilling mud apart

from washings and domestic use. While the former consumes the majority of water

requirement, the water requirement for domestic and wash use is very less. The daily water

consumption will be 20 m3/day of which 10 m

3/d will be used for rig washing, 10 m

3/d will

be used for mud preparation.

Water will be sourced from contractors after validating their proper withdrawal permission

from concerned authorities. The water requirement per well is shown in Table 2.4.

TABLE 2-5: WATER REQUIREMENT PER WELL

A provision for storage of about 140 KLD of water (5 days water requirement during peak

period) will be made on site. Potable water requirement at site will be met through filtered

bore well water and some packaged drinking water.

Total water requirement for the drill site preparation and construction phase of the project is

estimated to be about 10 KL. With average time requirement for site preparation being

approximately 20 days, about 0.5 KLD of water will be consumed daily, on an average. In

addition, a water storage pit of around 1000 KL is proposed to store water for fire water

supply the likely source being surface water.

The water balance diagram is provided at Figure 2.10.

Description Quantity

Total Water Requirement for Drilling (KL) 900-1200

No. of Days on well 45-60

Average drilling water consumption per day (KLD) 20



FIGURE 2-10: WATER BALANCE DIAGRAM

2.8.4 Effluent Treatment

The drilling waste water around 1000 -1200 m3 will be generated during the entire drilling

period from rig wash and dewatering of spent drilling mud. A mobile ETP of a capacity of

125m3/day will be installed to treat the waste water.

2.8.5 Manpower / Employment

The drilling rig will be operated by approx 25-30 persons on the rig at anytime. The

manpower will operate in two shifts with continuous operations on the rig. This will include

technical experts (including expats), who will be responsible for various drilling related

activities and some local workmen who will be hired from nearby villages for the entire

duration of the project. Technical staff will be housed in the Drilling Camp Site which will be

adequately supported by facilities like kitchen, wash rooms, laundry, etc.

10

m3/d

9

m3/d

10 m

3/d

Treated at ETP to conform with CPCB

discharge standards

Rig wash Mud

Preparation

HDPE lined

Pit

Water sourced from surface water source

(20m3/day)

Reuse and

Recycle



2.9 POLLUTION SOURCES AND CHARACTERIZATION

2.9.1 Noise and Vibrations

Noise will be emitted from development drill site during site preparation, drilling and

decommissioning phases. The major noise generating operations from the proposed activity

during drilling, testing are operation of rotary drilling equipment as part of rig, diesel engines

for power generation, mud pumps and operation of vehicles. Noise during the site preparatory

phase will primarily be contributed by heavy construction machinery operating on site and

vehicular sources. Average noise emission ranges for different types of construction

machinery are shown in the Table 2.5.

As drilling activity is continuous, part of the noise associated with functioning of the rig and

ancillaries will be generated throughout day and night. Noise generated from rig and ancillary

equipments is shown in Table 2.6.

TABLE 2-6: TYPICAL NOISE EMISSIONS FROM CONSTRUCTION MACHINERY

Equipment Sound Level At Operator (in decibels)

Average Range

A. Earth Moving Equipment

Front End Loader 88.0 85-91

Back Hoe 86.5 79-89

Bull Dozer 96.0 89-103

Roller 90.0 79-93

Truck 96.0 89-103

B. Material Handling Equipment

Concrete Mixer <85.0 -

Crane/Hydra <85.0 -

Derrick 100 97-102

Source: British Columbia, “Construction Noise,” Workers Compensation Board of BC

TABLE 2-7: DRILLING RIG & EQUIPMENT NOISE LEVELS1

Equipment Equivalent noise levels in dB(A)

Average Range

Drilling Rig 96.9 88.0-103.0

Mud Pumps 76.9 73.3 -80.5

Diesel Generators 72.7 71.8-73.7

Shale Shakers 76.6 -

1 “Noise Report on Drilling Operation” – British Drilling & Freezing Ltd – Prepared by K A Worthington; AEC

Report: P852-2; 17th

October 2002;



2.9.2 Air Emissions

Air emissions from point sources expected from the proposed development drilling will be

mainly from combustion of diesel in the diesel engines and power generators which will be

operated to meet power requirement of the drilling rig and the campsite. The principal

pollutants will comprise of Particulate Matter (SPM), Sulphur and Nitrogen dioxides (SO2

and NO2) and other hydrocarbons (HC). The quantity of diesel consumed during drilling will

be in order of 6 KL /day/drilling site.

Additionally, the flaring and burning of oil during the testing of the well will also lead to the

release of some pollutants including un-burnt hydrocarbons to the atmosphere. Some fugitive

emissions of dust and air pollutants from vehicular exhaust will also happen during the

project lifecycle, mostly during the construction and decommissioning activities.

Additionally, there will be re-entrainment of dust from the approach road leading to the site

mainly during the dry season.

Analysis of natural gas generated from the earlier well sites revealed the absence of hydrogen

sulfide from these formations of Assam-Arakan Basin. If at all hydrogen sulfide is emitted,

ONGC will apply industry best practices to minimize the effect of the same to ambient

environment.

2.9.3 Liquid Wastes

During the drilling operations, drilling wastewater generated (approximately 9 m3 per day) as

a result of rig wash and dewatering of spent mud, effluents from washing of drill cuttings,

floor washings, pump, seal leakages, spillages will comprise of chemical ingredients of

drilling fluid thereby rendering effluent to be polluted. The characteristics of drilling and

wash wastewater will be primarily dependent on type and composition of drilling fluid used

for drilling. As ONGC is proposing the use of water-based drilling mud, the potential for

contamination of such waste water is significantly lower. The drilling wastewater will contain

spent drilling fluid generated as a result of washings. The rig wash water and drilling

wastewater generated is proposed to be collected in a wastewater pit (of capacity 800 m3)

constructed at the drilling site. Domestic waste water generated (about 8 KLD for the drilling

camp) will be treated through a soak pit/septic tank arrangement.

The quantities of the liquid wastes, their characteristics and anticipated disposal methods are

given in Table 2.7.

TABLE 2-8: LIQUID WASTES GENERATED DURING DRILLING AND THEIR DISPOSAL

Waste Type Quantity Disposal

Drilling and wash

Wastewater 10 m

3 per day

The water will be adequately treated in an ETP to

ensure conformance to the CPCB onshore oil and

gas extraction industry effluent standards

Domestic Wastewater 2.4 m

3 per day from

drilling site Septic tank followed by soak pit



2.9.4 Solid and Hazardous Waste Streams

The different solid and hazardous waste streams generated during drilling and their disposal

methodology has been presented in Table 2.8.

TABLE 2-9: WASTE STREAMS GENERATED DURING DRILLING AND THEIR DISPOSAL

Waste Type Quantity Characteristics Disposal

Kitchen Waste 10 – 20 kg

per day

Organic waste

(Non HW)

Will be stored in compost pits on

daily basis.

Drill Cuttings 212-225

m3/ well

Mainly Inert material

Consisting of shales,

sands and clay; about

1% of drilling mud.

(Non HW)

Drill cuttings will be disposed off in

a well designed pit lined with

impervious liner located on site as

per S No. 72 C.1.a Schedule I

Standards for Emission or Discharge

of Environmental Pollutants from Oil

Drilling and Gas Extraction Industry

of CPCB as modified in 2005.

Waste Drilling

Mud

(Fluid)

4 m3

Barite, Bentonite and

Traces of

Heavy metals (HW)

The mud will be tested for hazardous

contaminants and will be disposed as

per S No. 72 C.1.a Schedule I

Standards for Emission or Discharge

of Environmental Pollutants from Oil

Drilling and Gas Extraction Industry

of CPCB as modified in 2005

Acid – Lead

Batteries

2 – 3

Batteries

per

drilling of

well

Lead – Acid (HW)

Will be recycled through the vendors

supplying acid – lead batteries as

required under the Batteries

(Management & Handling) Rules,

2001.

Oily waste-

used oil &

spent Oil and

loose

0.3 m3

5-10 Kg Used & Waste oil

Will be collected in metal drums kept

in secured dyked area & Disposed as

per Used oil rules in approved used

oil recycling facility

Recyclables

viz. paper,

plastic,

packaging

wastes

Depending

on usage

- Proper segregation and storage of

recyclable waste in designated bins

onsite. Recyclables will be

periodically sold to local waste

recyclers.

2.10 DRILLING HAZARDS

Loss of well control / blow-out, fire, explosion and oil spills are the major potential hazards

associated with drilling for oil and gas. Effective response plans to foreseeable emergencies

will be developed by ONGC and communicated to the project teams. A risk assessment to be

carried out as part of this EIA will also contribute towards identification of hazards, risks and

formulating management plans for emergency response, blowout, oil spills.



2.11 PROJECT COST

Based on ONGCs previous experience of drilling in the area, cost for drilling for of 3 wells

(including well site construction and site decommissioning) will be approximately INR 75

crores. The cost of drilling will depend on the depth of the well to be drilled.

2.12 HSE POLICY

ONGC is committed to protecting environment, health and safety of the people who may be

affected, directly or indirectly by its operations. The Drilling Management System (DMS)

framework lays down the corporate Health, Safety and Environment Policy for the entire

organization and the range of operations it undertakes as a part of oil and gas exploration.

The overall corporate health environmental safety policy of ONGC may be supplemented by

a local policy document whenever so required. It is understood that ONGC will try to

formulate a local site level policy taking from the parent corporate policy of ONGC to

adequately address the environmental impacts of the proposed drilling projects in Khoraghat

Extension ML Block Field through the DMS.



3 Description of the Environment

This chapter describes the existing environmental settings in the Khoraghat Extension ML

Block and its immediate surroundings. This includes the physical environment comprising

air, water and land components, the biological environment, and socio-economic

environment. Attributes of the physical environment like air, water, soil, and noise quality in

the surrounding area were assessed primarily through monitoring and analysis of samples

collected from field. Air, traffic and noise monitoring was carried out by Cleenviron Private

Limited (CPL), Rourkela (a NABL certified laboratory); water and soil monitoring were

conducted by Mitra S. K Pvt. Ltd (also a NABL certified laboratory). All monitoring at field

were undertaken under the guidance and supervision of SENES personnel during the pre-

monsoon season of April 2013-June 2013. Information about geology, hydrology, prevailing

natural hazards like floods, earthquakes etc. have been collected from literature reviews and

authenticated information made available by government departments. Surveys were carried

out to understand and record the biological environment prevailing in the area and the same

was verified against published information and literature. The socioeconomic environment

has been studied through consultations with various stakeholders in the villages within the

Khoraghat Extension ML Block. Additionally, socioeconomic data have been obtained from

the Census of India reports.

3.1 PHYSICAL ENVIRONMENT

3.1.1 Climate & Meteorology

Climate and meteorology of a place can play an important role in the implementation of any

developmental project. Meteorology (weather and climate) plays a key role in understanding

local air quality as there is an essential relationship between meteorology and atmospheric

dispersion involving the wind speed/direction, stability class and other factors. The block

falls under the humid sub tropical climate zone.

Based on primary meteorological monitoring conducted during April-June 2013 at

Uriamghat within the Block the temperature profile, rainfall pattern relative humidity, wind

speed and wind direction of the region have been discussed below.

Interpretation of Primary Baseline Data

Temperature

Micrometeorological data obtained for temperature as part of baseline monitoring undertaken

for the proposed project during pre-monsoon season revealed the daily maximum and

minimum temperature at 21.82°C and 40.27 °C respectively. The micrometeorological values

recorded for temperature have been provided in Annex 3.1.



Relative Humidity

Daily maximum and minimum Relative Humidity (RH) was recorded at 31.95% and 98.81%

respectively during the primary monitoring study. The hourly variation of average relative

humidity has been listed in Annex 3.1.

Rainfall

About 112.8 mm of total rainfall was recorded during primary monitoring period. Twenty

two rainy days were recorded with 38.4 mm being the maximum rainfall value recorded. The

micrometeorological values recorded for rainfall have been provided in Annex 3.1 for

reference.

Wind Speed and Wind Direction

The wind speed and wind direction of an area influences the dispersal of pollutants from a

point and non point sources. As the proposed drilling and testing activities involve the

operation of both point (DG sets) and non point pollutant emissions sources, analysis of wind

speed and direction data is considered important for predicting the air quality impacts based

on pollutant dispersion.

Hourly micro-meteorological data collected during primary monitoring has been analyzed to

generate the post monsoon and winter season wind rose. The predominant wind direction

was observed to be from South East for the study period. The average wind speed for the

months was 0.80 m/s. The wind speed was observed primarily in the range 0.5 – 2.1 m/s for

the monitoring period. The calm frequency was recorded as 40.8%. The wind rose diagram

generated for the primary monitoring study period and wind class frequency distribution have

been presented in Figures 3.1 and 3.2 and wind speed & wind direction data have been

provided as Annex 3.1 for reference.



FIGURE 3-1: WIND ROSE DIAGRAM FOR PRE-MONSOON SEASON

FIGURE 3-2: WIND CLASS FREQUENCY DISTRIBUTION



3.1.2 Ambient Air Quality

Primary monitoring of the existing air environment was undertaken in the Field to establish

existing ambient air quality within the proposed Field. Location of the proposed wells and the

predominant wind direction is important in selection of the ambient air quality sampling

stations as any gaseous and particulate emission from the project activities will disperse

based on the predominant wind directions and affect to the receptors located at that end. Thus

the analyzed values for the pre project environment can be compared during and after the

project activities. The major industrial sources of air emission at the Field are from

hydrocarbon exploration and production of ONGC.

Ambient air quality monitoring was conducted at 8 representative locations during April-June

2013. The number of monitoring stations and parameters for monitoring were based on the

approved ToR obtained from MoEF. The ambient air quality locations are shown in Figure

3.6 rationale for selection of the monitoring locations is presented in Annex 3.2.

Air quality monitoring was carried out for 2 months at the pre-monsoon season, 24 hours a

day twice a week for PM10, Sulphur Dioxide (SO2), Nitrogen di oxide (NO2), once a week for

Volatile Organic Carbon (VOCs), methane and non methane hydrocarbon. A respiratory dust

sampler (APM 460 DX, Envirotech Instruments Pvt. Ltd) was used for sampling of PM10,

SO2 and NO2. Benzene sampler (AAS 172, Ecotech Instruments) was used for sampling of

VOC, methane and non-methane hydrocarbon.

Rationale for selection of air monitoring stations

The ambient air quality monitoring locations have been selected based on topography and

prevailing micro-meteorological conditions (downwind, upwind and crosswind directions) to

Photo 3.1: Meteorological Monitoring at Uriamghat



establish baseline ambient air quality in areas likely to be affected the exhaust emissions from

DG sets, movement of vehicles, fugitive emissions from material stockpiles and from

sourcing & transportation of raw materials during project construction phase. Flaring of gases

under emergency situation during operational phase has also been considered in this regard.

A screening model was run before the selection of the station with SCREEN 3 and it was

found that the maximum GLC was found to be within 2 km of the well sites considering all

stability classes. Monitoring locations were selected based on upwind, downwind and

crosswind directions within 2 km of the proposed well sites at receptors that are likely to be

affected by the drilling operations. Two monitoring locations Padampathar and Jamuguri was

selected outside the block to capture the effect of movement of vehicles and other activities

within the Block. Other considerations like location of receptors (settlements), accessibility to

the monitoring location, availability of stable electric connection for running of RDS and

safety and security of machine and monitoring personnel were also considered while

selecting the monitoring locationsThe concentrations of various pollutants were processed for

different statistical parameters like arithmetic mean, minimum concentration, maximum

concentration and percentile values. The detailed ambient air quality results are presented in

Annex 3.3.

Interpretation of Air Quality Results

Particulate Matter (PM 10): The average of 24 hourly PM 10 at the monitoring locations ranged

between 50.21-70.07 μg/m3 (Figure 3.3). The average PM10 concentrations were observed to

be in compliance to the NAAQS (100 μg/m3) at all air quality monitoring locations. The results

of PM10 levels at the monitoring stations have been represented in Annex 3.3.



FIGURE 3-3: AVERAGE NO2 VALUES AT THE MONITORING LOCATIONS

Nitrogen dioxide (NO2): The average NO2 values at the monitoring locations were observed in

the range of 19.79-24.21 μg/m3 (Refer Figure 3.4). The average values complied with the

NAAQS (80 μg/m3) specified for nitrogen dioxide. The results of PM10 levels at the monitoring

stations have been represented in Annexure 3.3.

Sulfur dioxide (SO2): Sulfur dioxide concentrations at all locations was found to be below

detectable limit i.e. <4 μg/m3 (Refer Annex 3.3). Low values of SO2 can be attributed to the

primarily rural setting of the block.

Methane and Non- Methane Hydrocarbon: Mean values for methane and non methane

hydrocarbons at the sampling stations varied between 1.29-2.97 ppm and 0.26-0.73 ppm

respectively. Hydrocarbon contents at the ambient air samples were higher at all the stations as

the stations are within the producing hydrocarbon fields. The average methane and non

methane hydrocarbon values at the monitoring stations are provided at Table 3.1.

Volatile Organic Carbon (VOCs): Mean values of VOC varied between 0.18-2.96 ppm. Higher

mean values were recorded for Lakhinagar, Bidyapur, Jamuguri and Padampathar. The average

volatile organic carbon at the monitoring stations is provided at Table 3.1.

Detailed results are presented at Annex 3.3.

0

20

40

60

80

100

120

Near

Haldibari

Secondary School

Haldibari

Village

Near Haldibari

Bamchuk

Primary School

Gholapani

Village

Lakhinagar

Village

Bidyapur

Village

Padampathar

Village

Jamuguri

Village

mic

rogr

ams

pe

r cu

bic

me

ter

Monitoring Locations

PM10 (µg/m3) NAAQS



FIGURE 3-4: AVERAGE NO2 VALUES AT THE MONITORING LOCATIONS

Photo 3.2: Air Monitoring at Gholapani

TABLE 3-1: AVERAGE HYDROCARBON AND VOC MONITORING DATA

Sl.

No Monitoring Locations

Methane

hydrocarbon

(ppm)

Non-methane

hydrocarbon

(ppm)

VOC

(ppm)

1 Near Haldhibari Secondary School 2.13 0.63 0.55

2 Haldhibari Village 1.29 0.26 0.18

3 Near Haldhibari Bamchuk Primary School 1.94 0.50 1.15

4 Gholapani Village 2.11 0.50 1.59

5 Lakhinagar 2.75 0.73 2.96

6 Bidyapur Village 2.27 0.49 2.26

0

10

20

30

40

50

60

70

80

90

Near

Haldibari

Secondary School

Haldibari

Village

Near

Haldibari

Bamchuk Primary

School

Gholapani

Village

Lakhinagar

Village

Bidyapur

Village

Padampathar

Village

Jamuguri

Village

mic

ro

gra

ms

per c

ub

ic m

ete

r


NO2 (µg/m3) NAAQS



Sl.

No Monitoring Locations

Methane

hydrocarbon

(ppm)

Non-methane

hydrocarbon

(ppm)

VOC

(ppm)

7 Padampathar Village 2.47 0.52 2.11

8 Jamuguri Village 2.97 0.58 2.06

3.1.3 Ambient Noise Quality

The ambient noise monitoring was conducted during the pre-monsoon season at 6 locations

within the Khoraghat Extension ML Block. Noise stations were selected near to the proposed

well locations to understand the baseline noise levels that could be impacted upon by the

proposed drilling activities at the Field. Noise monitoring was conducted at Bidyapur (NQ 1),

Gholapani (NQ 2), Near Haldhibari Bamchuk Primary School (NQ 3), Haldhibari Village

(NQ 4), Near Haldhibari Secondary School (NQ 5) and Chetanapur (NQ 6).

Sound pressure level (SPL) measurements in dB (A) were recorded for every hour

continuously for 24 hours at 15 minutes interval for the monitoring stations and equivalent

noise levels in the form of Leq day and Leq night was computed. The results obtained were

compared with the standard specified in Schedule III, Rule 3 of Environmental Protection

Rules2. The ambient noise quality monitoring locations within the study area are shown in

Figure 3.6 and the rationale for selection of the stations has been presented in Annex 3.2.

Interpretation of Noise Quality Results

The day time equivalent noise levels at the monitored stations were found to be ranging

between 44.3-47.3 dBA and in compliance to the day time noise standards (55 dBA) for

residential areas (Refer Figure 3.5). The night time noise levels for the sites (maximum 37

dBA) were also found to be within the night time standards specified for residential area (45

decibels). The detailed noise monitoring results are presented in Annex 3.4.

Low noise levels at all the monitoring stations were primarily due to existing rural settings of

the locations. The monitoring location in proximity to Khoraghat GGS-1 (Chetanapur) and

GGS-2 (Gholapani) also did not reveal higher noise values.

2 Sound Level Meter: SL 4001, Lutron & SLM 100, Envirotech CPL-4, 11



FIGURE 3-5: DAY AND NIGHT TIME EQUIVALENT NOISE LEVELS

0.0

10.0

20.0

30.0

40.0

50.0

60.0

Bidyapur Gholapani Near Haldhibari Bamchuk

Primary School

Haldhibari Village

Near Haldhibari Secondary

School

Chetanapur

Equ

ival

ent

No

ise

Leve

ls in

db

A


Ld Ln Daytime standard Nighttime standard



FIGURE 3-6: LOCATION OF AIR, NOISE, METEOROLOGY AND TRAFFIC MONITORING LOCATIONS WITHIN THE KHORAGHAT EXTENSION ML BLOCK



3.1.4 Physiography and Geology

The physical features and geology are closely related. Based on the physical features and

geology, the north east of India and more specifically, the State of Assam can be divided into

following physical divisions (structural units):

Brahmaputra valley - The Brahmaputra Valley is of the nature of a “ramp” valley

developed during the simultaneous upheaval of the Himalayas on the north and north

east and the Patkai ranges on the south and south east. The vast alluvial plains of

Brahmaputra valley occupy most of the North Assam covering Goalpara, Kokrajhar,

Dhubri, Kamrup, Nalbari, Barpeta, Nagaon, Darrang, Sonitpur, Sibsagar, Jorhat,

Golaghat, Lakhimpur and Dibrugarh districts. The Brahmaputra valley is bounded by

Arunachal Himalaya in the north and northeast, Patkai – Naga - Lushai range of

Nagaland and the Shillong Plateau in the south and southeast.

Central Assam Hills -The Central Assam which essentially is a hilly terrain comprised

of Mikir Hill in Karbi Anglong and North Cachar Hill districts.

Barak valley - The hilly and alluvial terrain in the south covering the Cachar and

Karimganj districts in the Barak (Surma) valley.

Golaghat district lying in the Brahmaputra Valley is surrounded by the river Brahmaputra to

the north, the state of Nagaland to the south, Jorhat district to the east and Karbi Anglong and

Nagaon district to the west. Physiographically, Golaghat district shows a plain topography

towards north and southeast, while the southwestern part of the area represents an undulating

topography. The general elevation of the area is around 100 meters above Mean Sea

Level(MSL) and low lying areas show altitude about 80 m above MSL. Maximum height of

about 128 m above MSL is observed in the southern parts of the district, where it merges with

the hills of the Nagaland as well as Karbi-Anglong district of Assam. The slope of the district

is towards north east from south. The Khoraghat Extension ML Block also has an undulating

topography (Figure 3.7). The general slope of the Block is from South to North. The rivers

Dayang and Rengma flow from south to north.

Geology

The State of Assam is occupied by rocks belonging to, (a) Proterozoic Gneissic Complex, (b)

Shillong Group of Meso-Palaeo Proterozoic age, (c ) Granite Plutons of Neo-Proterozoic-

Lower Palaeozoic age, (d) Lower Gondwana sedimentary rocks of Permo-carboniferous age

(e) Alkali Complexes of Samchampi, Borpung and volcanic rocks represented by Sylhet Trap

of Cretaceous age, (f) Lower Tertiary (Paleocene-Eocene) shelf sediments of the Jaintia

Group extending along the southern and eastern flanks of Mikir Hills and geosynclinals

sediments of Disang Group in parts of the North Cachar Hills, (g) Upper Tertiary (Oligocene

to Pliocene) shelf and geosynclinal sediments covering the southern flanks of Mikir Hills, the

North Cachar Hills and the hills of the Cachar district in the Surma valley area. These rocks

are also exposed along the northern foothills of Naga-Patkai range bordering the southern



margin of Sibsagar, Jorhat and Dibrugrah districts. Along the southern foothills of Eastern

Himalaya facing the northern border of Assam a narrow strip of Siwalik rocks are exposed

(h) the Quaternary deposits comprising of Older and Newer Alluvium occur in flood plains

and terraces of the Brahmaputra valley, Surma valley and other river basins of Assam.

Geological Setting of the Block

The Khoraghat field lies in the southern fringe of Upper Assam in Dhansiri Valley. Previous

drilling activities of ONGC penetrated from Alluvium to Basement through Neogene (Moran,

Tipam and Bokabil) and Paleogene (Barails, Kopili, Sylhet and Tura) sequences. Bokabil

formation lying unconformably above the Batail group of late Eocene to Oligocene age

represents the Surma Group, in Dhansiri valley. In this area, all the pay sands are mainly

confined between Barail top unconformity and an erosional surface above lower Bokabil.

FIGURE 3-7: TOPOGRAPHIC MAP OF KHORAGHAT EXTENSION ML BLOCK



3.1.5 Hydrogeology

The hydrogeological environment and ground water regime conditions in the Brahmaputra

basin indicate the existence of potential aquifers having enormous fresh ground water

reserves. The area is covered by alluvial sediments of river basins constituting the

unconsolidated formations of sandstone, shale, limestone including conglomerate of the

Coenozoic, Mesozoic and Upper Palrozoic era in the Brahmaputa Basin. These are very

significant ground water reservoirs for large scale and extensive development. Ground water

occurs under water table to confined conditions. Depth to water level in major parts of

Golaghat district varies from 2 to 5 m. In the extreme southern and southwestern parts close

to hills, the water level is found to be deeper and generally rests within 5 to 7 m. The

movement of ground water is from south to north. The water level trend shows that there is

gradual rising of water level in the district.

(Source: Dynamic Ground Water Resources in India, as on 31st March, 2009, CGWB; Ground water quality in

Shallow aquifers of India, 2010)

Ground Water Resources

Assam is one of the rich states of the country in term of the ground water development

potentiality. The entire Brahmaputra valley covers more than 70 per cent of the total

geographical area of the state, containing prolific aquifer system with water table lying within

5 m of land surface. The district possesses good potentiality for ground water development.

Bestowed with high incidence of rainfall and covered by a thick pile of porous sediments,

these ground water reservoirs get replenished every year and are being used heavily. In these

areas, in addition to the Annual Replenishable Ground Water Resources available in the zone

of Water Level Fluctuation (Dynamic Ground Water Resource), there exists a huge ground

water reserve in the deeper passive recharge zone below the zone of fluctuation as well as in

the deeper confined aquifers which is nearly unexplored.

3.1.6 Ground Water Quality

Groundwater is primarily tapped by tube wells from depths ranging mostly between 20-35 m.

The analytical report of water ground water samples collected by CGWB revealed that

ground water is suitable for domestic, irrigation and industrial purposes. Ground water from

shallow aquifer is slightly alkaline whereas ground water from deeper aquifer is slightly

acidic in nature. High concentration of iron and arsenic beyond permissible limit in ground

water in some areas in Golaghat District was also reported.

(Source: Dynamic Ground Water Resources in India, as on 31st March, 2009, CGWB; Ground water quality in

Shallow aquifers of India, 2010)

Primary monitoring of ground water quality was considered important in order to understand

the probable impacts of the proposed project activities on the sub surface aquifers. Due to

rocky nature of the area groundwater is primarily extracted from the dug wells in the Block.

Potential pollution of subsurface and unconfined aquifers may occur due to improper casing



and cementing of well leading to infiltration or seeping of drilling chemicals or mud into

nearby aquifer. Contamination of aquifers may also occur from disposal of drilling waste and

mud in an open/unpaved pit.

A monitoring network consisting of 4 locations for groundwater was selected and

representative sampling was carried out at each of the locations (Refer Figure 3.8) and the

detailed results of ground water analysis are presented in Table 3.2.

Ground Water Sampling Points

A total of four ground water samples were collected from dug wells and tube well located in

proximity to the proposed drill sites. The samples were collected from Haldhibari Village,

Gholapani Village, Chetanapur Village and Haldhibari Bamchuk Primary School. Samples

were analyzed for physicochemical and bacteriological parameters and results compared with

IS: 10500: 2012 drinking water standards to identify and interpret any deviation in the

statutory limits set for parameters under this standard.

Interpretation of Ground Water Quality Results

pH

pH of the groundwater sample collected from Haldhibari village (6.4) was found to be

slightly lower than the IS:10500 limit of 6.5. However, pH values of all the other

groundwater samples (6.9-7.2) were found to be in compliance to the limit of IS:10500:2012

standard (6.5-8.5).

Colour and Odour

All the groundwater samples were found to be colourless in nature and revealed colour values

less that 1 Hazen unit which were in compliance to the acceptable limit of 5 Hazen unit. All

the samples revealed unobjectionable odour values.

Turbidity

Turbidity values for ground water samples varied between 8.2-56.2 NTU and exceeded both

desirable and permissible (in absence of an alternate source) limits specified under this

standard i.e. 5 NTU and 10 NTU respectively. High turbidity therefore could possibly result

in the decrease in the acceptability of such water for potable purposes.

Chlorides and Total Dissolved Solids

With respect to IS: 10500 standards the desirable limit of chloride is 250 mg/l while the

permissible limit of the said parameter (in absence of alternate source) is 1000 mg/l. At

concentration above 250 mg/l chlorides renders a salty taste to water which may be

considered to be objectionable in terms of human consumption.

The chloride concentration in the ground water samples of the study area villages have been

found to be well within the stipulated standards ranging from 3.8 mg/l at Gholapani and 34.2

mg/l at Haldhibari Village.



The concentration of total dissolved solids (TDS) in ground water is a measure of its

suitability for domestic use. In general, TDS values at 500 mg/l or below is considered to be

most desirable for such purpose being specified under IS: 10500 drinking water standard. The

TDS values for the ground water samples analyzed varies in the range of 102.26 mg/l

(Chetanapur) to 202.16 mg/l (Gholapani) thereby conforming to the desirable limit of this

ground water parameter.

Total Hardness

Hardness of water is considered to be an important parameter in determining the suitability of

water for domestic uses particularly washing. Hardness of water is correlated to the presence

of bivalent metallic ions viz. calcium and magnesium. Total hardness values for the ground

water samples analyzed ranged between 62.4 mg/l (Chetanapur) to 145.6 mg/l (Haldhibari

Bamchuk Primary School) and were found to be within the stipulated standard of 200 mg/l

specified under IS: 10500. Further as discussed above, the hardness values recorded at each

ground water monitoring station was found to be in correlation with the calcium and

magnesium ions analyzed for such samples. The concentration of calcium and magnesium

ions was found to be within both desirable and permissible limits specified for the aforesaid

parameters as per IS: 10500 standards.

Iron and Fluoride

Iron is considered to be an important ground water parameter since at higher concentration it

interferes with laundering operations and imparts objectionable stains. Iron concentration of

all the ground water samples (1.06-7.03 mg/l) were found to be exceeding the limit specified

at the IS:10500, 2012. High iron content recorded at the groundwater samples is probably due

to local geological features and was also reported by CGWB Groundwater Booklet for

Golaghat District. Fluoride contents in the ground water samples were found to be in

compliance to the desirable limit of the drinking water standard of 1.0 mg/l.

Heavy Metals

The presence of heavy metals like mercury (< 0.001 mg/l), arsenic (< 0.01 mg/l), copper (<

0.02 mg/l), lead (<0.005 mg/l), hexavalent chromium (<0.05 mg/l) and cadmium (< 0.002

mg/l), in the ground water samples of all the four sources were found to be below detection

limits.

Total Coliforms

Coliforms are indicators of contamination from sewage and faecal matter. Total coliforms

were present in all collected samples and in the concentration of 50 MPN/100ml in

Haldhibari Village, 160 MPN/100ml in Chetanapur, 50 MPN/100ml in Gholapani and

130MPN/100ml in Haldhibari Bamchuk Primary School. Faecal coliforms were also detected

in 2 out of 4 samples for Haldhibari Village and Chetanapur. The dug well at Chetanapur did

not have a parapet. There is a chance of runoff from other areas reaching the well, which

could be the case of very high total coliform and presence of faecal coliform in that well.



The analyzed groundwater samples reveal higher turbidity values and iron contents. The

samples were also found to reveal presence of organic pollution reflected by the presence of

faecal coliform (except Haldhibari Bamchuk Primary School) and high total coliform content

in all samples. People in the area generally filter (viz. with sand filter) and boil the water

before consumption. It was revealed during discussion with local villagers that stomach

related problem is common in the area.

Photo 3.3: Groundwater sampling at Haldhibari Photo 3.4: Groundwater sampling from Chetanapur

Photo 3.5: Groundwater sampling at Gholapani Photo 3.6: Groundwater sampling from Haldhibari

Bamchuk Primary School



TABLE 3-2: GROUNDWATER MONITORING RESULTS

Sl No. Parameters Unit

IS: 10500: 2012 Monitoring Locations

Required

(Acceptable

Limit)

Permissible

limit in the

absence of

alternative

source

Dug well

Haldhibari

village

Dugwell at

Chetanapur

Tube well

Gholapani

village

Dug well

Haldhibari

Bamchuk

Primary

School

1. pH at 250C

---- 6.5-8.5 No relaxation 6.4 7.1 7.2 6.9

2. Colour Hazen 5 15 <1.0 <1.0 <1.0 <1.0

3. Odour ---- Agreeable Agreeable Unobjectionable Unobjectionable Unobjectionable Unobjectionable

4. Turbidity NTU 1 5 15.2 56.2 21.5 8.2

5. Total Hardness as

CaCO3 mg/l 200 600 137.28 62.4 133.12 145.6

6. Calcium as Ca mg/l 75 200 19.97 4.99 23.3 19.97

7. Magnesium as Mg mg/l 30 100 20.96 11.98 17.96 22.96

8. Alkalinity mg/l 200 600 90 49.5 189 103.5

9. Chlorides as Cl mg/l 250 1000 34.2 15.2 3.8 23.99

10. Sulphate as SO4 mg/l 200 400 29.7 11 <1.0 13.7

11. Nitrate as NO3 mg/l 45 No relaxation 7.67 <0.5 0.81 1.38

12. Copper as Cu mg/l 0.05 1.5 <0.02 <0.02 <0.02 <0.02

13. Iron as Fe mg/l 0.3 1.06 5.65 2.53 7.03

14. Fluoride as F mg/l 1.0 1.5 0.17 0.15 0.43 0.16

15. Zinc as Zn mg/l 5 15 <0.02 <0.02 0.029 <0.02

16. Phenolic Compound

as C6H5OH mg/l 0.001 0.002 <0.001 <0.001 <0.001 <0.001



Sl No. Parameters Unit

IS: 10500: 2012 Monitoring Locations

Required

(Acceptable

Limit)

Permissible

limit in the

absence of

alternative

source

Dug well

Haldhibari

village

Dugwell at

Chetanapur

Tube well

Gholapani

village

Dug well

Haldhibari

Bamchuk

Primary

School

17. Mercury as Hg mg/l 0.001 No relaxation <0.001 <0.001 <0.001 <0.001

18. Cadmium as Cd mg/l 0.003 No relaxation <0.002 <0.002 <0.002 <0.002

19. Arsenic as As mg/l 0.01 0.05 <0.01 <0.01 <0.01 <0.01

20. Lead as Pb mg/l 0.01 No relaxation <0.005 <0.005 <0.005 <0.005

21. Hexavalent

Chromium as Cr+6

mg/l

0.05 (for

Total

Chromium)

No relaxation <0.05 <0.05 <0.05 <0.05

22. Total Dissolved

Solids mg/l 500 2000 190.97 102.26 202.16 162.4

23. Total Coliform

Organism (MPN/100ml)

Shall not be detectable in any 100

ml sample 50 160 50 130

24. Faecal Coliform In 100ml Shall not be detectable in any 100

ml sample Present Present Absent Absent



FIGURE 3-8: LOCATION OF GROUNDWATER, SURFACE WATER AND SOIL MONITORING LOCATIONS WITHIN THE KHORAGHAT EXTENSION ML BLOCK



3.1.7 Watershed and Drainage

The Golaghat District is situated at the plans of the Brahmaputra Valley. The entire eastern

boundary of the District is flanked by the Naga Patkoi hills. These hills form the bed for the

origin of several streams due to the high rainfall in these regions. The streams flow down to

the plains of the district and join to form several rivulets and rivers that ultimately join River

Dhansiri which is a major tributary of River Brahmaputra. Other rivers and rivulet flowing in

the district are Kakodonga, Mokrong, Dayang etc. These rivers have meandering courses

with abandoned channels in the form of bils and ox-bow lakes along their courses. The

Khoraghat Block lies in the catchment of Dhansiri though it does not pass through the Block.

The major rivers traversing the Khoraghat Block are Dayang and Rengma. The drainage

pattern of the major rivers traversing the study area is discussed below.

Dhansiri River

River Brahmaputra and its tributary Dhansiri are the main rivers of the Golaghat District. The

catchment area of Dhansiri River is 1220 km². It originates from Laisang peak of Nagaland. It

flows through a distance of 352 km from south to north before joining the Brahmaputra on its

south bank. Dayang, Nambor, Doigrung and Kalioni are the four major tributaries of the

Dhansiri. Dhansiri River flows in the western part of the study area and the closest distance

from the Block is approximately 7 km.

Dayang

It is the longest and the largest river in the Lotha- Naga area. It runs through the foot hills of

the Japhu Mountain, the highest mountain range in Nagaland, across the western part of

Lotha area, and flows down to the plains of Assam. The Dayang River flows along the

eastern boundary of the Block from south to north.

Rengma River

Rengma River is the main tributary of Dayang River. It also originates from the Naga-Patkai

hills and enters the Block from the south. It flows along the western side of the Block from

south to north and meets Dayang River about 3 km north of the Block.

All these major channels are perennial in nature and were found to contain water even at the

summer period. There are also several small channels which contribute to these channels but

majority of them were found dry during the survey period. These surface water channels

within the Block are primarily used for irrigation, bathing, washing and for catching fish.

Surface water runoff and discharge of drilling wastewater from the proposed developmental

well sites are most likely to reach the Rengma River and also Dayang River via. some minor

surface water channels and have the potential to affect the water quality of these channels.

The drainage map of the study area is presented in Figure 3.9



FIGURE 3-9: DRAINAGE MAP



3.1.8 Surface Water Quality

Primary monitoring of surface water quality was given importance during scoping of the EIA

study as the effluent generated during the development well drilling operations are likely to

be discharged to nearby surface water bodies/natural drainage channels/rivers after ensuring

that it meets prescribed norms of CPCB. Further, an effort has been made to establish the

baseline quality of the existing major watersheds to identify any possible contamination due

to any current industrial activities. A monitoring network consisting of 4 locations for

surface water monitoring were selected and representative sampling was carried out in each

of the locations. Water sampling and analysis3 was done following CPCB standard guidelines

for physical, chemical and bacteriological parameters. The monitoring locations are shown in

Figure 3.8.

Surface Water Sampling Points

Surface water samples were collected from Dayang and Rengma Rivers to get an overview of

the surface water quality of the study area. Two samples each were taken from both the

rivers. One sample was taken upstream (south) to the proposed well sites and another was

taken downstream (north) of the proposed well sites. Surface water quality was finally

assessed against water quality criteria as per CPCB guidelines for water resources. Results of

surface water samples have been discussed below.

Interpretation of Surface Water Quality Results

The pH of the surface water samples varied from 6.8-7.5. The DO levels at the Dayang River

Samples varied between 6.7-7.4 mg/l indicating favorable conditions for the growth and

reproduction of normal population of fish and other aquatic organisms. However, samples

collected from the Rengma River showed lesser DO values, 5.5 mg/l in Rengma-upstream

sample and 3.5 mg/l at Rengma-downstream sample.

BOD values in all the surface water samples were detected at concentration below 2.00 mg/l

for all the samples excepting Rengma-downstream sample (4.7 mg/l). Such low BOD values

confirmed the presence of low concentrations of biologically oxidizable organic matter in the

receiving water bodies. Higher BOD values at the Rengma-downstream sample (4.7 mg/l)

could be due to mud laden surface run-off received by the stream from the local catchment

areas. COD values for all the surface water samples were found to be less than 4 mg/l

excepting the Rengma-downstream sample which showed COD value of 23.4 mg/l.

Electrical conductivity values of the samples ranged between 137.75-197.6 millisiemens/cm,

sodium absorption ratio varied between 0.39-0.64. Free ammonia contents of all the samples

were found to be less than 0.1 mg/l.

3 http://www.cpcb.nic.in/latest/guidelines-water.doc



The total coliform count of the surface water samples varied between 14 MPN/100ml at

Dayang-upstream, 9 MPN/100ml at Dayang-downstream, 80 MPN/100 ml in Rengma-

upstream and 130 MPN/100 ml in Rengma-downstream sample.

The presence of contaminants in the form of oil and grease and heavy metals viz. lead, iron,

arsenic, chromium and mercury in the surface waters of all sources were found to be

negligible. The toxic organic component, phenol, was also found be below detectable limit

(<0.001 mg/l) in all the surface water samples.

Detailed surface water analysis results have been provided at Table 3.3.

As discussed in the previous section the channels from which samples were taken and

analyzed were primarily used for irrigation, bathing, cleaning and for catching fish. The

analyzed values of the river water samples after comparing with the CPCB Water Use

Criteria (Class B, Class D, Class E) (Refer Annex 3.5) justifies their use in compliance to

water use criteria.

TABLE 3-3: SURFACE WATER QUALITY RESULTS

Sl.

No. Test Parameters Unit

Dayang

River

Upstream

Dayang

River

Down

stream

Rengma

River

Upstream

Rengma

River

Downstream

1. Temperature 0C 25 28 31 28

2. Free Ammonia as

NH3

mg/l

<0.1 <0.1 <0.1 <0.1

3. pH ---- 7.4 7.5 7.3 6.8

4. Dissolved Oxygen mg/l 6.7 7.4 5.5 3.5

5. BOD ( 3 days at

27⁰C ) mg/l <2.0 <2.0 <2.0 4.7

6. COD mg/l <4.0 <4.0 <4.0 23.4

7. Electrical

Conductivity at

25⁰C

µs/cm 164.16 161.03 197.6 137.75

8. Sodium

Adsorption Ratio ---- 0.39 0.4 0.39 0.64

9. Boron as B mg/l <1.0 <1.0 <1.0 <1.0

10. Oil & Grease mg/l <1.4 <1.4 <1.4 <1.4

11. Total Dissolved

Solids as TDS mg/l 102.83 101.14 126.56 86.67

12. Total Suspended

Solids as TSS mg/l 87.6 80 423.2 3017.2

13. Dissolved

Phosphate as PO4

mg/l <0.15 <0.15 <0.15 <0.15



Photo 3.7: Surface water sampling at Dayang River Photo 3.8: Surface water sampling at Rengma River

3.1.9 Land-Use

The land-use and land-cover of the Block and 10 km from the centre of the Block (study

area) have been interpreted from the satellite data (LANDSAT Imagery), toposheet of the

area (1:250000 scale), and subsequently by ground truthing during field surveys. The Block

is included under the Dayang R. F, Rengma R. F and Nambor R. F. Currently the forested

areas are deforested and used for agricultural activities and human habitation. The land cover

of the Block as conceive currently has been described below;

The Block land cover data showed majority of the land (about 64%) in the area is used for

agriculture purpose with paddy as the primary produce. Settlements comprise about 33% of

the total area of the Block. River Rengma and Dayang comprise of 1.3% of the total Block

area. Roads including PWD roads and other village roads comprise 0.49% of the total Block

area. Drill pads, GGS etc. facilities of ONGC comprise 0.05% of the total area.

Percentage land cover data for the study area revealed 50.6% agriculture land and about 23%

settlement area. About 23% of the study area comprise of forest land, however the entire

stretch of forest land is located outside the Block and in the state of Nagaland. River and

water bodies comprise of about 2.6% of the total study area.

14. Nitrate as NO3 mg/l 1.42 2.02 1.81 1.68

15. Chloride as Cl mg/l 3.99 3.99 1.99 1.99

16. Sulphate as SO4 mg/l 4.2 17 <1.0 <1.0

17. Iron as Fe mg/l 6.56 7.48 26.01 107.3

18. Total Chromium

as Cr mg/l <0.01 <0.01 <0.01 <0.01

19. Phenolic

Compound as

C6H5OH

mg/l <0.001 <0.001 <0.001 <0.001

20. Total Coliform

Organism (MPN/100ml) 14 9 80 130



The percentage distribution categories of land cover of the Block and study area have been

shown in Figures 3.10 and 3. 11 and the land use map are presented in Figure 3.12.

FIGURE 3-10: PERCENTAGE LAND COVER DISTRIBUTION OF THE BLOCK

FIGURE 3-11: PERCENTAGE LAND COVER DISTRIBUTION OF THE STUDY AREA (10 KM AROUND

THE BLOCK)

Out of 2 development wells, KHDE will be located on Rengma Reserve Forest currently used

for agriculture and KHDF will be located within the premise of existing Khoraghat GGS 1

(also in Rengma R. F) of ONGC.

64.16

33.17

0.05 1.30 0.49

0.82

Agriculture Settlement Industry River Road Waterbody

50.65

0.02

23.30

22.98

0.03 2.00 0.38 0.64

Agriculture Canal Forest Settlement Industry River Road Waterbody



FIGURE 3-12: LAND USE-LAND COVER MAP OF KHORAGHAT EXTENSION ML BLOCK



3.1.10 Soil Quality

The major portions of the soils of Assam belong to Inceptisols (49.3%) followed by Entisols

(32.3%), Alfisols (12.3%) and Ultisols (6.1%). The texture of Assam soils varies

considerably depending on the agro climatic conditions and physiographic units. The most

typical characteristics of Assam soil is its acidity. The major parts of the soils of Assam are

acidic in nature having pH ranges 4.2 to 5.8.The soil of flood plains have slightly high pH

(6.0-6.5). The soils of hill zone have higher pH ranging from 6.0 to 7.1. The organic matter

content of Assam soils is medium to high. The available N content has been rated low to

medium in three zones whereas it is medium in the hill zone. The available phosphorus

content ranged from low to medium in three zones of the Brahmaputra valley zone, medium

to high in the Barak valley zone and low in the hill zone. The available potassium content in

the soils varies from low to medium in different zones. High variability in fertility status is

observed between upper and lower Brahmaputra valley. Wide spectrum of fertility status of

the region, in turn, results in vegetative growth potentials in general and cropping pattern in

agriculture pattern in particular, attributing to inherent diversity traits of the region.

The soil of Golaghat district mostly of two types, inceptisol (Old alluvial) and Entisol (recent

alluvial).The texture of surface soil ranges from fine loamy, coarse silty and fine soil. 58% of

total are categorized under fine loamy soil under Inceptisol. The major part of the soils of

Golaghat district is acidic in nature. The organic matter content of soil is medium to high.

The available N is medium and available P and K is low to medium.

(Source: Ground Water Information Booklet Golaghat District, Assam, Ministry of Water Resources,

Guwahati, 2008).

As discussed above, since soils of the Brahmaputra Valley, of which the Block is a part is

characterized by fertile alluvium the implementation of the proposed project may lead to the

temporary change/loss of soil fertility at the drilling site. The understanding of soil quality

therefore assumes significance considering the block soil fertility characteristics and also

given the responsibility of the proponent to restore the site back to its original condition

following decommissioning. An effort has been therefore been made to establish the soil

quality of the block through primary monitoring study as discussed in the section below.

Primary Soil Sampling and Analysis

The soil characteristics within the study area, especially the physical quality and fertility of

the soil have been characterized by analyzing the soil samples collected from agricultural

lands at 5 locations at Chetanapur near GGS-1, Gholapani, near Haldhibari Chariali,

agricultural land near proposed KHDE site and Agricultural land in Haldhibari village. As

described in Section 2.5 that proposed KHDE well will be drilled in agricultural land

emphasis has been given in selection of soil quality monitoring locations in agricultural land.

Primary soil monitoring includes analysis of the heavy metals with the objective of

establishing baseline values for such contaminants. The soil sampling location points are

shown in Figure 3.8.



Interpretation of Soil Analysis Results

The textures of all soil samples collected from agricultural land were found to be clayey in

nature. The sand percentages of the samples were found to be ranging between 15.9-25.8%,

whereas silt percentages of the collected samples were found to be 13.5-22.9%. On the other

hand clay percentages of the soil samples were found to be between 51.3-70.6%. The pH

level in soil samples between 4.69-5.22 indicating strongly acidic soils as per standard soil

classification. Electrical conductivity is used to estimate the soluble salt concentration in soil,

and is commonly used as a measure of salinity. The EC values for soil samples varied

between 57.94-138.27 microsiemens/cm.

The soil samples showed moderate organic carbon content ranging between 0.69-1.15%. The

soil samples revealed high available nitrogen content (317.24-421.01 mg/kg), which is

suitable for paddy cultivation. However, the soil is low in available phosphorus and

potassium content.

Heavy metals viz. iron, copper, zinc and manganese are important soil micronutrients being

considered essential for the normal growth of plants. Deficiencies of micronutrient drastically

affect the plant growth and metabolism. The micronutrient levels of iron (447.22-1070.4

mg/kg), copper (10.94-19.34 mg/kg), zinc (40.78-61.68 mg/kg) and manganese (70-278

mg/kg) observed in the soil samples do not indicate any extraordinary enrichment of metals

or contamination from any external sources and the concentrations agree to the general

natural composition of soils.

The sodium hazard of soil usually is expressed as the Sodium Adsorption Ratio (SAR). Soils

with high levels of exchangeable sodium may cause dispersion of soil particles leading to the

replacement of major cations (calcium and magnesium) adsorbed on the soil. This could

possibly to lead to deterioration of soil structures and water infiltration problems. The SAR

values in the soil samples were found to be varying between 0.07-0.1 which is suitable for

cultivation. Further, soil analysis results exhibits higher concentration of calcium (490-980

mg/kg) ions compared to sodium (80-140 mg/kg). Higher Ca2+

values observed in the

samples are indicative of good soil permeability and structure.

The detailed soil analysis results have been provided at Table 3.4.



TABLE 3-4: SOIL ANALYSIS RESULTS

Factors Unit

Agricultural

land

Near

Chetanapur

Agricultural

land

Near

Gholapani

Agricultural

land

near

Haldhibari

Chariali

Agricultural

land near

proposed

KHDE well

site

Agricultu

ral

land near

Haldhiba

ri

Texture ---- Clay Clay Clay Clay Clay

Moisture % 17.27 20.62 18.62 24.15 20.12

Sand % 23.4 20.4 15.9 19.3 25.8

Silt % 21.7 14.1 13.5 17.5 22.9

Clay % 54.9 65.5 70.6 63.2 51.3

Organic

matter % 1.38 1.55 1.98 1.5 1.19

Alkalinity

as CaCO3 mg/kg 19.2 19.2 19.2 19.2 19.2

Acidity as

CaCO3 mg/kg Nil Nil Nil Nil Nil

Sp.Gravity ---- 2.21 2.29 2.51 2.42 2.37

pH (1:2.5)

at 260C

---- 4.74 5.01 4.69 5.22 5.08

Electrical

Conductivit

y at 25⁰C

us/cm 138.27 75.87 73.26 64.57 57.94

Available

Nitrogen mg/kg 317.24 346.08 346.08 421.01 390.94

Available

Phosphorou

s

mg/kg <3 <3 <3 <3 <3

Available

Potassium mg/kg 20 60 40 20 20

Calcium as

Ca mg/kg 490 490 980 686 588

Magnesium

as Mg mg/kg 4116 2940 4704 3586.8 2446

Chlorides

as Cl mg/kg 220.43 97.97 48.98 48.98 48.98

Sulphate as

SO4 mg/kg 425.86 165.77 256.51 263.87 262.88

Total

Organic

Carbon

% 0.8 0.9 1.15 0.87 0.69

Iron as Fe mg/kg 447.22 724.45 1070.4 722.9 621.26



Factors Unit

Agricultural

land

Near

Chetanapur

Agricultural

land

Near

Gholapani

Agricultural

land

near

Haldhibari

Chariali

Agricultural

land near

proposed

KHDE well

site

Agricultu

ral

land near

Haldhiba

ri

Copper as

Cu mg/kg 10.94 17.24 19.32 15.86 12.14

Zinc as Zn mg/kg 45.38 49.23 61.68 50.48 40.78

Lead as Pb mg/kg 13.8 19 20.4 15.8 13.8

Manganese

as Mn mg/kg 112 278 91.5 92 70

Boron as B mg/kg 0.78 0.54 0.94 <0.5 <0.5

Sodium as

Na mg/kg 140 80 100 120 100

Sodium

Adsorption

Ratio

---- 0.08 0.07 0.07 0.1 0.1

Photo 3.9: Soil sampling near KHDE well site Photo 3.10: Soil sampling near KHDF well site



3.1.11 Natural Hazards

A natural disaster during the life cycle of the

project can have a significant effect on the

functioning of the project in addition to

affecting the local environment in the area and

stressing the availability of resources for the

project. Such disasters also sometimes create

difficulties in access through disruption of

transportation links.

Seismicity & Earthquakes

The study area is located in Zone V as shown in

the Bureau of Indian Standards (BIS) 2000

seismic zone map for India (refer Figure 3.13).

Zone V is defined as region which might

encounter earthquakes of maximum intensity.

The region has experienced a large number of

earthquakes of tectonic origin. The risk probabilities of earthquake are less over the entire

Brahmaputra valley. Two major earthquakes of magnitude 8.7 (occurred in 1897) and 8.6 (in

1950) causing large scale damage to lives and properties in this region. The details of the

earthquakes are given in Table 3.5.

TABLE 3-5: SIGNIFICANT EARTHQUAKES IN ASSAM

Date of

Quake

Location of

Epicentre Remarks

12 June 1897 Near Rangjoli,

Assam

Magnitude M 8.0. This was one of the most powerful

earthquakes in the Indian sub-continent. The quake wreaked

havoc across the present states of Assam and Meghalaya. 1500

people were killed and hundreds more hurt.

15-Aug-50 Indo-China

Border Region

Magnitude M 8.6. This "Independence Day" earthquake was the

6th largest earthquake of the 20th century. Though it hit in a

mountainous region along India's international border with

China, 1500 people were killed and the drainage of the region

was greatly affected.

[Source : Amateur Seismic Centre www.asc-india.org]

Floods

One of the most serious problems of Assam is the occurrence of frequent and widespread

floods. The Brahmaputra and the Barak are the two main rivers, which causes major problem

during the monsoon period every year in the form of floods thereby resulting in bank erosion

and drainage congestion. Large areas are inundated by floods causing heavy loss in terms of

life and property; and also cause extensive damage to standing crops thereby affecting local

livelihood. The flood history of Assam is given in Table 3.6.

FIGURE 3-13: SEISMIC ZONE MAP OF

INDIA

http://www.asc-india.org/



TABLE 3-6: FLOOD HISTORY OF ASSAM

Year Affected Area (lakh ha) Affected Population

(Lakh)

Total Damage (in

Crores INR)

1990 0.488 1.692 74.56

1991 0.997 5.307 191.15

1992 0.213 0.974 26.56

1993 1.348 5.261 0.215

1994 0.053 0.177 0.20

1998 0.972 4.698 700.00

2000 1.000 3.900 244.06

2001 0.200 0.540 11.14

2002 1.960 6.960 210.95

2004 All of the 27 districts,

worst affected districts, Karimganj,

Cachar, Nagaon and Golpara

122.0 NA

It was revealed from the Disaster Management Plan of Golaghat District (2011) that the

entire district if Flood prone. Flood mainly occurs from May to September. The Flood Hazard

Maps of Golaghat District (1998-2007) prepared by National Remote Sensing Agency

(NRSA) showed that Flood primarily occurs in areas abutting the courses of Brahmaputra

and Dhansiri Rivers. Part of the Khoraghat Extension ML Block particularly adjacent to

Rengma River was also shown as flood prone (Figure 3.14). However, both the proposed

development wells were not located at flood prone zones. Consultation with locals also

revealed that occurrence of flood is not pronounced at locations in proximity to these well

sites.



FIGURE 3-14: FLOOD PRONE AREAS OF KHORAGHAT EXTENSION ML BLOCK



3.2 BIOLOGICAL ENVIRONMENT

3.2.1 Introduction

The Golaghat district is rich in biodiversity and has a number of sensitive ecological habitat

like wildlife sanctuary, National Park, Elephant Reserve. The region falls within the Indo-

Burma Hotspot as delineated by the International Union for Conservation of Nature &

Natural Resources (IUCN) and thereby has been accorded international status in terms of

conservation of biodiversity (Refer Box 3.1).

The primary objectives of the biological environment study are:

Assess the vegetation types

Identify common flora & fauna in the study area

Find out rare and endangered floral and faunal species (if any)

Evaluate wildlife habitat of the area and assess impact of the proposed project on

wildlife & their habitats.

Assess impact of the proposed project on agriculture and domestic livestock.

3.2.2 Methodology

Desktop Review and Reconnaissance Survey

A desktop review (published document etc.) was conducted to determine the forest area

(Toposheet and Satellite imagery), vegetation type (Champion and Seth, 1962), floral and

faunal assemblage in the study area. A site reconnaissance visit was conducted on 19th

-20th

April 2013 to identify different ecological habitats, sensitive ecological habitat and also to

identify the targeted study area for baseline survey.

Baseline Survey

Baseline survey was carried out to determine the existing ecological conditions and was

designed to fill any data gaps, and to facilitate an adequate assessment of the project’s

impacts upon ecology and the development of appropriate mitigation measures. Baseline

survey was conducted on 26th

and 28th

May, 2013 for habitat survey, flora & faunal

assemblage, in the study area. Baseline survey has two part- (i) Secondary data collection and

(ii) Primary Survey.

Secondary Data Collection

Secondary baseline data regarding sensitive ecological habitat (National Park, Sanctuary,

Ecological Sensitive Area, Migratory Corridor, etc.), flora & fauna in the study area, forest

cover was collected for Forest Department’s website; and other publish and unpublished

documents. Stakeholder consultations (Forest Department, Local People, Panchayat, etc)

were also carried out to understand the major flora & fauna in the study area, pressure on

forest resources, presence of any Schedule I species.



3.2.3 Primary Survey

Primary survey was carried out the targeted study area for habitat (terrestrial and aquatic),

flora and faunal survey (terrestrial and aquatic). Special attention was paid to those areas,

which will be directly impacted by proposed oil & gas drilling activity.

Box 3.1: Biodiversity of Indo-Burma Hotspot

The proposed oil field falls under Indo- Burma hotspot, which is one of the twenty-five richest biodiversity

hotspots of the world. The Indo-Burma hotspot comprises about 2

million square kilometers of tropical Asia, east of the Indian sub-

continent. The region includes all of Cambodia, Laos, nearly the

entire territories of Thailand, Myanmar and Bhutan, parts of Nepal,

far eastern India and extreme south China, Hanian Islands in South

China sea and Andman Islands. The region is still revealing its

biological treasurers.

A wide diversity of ecosystem is represented in this hotspot

including mixed wet evergreen, dry evergreen, deciduous, and

montane forests. There are also patches of shrub lands some

coastal areas. In addition, a wide variety of distinctive, localized

vegetation formations occur in Indo-Burma, including lowland

floodplain swamps, mangroves, and seasonally inundated grasslands.

A conservative estimate of total plant diversity in the hotspot

reveals about 13,500 vascular plant species, of which about 7,000

(52 percent) are endemic. Among the flora of the Indo-Burma

Hotspot are a wide array of orchid and ginger species and many

tropical hardwood trees, including commercially valuable

dipterocarp species and teak (Tectona grandis).

There are about 430 mammal species in the hotspot; more than 70

species and seven genera are endemic. Six large mammal species

have been discovered in the last 12 years. Indo-Burma hosts many

endemic primate species, including three species of douc.

Nearly 520 reptile species are found in the hotspot; 12 genera

and over 200 species are endemic. Nine of the endemic genera

are represented by a single species. Indo-Burma also supports

probably the highest diversity of freshwater turtles in the

world: 53 species, representing one-fifth of the world's species

There are more than 280 amphibian species in the Indo-Burma

hotspot, over 150 of which are endemic. However, high

endemism does not extend to the genus level; only three of 46

genera are restricted to the hotspot.

Indo-Burma has a remarkable freshwater fish fauna, with more than 1,260 documented species, or about 10

percent of the world’s freshwater fishes. More than 560 of these species are endemic.

The Hoolock Gibbon (Bunopithecus hoolock) is the only ape species in India, is the western most of the nine

species of lesser apes in South-east Asia. Its distribution is restricted to the monsoon and evergreen rain forests

of Northeast India south of Brahmaputra River, Bangladesh, Southern Yunnan and Myanmar up to the river

Chindwin. Gibbons inhabit primary evergreen and less seasonal parts of semi-evergreen rain forest, and very

rarely semi- deciduous forests.



3.2.4 Terrestrial Ecosystem

Forest Resources

Forest Resources: The Khoraghat Extension ML Block (approximately 83 sq. km) falls under

Golaghat district. Golaghat district has 525 sq. km under the forest cover, i.e. 14.99 percent

of its total geographical area (Source: State of Forest Report 2011, FSI). The forest cover of

the district comprises of 6.0 km2 very dense forest, 122 km2 moderately dense forest and 397

sq. km of open forest.

The original forest area in the Golaghat district is 1334.08 km2 of the 3588 km

2 of total

geographical area of the district. Kaziranga National Park (380 km2) and the Panbari RF (12

km2) are well protected. Reserve forests like Dayang, Rengma, Diphu, and Nambor South,

have been totally deforested and encroached during 1974-2004 and currently only 3.38% of

forest cover exists in Dayang RF, 4.86% in Rengma RF, 1.97% in Diphu RF and 0.07% in

Nambor South RF (Source: A Geo-Spatial Assessment of Habitat Loss of Asian Elephants in Golaghat

District of Assam, Gajah 28 (2008) 25-30).

The Khoraghat Extension ML Block falls under Dayang Reserve Forest, Rengma R. F and

Nambor South R. F. However, entire forest area was deforested and encroached; currently

land has been used for human habitation and agriculture and other amenities and

infrastructure. There is no natural forest in the entire Block.

Forest Land for Proposed Activity

The proposed wells are located in the Rengma Reserve Forest area. During survey, no natural

forest vegetation was observed; the proposed lands were either used for agriculture or are

ONGC’s existing facility (GGS 1 for KHDF). The construction of drill site and approach

road (from access road to drill site) would not required any tree felling. However, ONGC has

already submitted the forest diversion proposal to Forest Department as per Forest

(Conservation) Act, 1980.

Vegetation Types

The entire Block has no natural forest vegetation cover, through included under Dayang,

Rengma and Nambor South R. F. However, the foothill of Nagaland side has some natural

forest. The important forest types found in study area (Source: Forest Types of India 1962 by

Champion and Seth) are:

Moist semi-evergreen forests

Moist Mixed Deciduous forests

Moist Semi-evergreen forests are widely prevalent in the study area and have commercially

important species like Badam, Amari, Cham, Tita Sopa, Nahar, Bhelu, Gomari, Poma,

Bonsum, Dhuna, Myrobalans, Bhola, etc.



Moist Mixed Deciduous Forests have Haldu, Bohera, Simul, Ghogra, Azhar, odal, Outenga

etc. in the top canopy.

A number of plant species were also recorded in the block. Tree species in these sites are

mostly planted and few are natural. The village woodlot, road side plantation and riparian

vegetation were recorded in the study area, these are as follows:

Village Woodlot: Naturally or planted trees on community or private land. Bamboo and

timber woods are planted in this area. Some important tree species are Mangifera indica,

Aegle mermelos, Delonix regia, Dalberjia sisso, Ficus religiosa, Ficus bengalensis, Gmelina

arborea etc.

Road side Plantation: Trees planted along the major roads in the study area. Some important

tree species are Alistonia scholaris, Anthrocephalus sinensis, Azadirchta indica, Acacia

auriculoformis, Artocarpus heterophyllus, Delonix regia, Phyllanthus embilica, Ficus

religiosa, Mangifera indica.

Riparian Vegetation: Vegetation along river bank, major plant species are Anthocephalus

sinensis, Alistonia scholaris, Bombax ceiba, Terminalia arjuna, etc.

3.2.5 Floral Diversity

There are different varieties of flora and fauna in the forests of the state of Assam. The north-

east including Assam has 6000-7000 plant species identified so far. Plant resources of Assam

are concentrated mainly in the tropical and semi-evergreen forests, grasslands, wet deciduous

and riverside forests. There are at least 100 varieties of orchids available in Assam.

The important plant species recorded in the study area were Albizia lebbeck, Aegle marmelos,

Areca catechu, Titachapa (Michelia champaca), Sonaru (Cassia fistula), Simul (Bombax

ceiba), Dillenia indica, Gmelina arborea, Phyllanthus embilica, Terminalia arjuna, Bhelu

(Tetrameles nudiflora). Various types of bamboos, cane groves, tall grasses and other

herbaceous and shrubby vegetations are found in the study area.

During the terrestrial plant survey, about 106 numbers of plant species was recorded,

which includes 51 species of trees, 27 species of shrubs, 19 species of herbs and 9 species

of climbers. The detailed listing of floral species recorded in the study area is given in Annex

3.6.

3.2.6 Endemic, Threatened & Endangered Floral Species

The Wildlife (Protection) Act 1972 prohibits picking, uprooting, damaging, destroying,

acquiring or collecting six species of plants from forest land and any area specified, by

notification, by the Central Government [Clause 17A of Chapter IIIA (Protection of Specified

Plants), page 346 of Handbook Vol. 1]. The six species are: Beddome’s cycad (Cycas

beddomei), Blue Vanda (Vanda coerulea), Kuth (Sassurea lappa), Ladies slipper orchids

(Paphiopedilum spp.), Pitcher plant (Nepenthes khasiana), Red Vanda (Rananthera

imshootiana). None of these species is recorded in the forests of the study area during the

EIA.



3.2.7 Wildlife Habitat

A habitat survey was carried out both in the Khoraghat Extension ML Block and its

immediate vicinity. Assam is home to a number of charismatic mammalian fauna Rhino,

Elephant, Tiger, Pygmy hog, Hispid hare, Golden langur, Leopard, Golden Cat, Clouded

leopard, Himalaya palm civet, Binturong, Himalayan black bear, Sloth bear, Gaur, Water

buffalo, Sambar, Hog deer, Barking deer, Swamp deer, etc. Wildlife in Assam is given

protection through a network of five National Park, 18 Wildlife Sanctuaries (2 proposed

Wildlife Sanctuaries), three Tiger Reserves and five Elephant Reserves.

The Golaghat and adjoining Karbi Anglong districts represent very rich biodiversity. The

Kaziranga National Park lies in Golaghat and Karbi Anglong district. The Nambor-Doigrung

Wildlife Sanctuary (97.15 km2), Garampani Wildlife Sanctuary (6 km

2), Nambor Wildlife

Sanctuary (37 km2) are located in Golaghat and Karbi Anglong districts. These Sanctuaries

are also a part of Kaziranga-Karbi Anglong Elephant Reserve declared on 17-04-2003 within

an area 3270 km2. However the, Khoraghat Block is not located within 10 km of these

sanctuaries and Kaziranga National Park. No other ecological sensitive area is located within

10 km of the Block boundary (Figure 3.15).

Elephant Habitat

The forest of Golaghat and adjacent district of Karbi-Anglong, namely Diphu, Rengma,

Dayang, Nambor North, Nambor South, Upper Doigurung and Lower Doigurung covering

308.89 km2

(excluding Kaziranga National park) is a key landscape for elephant habitat.

The Golaghat district of Assam was once famous for its thick forest cover and also as a prime

habitat of the endangered Asian elephant (Choudhury, 1999). However, the loss of primary

elephant habitats and subsequent encroachments and alteration of forest land causes decline

of elephant population from more than 500 (excluding Kaziranga National Park) in 1973 to

about 160-190 at present.

Out of 1037.94 km2

hectare of forest areas in 1872 (excluding Kaziranga National Park)

almost 85% are encroached and deforested to date. The Khoraghat Extension ML Block is

located within the Dayang R. F, Rengma R. F and Nambor South R. F. However, entire forest

land in the Block was deforested and encroached, land use also changed from forest to

agriculture and settlement and village infrastructure.

The elephant population in the Golaghat district is now recorded at Deopahar area, Bijuli

Reserve forest area and Nambor Reserve Forest area (Source: Multi-dimensional Mitigation

Initiatives to Human-Elephant Conflicts in Golaghat and adjoining area of Karbi-Anglong District, Assam,

Aaranyak, 2007). In the recent time there is no record of elephant population the Block. The

elephant population map also shows that the Khoraghat Extension ML Block is

approximately 20 km away from recorded Nambor Reserve Forest area. The consultations

with local villagers also confirm that, any straying of elephant is not noticed by the villagers.



Consultation with villagers during field visit

During the field visit extensive consultations were conducted with the villagers of Haldhibari,

Gholapani, Bidyapur, Lakhinagar, Lachit Gaon etc. The discussion revealed that the entire

land within the villages were included under the Rengma Reserved Forest. During British

period the R.F. areas were deforested and settlements and agricultural lands were developed.

The villagers are given land rights from the forest department for undertaking cultivation and

development of settlements. Discussion with villagers revealed wild animals are generally not

spotted in the area. Large mammals like elephants and leopard were also not reported from

the area for a long time.

Consultation with Forest Department Officials of Golaghat

Discussion with Forest official of Golaghat Divisional Forest Office revealed that the entire

area of the Block is under Dayang R. F, Rengma R. F and Nambor South R. F. The Forest

Official reported that the Forest Working Plan for the Division is being prepared and detailed

checklist of flora and fauna within the division is not available with the Forest Department.

The officials also reported that ONGC has also taken Forest Clearance for the well sites

KHDF located within the Block and applied for Forest Clearance for KHDE site.



FIGURE 3-15: ECOLOGICAL SENSITIVITY MAP



FIGURE 3-16: SHOWING THREE HERDS OF ELEPHANT IN GOLAGHAT DISTRICT AND THE BLOCK



Elephant Corridor

There is no established elephant corridor within the Khoraghat Extension ML Block. The

established elephant corridors in the Golaghat and its adjacent Karbi Anglong district has

been described below [Source: Right of Passage: Elephant Corridor of India; WTI, 2004]

and is presented in Figure 3.15.

Kalapahar-Daigurung: This corridor lies between the Kalapahar Unclassified State Forest

(Nambor West block, East Karbi Anglong Division) with Daigurung part of the Daigurung-

Nambor Wildlife Sanctuary (Nambor North block, Golaghat Division). The length and width

of the corridor is 2.0km and 2.0 km respectively. The frequency of usage of the corridor by

elephant is regular used throughout the year. The distance of the corridor from the block

boundary is approximately 30 km.

Aaraynak also prepared a elephant habitat and corridor map for central Golaghat district,

which shows that the elephant movement is restricted in from Kaziranga National Park to

Deopahar area, Bijuli Reserve forest area and Nambor Reserve Forest area. This corridor and

elephant habitat is 30 km from the block boundary.

FIGURE 3-17: ELEPHANT CORRIDORS OF GOLAGHAT DISTRICT

(Source: Aaranyak)



Primate Habitat

The tropical wet evergreen forests of the area provide an ideal habitat for primate species.

The predominant land use in the Block is agriculture land, this is followed by human

settlements with some village woodlot, road. This type of environmental settings is not likely

to provide habitat for primates. The Wildlife Sanctuaries like Nambor-Doigrung WLS,

Garampani WLS, Nambor WLS has the habitat for Hoolock Gibbon and other primates.

Carnivores

The lesser carnivores like, jungle cat (Felis chaus) the large Indian civet (Viverra zibetha),

the small Indian civet (Viverricula indica), the Indian fox (Vulpes bengalensis), the common

mongoose (Herpestes edwardsi), the small Indian mongoose (Herpestes auropunctatus) etc.

was reported in the block and its surrounding areas from the secondary sources.

3.2.8 Faunal Distribution

Mammals: Altogether 230 forms of including species and subspecies have been recorded or

are likely to be found in Assam (Choudhary, 1997). This is one of the highest diversity of

mammals in any of the Indian states i.e. 60% of the total mammalian species found in India.

Mammals within the study area are represented by 10 species of large and smaller mammals.

The checklist of mammals in the study area is given in Annex 3.7. There is no record of large

herbivores and carnivores in the study area. The Asiatic Jackal, Small Indian civet, Small

Indian mongoose, Indian Grey Mongoose are major wildlife in the study area.

Avifauna: About 958 species and subspecies of birds have so far been recorded or likely to

occur in Assam. This is the highest diversity of birds in any of the Indian states. Arunachal

Pradesh comes next with more than 750. Of the 20 orders of birds found in Assam, 12

contain threatened and 11 near threatened species.

Avifauna in the study area represents by the Myna, swifts, drongo, egret, woodpecker, shrike,

barbet etc. A total of 41 species of avi-fauna were recorded from the study area. The detailed

checklist of avi-fauna has been presented in Annex 3.8.

Reptilian Species: At least 187 species have been recorded or likely to be found in Assam.

This includes two species of crocodiles, 21 turtles and tortoise, 46 lizards and 118 snakes

(including three species of monitors). The presence of diverse reptilian species is highest in

any of the Indian states.

Reptilian fauna in the study area represents by the Indian cobra, skink, lizard, gecko etc. A

total of 12 reptilian species were recorded from the study area. The detailed checklist of

reptilian species has been presented in Annex 3.9.

3.2.9 Endemic, Endangered & Threatened Fauna

The Block area forms the habitat of some species which are listed in the Schedule II of the

Indian Wildlife (Protection) Act, 1972 and amendment in 1991. There is no Schedule I



species in the study area, eight species of Schedule II animals were recorded from the study

area. Out of eight Schedule II species, five species belong to mammals and three species

belong to reptiles (Refer Table 3.8).

TABLE 3-7: SCHEDULED ANIMAL SPECIES IN THE STUDY AREA

Wildlife Schedule Sl. No. Scientific Name Common Name

A. Schedule II

A.1 : Mammals

A.1.1 Macaca assamensis Assamese Macaque

A.1.2 Macaca mulatta Rhesus Macaque

A.1.3 Viverricula indica Small Indian Civet

A.1.4 Vulpes bengalensis Indian Fox

A.1.5 Canis aureus Jackal

A.2 : Reptiles

A 2.1 Naja naja Indian cobra

A 2.2 Ptyas mucosus Rat snake

A 2.3 Varanus bengalensis Common Indian monitor

3.2.10 Aquatic Ecosystem

Aquatic Habitat

The Block falls under the watershed of Dhansiri River. The major tributaries and sub-

tributaries of Dhansiri River are Dayang and Rengma that traverses through the Block. There

are also numbers of seasonal rivers and nalas in the Block. All these rivers and nalas form

the aquatic ecosystem. Riparian vegetation was also recorded from the banks of these rivers.

Following aquatic ecological groups has been studied.

Macrophytes

Seasonal wetlands and marshy lands are suitable habitat for aquatic macrophytes. The most

dominant macrophytes are Phragmites karka, Alternantha sessilis, Cyperus rotundus,

Hydrilla verticillata, Lemna natans, Pistia stratiotes. A total of 13 species of aquatic

macrophytes were recorded from these aquatic ecosystems (Annex 3.10).

Fishes

Freshwater fish species in the wetlands of Assam has been well represented. Major fish fauna

of fresh water bodies include catla, rohu, mrigala, bata, punti, titpunti, maurala, chela, boal,

lata, shole, kholse, pancal, tangra, etc. A total of 23 species of fishes were recorded from

these aquatic ecosystems. (Annex 3.11).



Amphibia

Of the 206 amphibian species known from India, only 7 species were recorded from this area

during the study period (Annex 3.12).

Aquatic reptiles: The survey recorded 2 species of aquatic reptiles (Annex 3.13)

Aquatic Birds: The survey results show 9 species of aquatic birds in the study area (Annex

3.14).

Aquatic Mammals: The survey results show one species of aquatic mammal, common otter

(Lutra lutra) from the study area.

Endemic, Threatened & Endangered Species

The wetland areas are the habitat of some threatened species which are listed in the Schedule

II of the Indian Wildlife (Protection) Act. No Schedule I faunal species was recorded in the

aquatic ecosystem in the study area.

3.3 AGRICULTURAL DIVERSITY

The Golaghat district falls under Eastern Himalayan Region (II) agro-climatic zone, where

the annual rainfall is approximately 1990 mm. Predominant soil cover in the district as well

as the Block is Alluvial soil. Net sown area of the district is 143.79 thousand hectare out of

which 36.7% of the net sown area is doubled cropped. Only 11.34% of the net sown area is

under irrigation (tank and open well). Most part of the Block is mono-cropped.

Major crop in the district is paddy. Other important crops are rapeseed/mustard and

horticultural crops like pineapple, banana and lemon. Vegetables like cabbage, tomato, potato

etc. also cultivated in the field during Rabi season. During field visit (April-May) cultivation

of paddy was observed at few places, where the irrigation facility was available. Consultation

with local people revealed that the farmers are cultivating the improved varieties in the field,

the traditional varieties has not been cultivated in the recent times. The proposed KHDE drill

site is located in mono-crop agriculture land where only paddy is cultivated during the

monsoon.

3.4 LIVESTOCK

Livestock like cattle, buffalo, goat sheep, duck, and pig are reared for dairy products, meat,

egg and for agriculture purpose. Majority of cattle are of local variety. Backyard poultry

farms are mostly common in this area.

Livestock use in agriculture field during the off-season as a seasonal grazing field, and their

source of drinking water is surface water (ponds and stream). As the proposed drilling site is

monocropped area and there is no water body, therefore due to the proposed project there will

be no direct impact on domesticated animals. But due to discharge of waste water from the

drilling activity the nearby surface water (stream) may be chemically polluted and affect one

of the drinking water resources for domesticated animals.



3.5 SOCIOECONOMIC ENVIRONMENT

This section discusses the baseline socio-economic environment of the Khoraghat Extension

ML Block in the Golaghat district of Assam with respect to ONGC’s proposed development

drilling operations. The following section discusses the methodology used for the socio-

economic assessment. The subsequent sections discuss the baseline profile of the district and

the villages within the Khoraghat Extension ML Block. The information provided has been

primarily derived from the secondary sources (Census of India and District Statistical

Handbook). In addition primary information was also collected during the discussions at the

villages with the local community members. The informal public discussions have been used

to validate the Census 2001 data. The village-wise secondary data (obtained from Census,

2001 and presented) has been taken into consideration for analyzing the socio-economic

profile in a comparative manner for the Block. As the study area defined for the proposed

project encompasses Golaghat district of Assam, the profiling of the project socioeconomic

environment has focused primarily on the villages located in the aforesaid district.

3.5.1 Methodology

A socio economic assessment of the positive and negative impacts on the people likely to be

directly and indirectly affected by the project was conducted along with other studies during

the EIA study. An assessment was conducted for understanding of the needs, demands,

preferences, capacities and constraints of the people in the vicinity of the project operation. It

was undertaken primarily to enhance the understanding of other relevant factors such as

social organizations and networks, livelihood patterns, social infrastructure etc. and thus

helped prioritise ONGC’s commitment towards the CSR initiatives. Inputs from the social

assessment into the design phase facilitated in:

Tracking potential adverse effects over different time frames and different activities

Reviewing options to eliminate such negative impacts through design changes or

mitigate them through specific social protection or mitigation measures

Reviewing options to extend or enhance benefits for the population in the vicinity of

the project site.

The social assessment was primarily based on the analysis of the secondary data obtained

from the census survey (2001 and district level provisional data of 2011) and stakeholder

consultations. Considering the nature of the project operations and understanding of the

demographic characteristics of the area from the secondary data the following tools was used

for the gathering information and validating the secondary data to carry out the assessment.

Stakeholders Identification

At the beginning of the EIA process, the SENES team conducted a preliminary identification

of probable stakeholders. An inventory of actual / potential stakeholders, including local

groups and individuals, local institutions like the Panchayat which may be directly or



indirectly affected by the project or with interest in the development activities of the region.

This inventory was arrived through discussions with ONGC personnel and members of the

local community. The local communities which would primarily be affected were identified

based on the location of the tentative developmental drilling operations as proposed by

ONGC. The villages were selected within the Block of the proposed well location

considering the fact that there might be potential impacts on the socio-economic-cultural and

environment of the local communities residing in these villages. For further assessment of

socioeconomic issues and impacts on different stakeholders, detailed consultations with the

community were planned. The discussions focused on the issues of population/demography,

education profile, medical facilities and amenities like drinking water, transport and

communication and also on primary and secondary occupation of the villagers.

Consultations

Consultations with key stakeholders are a continuous process that was carried all through the

EIA process. The stakeholder analysis was followed by discussions with some of the key

stakeholders to identify their dependence on the affected or shared resources, the extent of

impact on them and measure, which will be undertaken to mitigate these impacts.

Issues like land and resource damage, social disturbance, severance and increased congestion,

noise and air pollution, employment opportunities, need for development of basic

infrastructure, safe drinking water, sanitation facilities in the surrounding villages were

discussed during the consultations so that they can be adequately addressed through the

environment management plans. The consultations also helped in developing preliminary

understanding of the requirement of social development initiatives, which are required in the

project village and may be undertaken as part of the ONGC’s CSR activity.

3.5.2 General Socioeconomic Profile

The Khoraghat Extension ML Block study area falls in the Golaghat district of Assam.

Assam accounts for nearly 2.57% of the country’s population as per the Provisional

Population Totals of Census 2011. Out of the total population, 87% is still rural. In fact

Assam is the most populous state in the North-Eastern region and the provisional figures of

Census 2011 shows an increase in the population density from 340 in 2001 to 397. The 2001

Census represents the sex ratio of Assam as 935 females per 1,000 males. The provisional

figure of Census 2011 shows an improvement in the sex ratio which is presently 954 females

per 1000 males. The Scheduled caste and Scheduled tribe population were 1.83 million

(6.86%) and 3.31 million (12.41 %) respectively (Census 2001). As per Census 2001, Assam

had a total of 4914823 households and the average household size was 5.4 persons per

household. The gross decadal migrants as a percentage of total urban population in 2001 were

7.12. While the gross decadal inter-state migration was insignificant, the gross decadal intra-



state migration of males and females as a percentage of total male and female urban

population in 2001 was 5.75 and 6.22 respectively (Mitra 2008)4. According to a study by

Nath, 20125, there has been undocumented migration in Assam especially in the districts

bordering Bangladesh. The reduction in the migration figures during the last decade points is

mainly due Assam Accord where the Assam state government along with the Government of

India had played an important role in checking the immigration from the bordering country.

The Golaghat district of Assam comprises of 8 administrative blocks. There are 12 nos.

police stations and 6 outposts, 102 Gram Panchayats in the district. The geographical area of

Golaghat district is 3502 sq. km. The total population of the district as per 2001 census is

946,279 which has increased to 1066888 (provisional figures of Census 2011) indicating a

decadal growth of 12.75%. The present decadal growth rate is lower than that of the previous

decadal rate of 14.27%. Population density of Golaghat district for 2011 is 305

individuals/sq. km. which increased from 270 individuals /sq. km. in 2001. The sex ratio has

improved from 930 (Census 2001) to 964 (provisional figures 2011). Average literacy rate of

Golaghat in 2011 were 77.43 compared to 69.38 of 2001. If things are looked out at gender

wise, male and female literacy were 83.56 and 71.09 respectively. For 2001 census, same

figures stood at 77.14 and 60.99 in Golaghat District. Total literate in Golaghat District were

721,764 of which male and female were 396,475 and 325,289 respectively.

3.5.3 Demographic Profile

The study area for socio economic profiling was defined within block and surrounding areas

based on the proposed location of development wells and its proximity to the village and

professional judgment. Of the study area defined, the baseline study focuses on thirty three

villages within the block. All the villages fall within Golaghat district. Majority of the

selected villages (29) lies within Sorupathar sub-district, and rest of the villages (4) lies in

Golaghat sub-district. The list of villages has been provided in the Table 3.9 below.

4 Mitra A., et. al (2008), Rural to Urban Migration: A District Level Analysis for India; IDE Discussion Paper.

No. 137. 2008.3; available at http://hdl.handle.net/2344/729

5 Nath B.K., et.al. (2012), Undocumented Migration in the state of Assam in Northeast India estimates since

1971 to 2001, Asian Journal of Applied Sciences, Vol. 5 Issue 3, pp. 164-173.



TABLE 3-8: LIST OF THE STUDY AREA VILLAGES IN THE BLOCK

District Sub-district/Tehsil Villages

Golaghat Golaghat Majgaon, Santipur No.2, Goroibil, Majgaon

Sorupathar Bil Gaon, Pan Jan, Barijan, Kathonipur, Madhupur No.1,

Madhupur No.2, Kamalpur,, Ranipukhuri, Chetonapur,

Lakhinagar No.1, Lakhinagar No.2, Bidyapur, Janakpur,

Bordondi No.2,, Goroibil, Dhonpur No.2, Lotapur, Haldhibari,

Jordolong No.1, Lachit Gaon No.2, Lachit Gaon No.1,Santipur

No.2, Majgaon, Chetiagaon No.1, Chetiagaon No.2, Jordolong

No.1, Ranipukhuri, Majgaon, Santipur No.2

The study area for socio economic assessment was defined within the Block around the 2

development wells and is based primarily on reconnaissance surveys, census data

information, toposheet maps, understanding of the project and professional judgment.

The demographic profile in terms of total population, household size, sex-ratio of the selected

villages in the block has been summarized in the sections below, while the detailed

demographic profile of the study area villages has been provided in Annex 3.15-3.17.

However, the village level demography, literacy, work class and socioeconomic data of the

2011 census is yet to be available so the sections below have been interpreted from the old

data of 2001 Census.

Population and Household Size

Bidyapur (1555) was having the highest population among the study area villages followed

by Chetiagaon No.1 (1390) and Madhupur No.2 (1335). The lowest populations were

recorded for Bil Gaon (40). All of the above mentioned villages lie in Sorupathar sub-district.

The household size of the study area villages generally ranged within 4.42 to 6.67 with an

average household size of 5.64.

Sex Ratio

The average sex ratio of 944 recorded for the study area villages and is higher than the state

averages of Assam (935).The highest sex ratio is recorded for Barijan and Jordolong No.1

both having sex ratio of 1130 followed by Majgaon (1068) village. Of all the villages within

the study area, 63.63% of the villages have a sex-ratio of more than 900 and the lowest sex-

ratio was been recorded at Madhupur No.1 (768).

Scheduled Caste (SC) & Scheduled Tribes (ST)

The overall demographic data of study area villages shows only 14.65% of the population to

be under ST category whereas 0.02% population belongs to scheduled caste category. The

highest percentage of schedule tribe population was observed for Majgaon (99.83%) whereas

the highest population of schedule caste population was observed for Santipur No.2 (0.99%).



Education & Literacy

The study of the education and literacy profile in the region is relevant in order to have an

understanding whether the proposed project can utilize skilled human resources available

within the area.

Average literacy rate of Golaghat in 2011 were 77.43 compared to 69.38 of 2001. As of 2011

the literacy rate of Golaghat is higher than literacy rate of Assam (72.19%) The average

literacy rate of the study area villages observed as 47.82% which is well below the state

literacy rate (72.19%). The highest literacy rate was observed in Majgaon (74.68%) and the

lowest in Madhupur No.2 (14.31%). Average male and female literacy rate in the study area

was recorded at 56.06% and 39.05% which were much lower than the Golaghat district

average of 77.14 % and 60.99% respectively as well as state average of 75.23 % and 51.85%

respectively.

Economic Activity & Livelihood Pattern

The relevance of economic activity and livelihood pattern is important in the context of the

study since depending on the existing situation one can predict the impact of the project

activity on the economy of the region.

The total working population in the study area villages varied from 15.60% to 69.77%. Of the

total workforce, Majgaon village revealed the highest percentage of workforce with 69.77%

workers while Chetiagaon No.2 revealed the lowest workforce percentage (15.60%).

Major portion (74%) of the population in the study area villages is dependent on cultivation

as possible source of livelihood. The study area mainly comprises of mono-cropped land with

paddy being the major agricultural produce. The “Agriculture Labour” category contribute

next highest workforce category constituting about 19.11% of the study area population.

3.5.4 Socioeconomic Infrastructure

Medical Facilities

In Golaghat district there is 1 Civil hospital 1 sub divisional hospitals, 38 Primary Health

Centers, 1 First Referral Unit, 5 Community Health Center and 144 sub-centers. In the

villages located within the Block primary health centres are present. The nearest Block

Primary Health Centre is at Sorupathar.

Educational Facilities

The study area possesses necessary educational infrastructure to cater to the educational

needs of the population. There are 864 primary schools in Golaghat. The educational

facilities of Golaghat district is provided below;



TABLE 3-9: EDUCATIONAL FACILITIES OF GOLAGHAT DISTRICT

Educational Institution Numbers

Degree Collages 9

Engineering Colleges 1

Technical Institution/Industrial School/Training School 1

Higher Secondary School 23

High School 172

Medium/Senior Basic School 194

Primary/Junior Basic School 864

Source: www.golaghat.gov.in

In almost all the villages of the study area in Golaghat district there exists educational

facilities in the form of primary schools. Haldhibari village also have Secondary School.

However, there is no training/industrial school within 10 kms from the villages.

Drinking Water facilities

The 2011 District Handbook of Assam reveals that drinking water facility exits in the

premises of 46.1 % and close to 28.6 % of 224853 households in the form of tubewell and

dug wells in Golaghat District.

Transport & Communication

The National Highway-39, PWD roads connecting Sarupathar, Barpathar, Uriamghat road are

the major way of transportation for the local people.

Power Supply

Electricity is available in 36.6% of households in the Golaghat district. Reconnaissance

survey revealed that electricity connection is present in almost all the villages within the

Block through a stable 220V electricity supply adequate for domestic, agricultural and other

purposes.

Primary socio-economic study

In addition to the collection and collation of secondary socio-economic data from census

surveys primary level socio-economic information was obtained through stakeholder

consultations and group discussions with village people. The summary findings of the

consultations carried out have been discussed below:

Majority of the people in the area are cultivators and paddy is the major agricultural

produce.

Majority of the houses in the rural and urban areas have electrical connections.

However frequent power failures were reported by the locals during the consultation.



Water requirement is catered through household dug well facility in the village areas.

It was reported during consultations that majority of the parents send their children to

the primary school. Almost every village has a primary school; however, percentage

of students pursuing higher education is comparatively less.

The medical facilities in the area are also not satisfactory. During the public

consultations the household members expressed their concern about the health

facilities. According to them although there exists primary health centers, doctors are

infrequent and moreover since transportation facilities are poor, sometimes they find

it hard to mobilize serious patients to Golaghat.

Photo 3.11: Consultation at Haldhibari Village Photo 3.12: Consultation at Gholapani

Proceedings of Public Meetings within the Block is provided at Annexure 3.18

3.6 CULTURAL AND HISTORICAL SITES

There are no designated archaeological sites within the Khoraghat Extension ML Block. As is

typical of rural India settlements, each village in the block has some cultural sites or sites of

religious significance, like temples, mosques, graveyards etc. Some of them are of

significance for the community. Sometimes their significance is related during specific

seasons/or time of the year.



4 Environmental Impact Assessment

The impact assessment section of the EIA study systematically identifies, characterizes and

evaluates the potential impacts arising out of the project and prioritizes them through a semi-

quantitative system so that they can be effectively addressed by Environment Management

Plans. Potential environmental impacts may arise out of various sequential activities (as

discussed in section 2.6 of this report) to be undertaken as part of proposed project

development drilling operations.

4.1 IMPACT ASSESSMENT METHODOLOGY

An environmental impact identification matrix has been developed to present an overview of

possible interactions between project aspects and components of the environment which may

get affected. The matrix structure takes into account physical, biological and socioeconomic

components of the environment on one axis (X axis) and activities / aspects of the proposed

developmental well drilling project on the other side (Y axis). Aspects (based on phases of

activities like pre-drilling activities, drilling, decommissioning and potential accidental

events) and impacts on environmental components that have been taken into consideration

were in line with standard environment management system terminology. Environmental and

socioeconomic components were identified based on reviewing of applicable legislation and

baseline environment, site reconnaissance visits, discussions with stakeholders and SENES’

professional judgment.

Potential environmental and socio-economic impacts that may result from any of the

identified project aspects has been identified in a matrix based on activity-component

interaction and has subsequently been used to develop an impact evaluation matrix that list

evaluation scores based on significance criteria delineated in section 4.1.2.

4.1.1 Impact Criteria and Ranking

Once all project environmental aspects were comprehensively identified for the different

activities of the project, the level of impact that may result from each of the activity-

component interactions has been assessed based on subjective criteria.

For this, three key elements have been taken into consideration based on standard

environmental assessment methodologies:

Severity of Impact Degree of damage that may be caused to the environmental

components concerned;

Extent of Impact : Geographical spread of impact around project location and

corridors of activities; and

Duration of Impact: Time for which impact lasts taking project lifecycle into account.

These elements have been ranked in three levels viz. 1 (low), 2 (moderate) and 3 (high) based

on the following criteria provided in Table 4.1 below:



TABLE 4-1: IMPACT PREDICTION CRITERIA

Impact

Elements Criteria Ranking

Severity Regional impact resulting in long term and/ or medium damage to

the natural environment.

Major impact on community and occupational health (e.g. serious

injury, loss of life) on account of accidental events viz. well blow-

outs and related operational activities.

Adverse national media attention.

3

Local scale impact resulting in short term change and / or damage to

the natural environment.

Temporary loss of land, livelihood source of affected communities

Local scale impact on terrestrial habitat, endangered species,

drainage pattern and community resources.

Moderate impact on occupation and community health & well being

(e.g. noise, light, odour, dust, injuries to individuals)

Complaints from the public, authorities and possible local media

attention.

2

Limited local scale impact causing temporary loss of some species

etc

Limited impact on human health and well-being (e.g. occasional

dust, odour, light, and traffic noise).

Public Perception/Concern

1

Extent Regional scale impact and including impacts to physical, biological

and socio-economic environment of the Block

3

Largely local level impact limited to immediate vicinity of the

developmental well site

2

Impact not discernible on a local scale 1

Duration The impact is likely to occur during the entire project life cycle and

beyond.

3

The impact is likely to occur in some phases of project life under

normal operating conditions.

2

The impact is very unlikely to occur at any time during project life

cycle but may occur in exceptional circumstances.

1

A positive or beneficial impact that may result from this project has not been ranked and has

been depicted in the form of ++.

4.1.2 Impact Significance

The significance of impact has been adjudged based on a multiplicative factor of three

element rankings. The Table 4.2 (below) depicts impact significance in a scale of LOW-

MEDIUM-HIGH and will be used for delineation of preventive actions, if any, and

management plans for mitigation of impacts.



Impact significance has been determined taking into account measures which have been

factored in the design and planning phase of the project. Legal issues have been taken into

account, wherever appropriate in the criterion sets, to aid in ONGC’s effort to comply with

all relevant legislation and project HSE requirements. Additionally, the results of

quantitative impact prediction exercise, wherever undertaken, have also been fed into the

process.

TABLE 4-2: CRITERIA BASED SIGNIFICANCE OF IMPACTS

Severity of Impact (A) Extent of Impact

(B)

Duration of Impact

(C)

Impact Significance

(A X B X C)

1 1 1 1

Low

1 1 2 2

1 2 1 2

1 1 2 2

2 1 2 4

1 2 2 4

3 1 2 6

Medium

1 3 2 6

2 2 2 8

1 3 3 9

3 1 3 9

3 3 1 9

3 2 2 12

2 3 2 12

2 2 3 12

3 3 2 18

High 3 2 3 18

2 3 3 18

3 3 3 27

- Beneficial Impact - ++

To assist in determining and presenting significance of an impact, an impact evaluation

matrix (Table 4.3) has been developed based on the one developed for the impact

identification exercise. In case an environmental component to be impacted by more than one

project activity, higher impact significance ranking has been taken as the significance ranking

for subject receptor. Impacts that have been determined to be having high significance

ranking of “>18” are considered significant and hence require examination in terms of

preventive actions and/or additional mitigation to reduce level of the potential impact.

Recommended additional mitigation measures and management plans are presented in

Chapter 6. A second evaluation matrix presents significance of impacts after considering

that proposed mitigation measures will be implemented (Table 4.6).

The identified impacts are further discussed in detail in the following section with discussion

focusing on impacts of higher significance. This is followed by a point wise outline of

mitigation measures recommended.



TABLE 4-3: IMPACT IDENTIFICATION MATRIX

Environment

∕

Activity

Physical Environment Biological Environment Socioeconomic Environment

Aes

thet

ics

& V

isu

als

Air

Qu

alit

y

No

ise

Qu

alit

y

Tra

nsp

ort

& T

raff

ic

Lan

d U

se

So

il Q

ual

ity

Lo

cal

Dra

inag

e &

Ph

ysi

og

raph

y

Su

rfac

e W

ater

Res

ou

rces

Su

rfac

e w

ater

qu

alit

y

Gro

und

wat

er

reso

urc

es

Gro

und

wat

er q

ual

ity

Flo

ra &

Flo

ral

Hab

itat

Wil

dli

fe H

abit

at

Fau

na

Th

reat

ened

& E

nd

ang

ered

sp

ecie

s

Mig

rato

ry c

orr

ido

r &

ro

ute

Aq

uat

ic H

abit

at

Aq

uat

ic F

lora

& F

aun

a

Lo

ss o

f L

ivel

iho

od

Co

nfl

ict

on

Jo

b o

pp

ort

un

ity

Dis

rupti

on

of

Infr

astr

uct

ure

Co

mm

on

Pro

per

ty R

eso

urc

es

Du

st &

No

ise

Dis

com

fort

Lo

ss o

f A

gri

cult

ura

l P

roduct

ivit

y

Infl

ux

of

Po

pula

tio

n

Cu

ltura

l &

Her

itag

e S

ite

Job

& E

con

om

ic O

pp

ort

un

ity

Occ

up

atio

nal

Hea

lth

& S

afet

y

Co

mm

un

ity

Hea

lth

& S

afet

y

Pre-Drilling Activities

Site selection and land acquisition

X

X

X

Site clearance and top soil removal X X X

X

X X X

X X

X X

Well site& access road construction X X X X

X

X

X X X

Sourcing & transportation of borrow material etc X X X X

X X

X X

X X

X

X X X

Storage and handling of construction debris X X X

X

Transportation of drilling rig and ancillaries

X X X

X

X

X

X X

Operation DG set

X X

X X X

Workforce engagement & accommodation at construction site

X

X

X

X

X

Consumption of water for construction & domestic use for labourer

X

X

Generation of domestic solid waste & disposal X

X

X X

X X

X Generation of waste water & discharge from construction activity &

labour camp

X X

X

Surface run-off from construction site

X

X X

X X

X

Developmental Well Drilling & Testing

Physical Presence at drill site X

X X X

Operation of DG sets and machinery

X X

X X X X

X X

Operation of drilling rig

X

X

X X X X

X

X

Storage and disposal of drill cuttings and mud X

X

X X

Generation of process waste water & discharge

X X

X X

Surface run-off from drill site

X

X

X X

Generation of domestic waste water & discharge

X

X X

X X

Generation of Municipal waste & disposal X

X

X X

Workforce engagement & accommodation at drill site

X

X

X

X

X

Flaring during production testing and process upset

X X

X X X X X

X X

Accidental events - blow out

X

X

X X X X X X X X X

X X

Accidental events-spillage of chemical & oil

X

X X

X X

Decommissioning and Reinstatement

Dismantling of rig and associated facilities

X X

X X


X X X

X

Removal of well site construction materials & disposal

X X

X

Site Restoration

X

X

+



4.2 IMPACT ASSESSMENT

This section discusses the impacts of the project activities (development drilling) on the

environmental receptors that stand to get affected adversely by the project. It discusses

probable impacts during various phases of the project lifecycle on the environmental and

socioeconomic components. Rankings for every activity – component interaction is based on

the criterion set earlier and resulting environmental significance with necessary justification

that has been recorded below for every set of impacts and the same has been represented in

evaluation matrices. In broader context, it is however important to remember that operations

related to development well drilling, testing and completion activities also include positive

socioeconomic impacts in terms of increase in local business opportunities and on a larger

perspective, by providing potential energy security at a national level.

4.2.1 Visual Impacts & Aesthetics

Khoraghat Extension ML Block is an operating oil and gas field, which has number of

producing wells, GGS etc. Visual impacts during proposed drilling operations is anticipated

from site clearance and well site preparation, vehicles involved in transportation of raw

materials and personnel, material stockpiles and physical presence and operation of drilling

rig and associated facilities.

During drilling site preparation nearly 3.38 ha land is to be cleared for construction of drill

site. Vegetation clearance will not be required for drill site construction as the site KHDE

does not have any trees and KHDF is located within existing GGS-2 of Khoraghat. Again

during site construction activity, dust will be generated from transport of construction

material, machinery and personnel, haphazard dumping of construction waste, domestic

waste from labour camp may cause visual and aesthetic impacts. Such impacts are likely to

be particularly experienced by communities residing in villages (particularly in Haldhibari)

located in the vicinity of KHDE well. As. KHDF will be located within the facility boundary

of GGS-2 visual impacts due to the well alone in unlikely.

Visual impact due to the operation of drilling rig and presence of base camp is not considered

significant given the temporary nature of drilling activities (about 45-60 days) provided the

well is not indicative of any commercial hydrocarbon reserve. Also with drilling waste and

process waste water likely to be temporary stored in impervious pits no visual impact to this

regard is envisaged. Some visual impacts are also envisaged from light generated from

emergency flaring events. However such activity is likely to be of intermittent in nature, to

occur only during process upset and production testing. Reinstatement of well site not

indicative of any commercially exploitable hydrocarbon reserve is also likely to positively

contribute to the site visual aesthetic.

Severity of Impact 1 Extent of Impact 2 Duration of Impact 2

Impact Significance = 4 i.e. Low



Mitigation Measures

All the construction activity will be restricted within the designated site

Dust nuisance from construction site will be suppressed through periodical water

spraying at disturbance area;

On completion of work all temporary structures, surplus materials and wastes will be

completely removed;

Construction wastes and municipal solid waste temporarily stored at the sites will be

transported to the designated disposal site/facility at regular intervals;

After decommissioning of rig and associated facilities, drill sites will be restored –

drill platform will be removed, pits & garland drains will be filled up, construction

material will be removed & disposed;

Site will be rehabilitated through laying of top soil.

4.2.2 Impacts on Air Quality

Operation of vehicles and construction machinery

Exhaust emission from operation of construction machinery is likely to contribute to air

pollutant load (primarily particulate matter, NO2, SO2 etc.) in the ambient air near well sites.

However, considering localized nature of impacts, temporary nature of construction and

necessary mitigation measures likely to be adopted by ONGC (viz. water spraying at site and

approach roads, using vehicles and machineries with valid pollution control certificate etc.)

the impact is considered to be of low significance. The mitigation measures for controlling air

pollution from operation of vehicles and construction machinery have been described at the

end of this sub-section.



Construction material transport, storage and handling

During construction phase it is estimated that about 500 m3 of borrow material and 1000 m

3

of aggregates will be required per well site location for road construction/strengthening and

site preparatory activities. Fugitive emission is therefore anticipated from transportation,

storage and handling of borrow materials by contractor personnel. However, generation of

such fugitive dust is likely to be governed by micro-meteorological conditions (wind speed

and direction) and the transportation route condition. Considering the drilling activity will be

carried out in dry season and majority of internal roads are kutcha or degraded in condition

such impacts are envisaged. However, the construction activity, rig mobilization and

decommissioning activity is a temporary and limited movement of project vehicles (50-60

nos. /well) during drilling phase, adopting specific mitigation measures during construction

and decommissioning phase (viz. water spraying at site and approach roads etc.) the impact



was considered to be of low significance. The mitigation measures for controlling air

pollution from fugitive dust emission have been described at the end of this sub-section.


Impact Significance = 8 i.e. Medium

Operation of Diesel Generator (DG) Sets during Drilling Period

The proposed project will involve the operation of diesel driven 2 X 750 KW generators for

drilling of developmental well. The operation of DG sets will therefore result in the

generation of air pollutants viz. PM, SO2 NOx, and HC thereby affecting the ambient air

quality. The dispersion of these air pollutants may affect the receptors viz. village settlements

located in near vicinity of the well site only under exceptional combination of meteorological

conditions. It has been already mentioned in Section 3.1.2 that PM10, SO2 and NOx

concentrations in ambient air is well within the NAAQS specified limits. Moreover,

considering the temporary nature of drilling phase (approx 45- 60 days), wet and humid

conditions prevalent in the Block region and provision of adequate DG set stack height for

effective dispersion of air pollutants, no significant impact to this regard is envisaged.

Additionally the proponent also plans to adopt and implement necessary mitigation measures

as discussed in the subsequent section to effectively address potential air quality impacts

from DG set operation.

In order to predict the Ground Level Concentrations (GLCs) at various distances from the

source of the above mentioned pollutants, an air modeling exercise has been undertaken and

is discussed in the impact prediction section below. The following input parameters (Refer

Table 4.4) have been considered in the impact prediction modeling undertaken using ISC 3.

TABLE 4-4: INPUT PARAMETERS CONSIDERED FOR MONITORING

Source

Stack

Height

(m)

Stack

Dia(m)

Stack gas

temp (K)

Stack gas

velocity

(m/s)

Emission Rate

(g/sec)

PM NOx SO2 HC

750 KW DG 9 0.30 773 17.0 0.008 1.3 0.003 0.002

Though, ISC3 is a refined model, the model run was carried out based on micro- meteorology

to predict air quality impacts for a average 24 hr period that may be caused by peak power

utilization at the drill site. The model was run considering operation of three 750 KW DG

sets simultaneously and operation of three 750 KW DG and flaring in combination.

Maximum ground level concentrations for the pollutants are provided below (Refer Table

4.5).



TABLE 4-5: PREDICTED GLCS FOR AIR POLLUTANTS

Pollutants

Predicted Maximum GLC (μg/m3)

Incremental

Concentration

Distance from Well

(km) Direction

3 X 750 KW DG sets

NO2 (μg/m3) 25.442 2.213 NW

PM (μg/m3) 0.156 2.213 NW

SOx (μg/m3) 0.024 2.213 NW

HC (μg/m3) 0.0088 2.213 NW

For spatial mapping of pollutants, the GLCs revealing worst case scenarios were

superimposed on land use (5km x 5 km area) abutting KHDF.

The incremental Ground Level Concentration (GLCs) of the pollutants (as discussed above),

do not exhibit any appreciable decrease in air quality. The impact on ambient air quality is

due to operation of DG set is thus considered to be of low significance.





FIGURE 4-1: PREDICTED NOX CONCENTRATION PLOT (2 X 750 KW DG SET)



FIGURE 4-2: PREDICTED PM CONCENTRATION PLOT (2 X 750 KW DG SETS)



FIGURE 4-3: PREDICTED SO2 CONCENTRATION PLOT (2 X 750 KW DG SETS)



Air pollution related impacts on flora and fauna, human communities residing close to the

proposed drill sites have been described at sections 4.2.10 and 4.2.11 respectively.

Occupational health related impacts to workers exposed to high levels of air pollutants have

been described at Section 4.2.12.

The mitigation measures for controlling air pollution from operation of DG sets and emergency

flaring operations have been described below.

FIGURE 4-4: PREDICTED HC CONCENTRATION PLOT (2 X 750 KW DG SETS)



Mitigation measures for controlling impacts on air quality:

All vehicles used for transportation of loose and friable materials will not be loaded

over the freeboard limit and will be covered.

Water spraying will be done on the access roads to control re-entrained dust during

dry season;

Equipment, machinery and vehicles having inbuilt pollution control devices will be

considered as a measure for prevention of air pollution at source

Engines and exhaust systems of all vehicles and equipment used for the project will

be maintained so that exhaust emissions are low and do not breach statutory limits set

for that vehicle/equipment type.

DG set with appropriate stack height will be utilized.

Personnel Protective Equipments (PPEs) like mask will be provided to workers at site.

The detailed plans for controlling impacts to ambient air quality due to the proposed

developmental drilling activities have been provided at Chapter 6.

4.2.3 Impact on Noise Quality

Potential impact on noise quality is anticipated from vehicular movement, operation of

construction machinery during well site preparation and access road strengthening and during

operation of drilling rig.

Operation of construction machinery/equipments

Operation of heavy machinery/equipments and vehicular movement during site preparatory

and road strengthening/construction activities may result in the generation of increased noise

levels. The noise generated from construction machineries generally varies in the range of

88-95 dB (A) as specified in the Table 2.5. The baseline noise level- day time and night time

(Section 3.3) in the villages in proximity to the proposed drill sites were found to be in

compliance to the noise standards for residential areas. The noise related disturbance is likely

to be experienced by communities particularly residing in Haldhibari, Chetanapur, Bidyapur

etc. in proximity of the well construction site and along material transportation routes. The

environmental setting of well sites reveals that settlements are very close (about 50-75 m) to

the proposed well site and site access road. Considering the construction phase activities to be

of temporary nature, limited daily movement of project vehicles (3-4 nos. vehicle for

transportation of personnel and 8-10 nos. for material transport) and adequate mitigation

measures (viz. equipment maintenance etc.) to be implemented by the project proponent,

impact is considered to be of medium significance.






As already mentioned in the previous section that the villages close to the proposed drill sites

revealed baseline noise levels in compliance to the standards prescribed for residential areas.

Operational phase noise impacts are anticipated from operation of drilling rig and ancillary

equipment viz. shale shakers, mud pumps and diesel generators. Studies indicated that noise

generated from operation of drilling rig generally varies in the range of 88-103 dB(A). Other

contributors of high noise level at the developmental well site include shale shakers, mud

pumps and diesel generators. The average equivalent noise levels of drilling rig and ancillary

equipment has been provided in the Table 2.6 for reference.

Further, considering drilling to be a continuous operation, noise generated from aforesaid

equipments has the potential to cause discomfort to the local communities residing in

proximity (within 50 m) of the well site boundary. Occupational health and safety impacts

viz. Noise Induced Hearing Loss (NIHL) is also anticipated on personnel working close to

such noise generating equipment. However, duration of drilling period is short (approx 45-60

days) and necessary noise prevention and control measures viz. use of acoustic barriers,

provisions for proper PPEs, regular preventive maintenance of equipments etc. will be

implemented by ONGC to minimize the impact.

Noise related impacts on flora and fauna, human communities residing close to the proposed

drill sites have been described at sections 4.2.10 and 4.2.11 respectively. Occupational health

related impacts to workers exposed to high noise levels have been described at Section

4.2.12.

Noise Level Prediction

A noise modeling exercise has been undertaken based on standard noise attenuation equations

(refer Annex 4.1) to predict noise levels from drilling rig near sensitive receptors. A noise

attenuation plot has been developed considering natural attenuation by distance with noise

level predictions only expected to help in planning and decision making.

The cumulative noise generated from rig, mud pump, DG and Shale Shaker was calculated to

be 95.0 dB(A). Noise attenuation equations (without any noise barrier) show that the normal

attenuated noise at any receptor points located at a distance of about 100 m and 200 m from

the fence-line of the rig, will be in the range of about 75.0 dB(A) and 69.0 dB(A)

respectively. In the absence of an acoustic barrier, the predicted noise levels were found to

exceed the day time noise standard of i.e. 55 dB (A) leading to discomfort to neighbouring

communities. However, with the introduction of a noise barrier at the fence-line with a height

of 4 m the noise level may be controlled. This control measure will be enough to decrease

noise levels near sensitive receptors at 200m to about 55.98 dB (A). However a detailed noise

modelling exercise to look at option of noise reductions will be conducted at the design stage

to determine the barrier specifications. The noise attenuation plot with and without acoustic

barrier is presented in Figure 4.5 below.



FIGURE 4-5: NOISE ATTENUATION PLOT



Mitigation measures for controlling impacts on noise quality

Typical mitigation measures for controlling noise quality impacts will include the following:

Installation of sufficient engineering control on equipment and machinery (like

mufflers & noise enclosures for DG sets and PC pumps) to reduce noise emission

levels at source, carrying out proper maintenance and subjecting them to rigid noise

and vibration control procedures.

Re-locating noise sources to less sensitive areas to take advantage of distance and

shielding

Providing Personnel Protective Equipments (PPEs) like ear plugs/muffs to workers at

site.

Undertaking preventive maintenance of vehicles and machinery to reduce noise

levels.

The detailed plans to control impacts on noise quality due to the proposed developmental

drilling activities have been provided at Chapter 6.

4.2.4 Potential Impact Transport and Traffic

The drill site access roads (i.e. PWD road, village road) are not located on busy vehicular

route. The traffic survey data shows that 128 nos. (22 nos. heavy vehicles) recorded at

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

10

20

30

40

50

60

70

80

90

10

0

11

0

12

0

13

0

14

0

15

0

16

0

17

0

18

0

19

0

20

0

21

0

22

0

23

0

24

0

25

0

No

ise

Le

vel d

B(A

)

Distance (m)

Predicted Noise Level with & without attenuation

Noise Level of Machinery with Base Noise and without Attenuation

Noise Level of Machinery with Base Noise and with Attenuation



Haldhibari –Uriamghat road and 211 nos. (54 nos. heavy vehicles) vehicles recorded on

Uriamghat-Bidyapur Road.

Movement of heavy vehicles estimated to about 60 truck/trailer load (from Jorhat to the

Block) is anticipated during both site construction and decommissioning phases. During

drilling phase 5-6 medium to small vehicles will be used for transportation of personnel to the

drill sites. Transportation of vehicles during various projects phases particularly during site

construction and decommissioning is likely to cause disturbance to the villages in the access

routes. In the transport route, few schools viz. Haldhibari Secondary School, Haldhibari

Bamchuk Primary School are also located. Disturbance to traffic movement during school

hours is therefore anticipated from additional traffic load during project activity. With respect

to increase in traffic movement the impact is considered to be of medium significance. As,

discussed in Section 3.1.12 the access roads within the Block are already in dilapidated

condition, transportation of heavy vehicles will deteriorate the road condition further and

cause disruption of local infrastructure.



The detailed traffic management plan for the proposed developmental drilling activities has

been provided at Chapter 6.

4.2.5 Potential Impact on Land Use

Approximately 3.38 ha of agricultural land will be required for construction of drill site

KHDE, while KHDF is located within ONGC existing Khoraghat GGS-2 where no additional

land will be required. Both the proposed well sites are located within Rengma Reserve Forest.

ONGC has taken Forest Clearance (FC) for the KHDF site and applied for FC for KHDD and

KHDE to Assam Forest Department.

As discussed earlier, as the land for KHDD and KHDE is currently being used for agriculture

purpose, ONGC will have to take the land in long term lease from the local panchayat. In

long term lease land will be converted from forest land to industrial land. The land for KHDF

is already under ONGC’s possession in long-term lease (10 year) from the land-owner. After

the completion of the lease period the land will be reinstated and converted to agricultural

land before handing over to the panchayat. Additionally with necessary measures to be

adopted by ONGC through provision of adequate compensation against loss of standing crops

and reinstatement of well site in accordance to defined post closure plan and regulatory

requirements the impact is considered to be of medium significance.





Mitigation Measures

Obtain necessary permission for KHDD and KHDE from the Forest Department and

subsequent implementation of permit conditions.

Provide adequate compensation to landowners against loss of standing crops.

4.2.6 Impact on Soil Quality

Potential impact on soil quality is envisaged in the form of increase in soil erosion and loss of

soil fertility resulting from site clearance and top soil stripping for well site preparation

(particularly in KHDF and KHDE) and accidental spillage resulting from storage and

handling of mud chemicals Soil quality impacts so identified have been assessed and

evaluated in the section below.

Site clearance and stripping of top soil

As discussed in the baseline section 3.1.9, the soil of the area abutting the proposed wells is

characterized by fertile alluvial soil thereby contributing to the agricultural productivity of the

region. Stripping of top soil during site preparation of KHDE and KHDD is therefore likely

to affect the soil fertility of the site. It is estimated that about 3375 m3 of top soil will be

removed per well site having an area of 2.25 ha considering 15 cm top soil. However, such

impact is considered to be temporary taking into account the fact the proper reinstatement of

site will be undertaken by the proponent after the development activities. Necessary surface

run-off control measures need to be adopted by the proponent during construction phase to

prevent contamination of abutting agricultural land from discharge of surface run-off

characterized by increased sediment load. Further specific mitigation measures will be

implemented by the proponent to stabilize the top soil to preserve their fertility characteristics

during site restoration. The impact is therefore considered to be of low significance.



Sourcing of borrow material

Site preparatory activities will involve the sourcing of earth-fill from borrow areas. Such sourcing

activity may lead to direct and indirect long-term major adverse impacts on the environment due

to loss of productive top soil if located on agricultural land or virgin forest land. The loss of top

soil may also enhance the soil erosion potential of the area resulting in increased sediment load in

surface run-off. Since most of the construction materials would be available from existing

quarries nearby, relatively few new borrow areas will be required. Considering above

scenario the impact is considered to be of low significance.





Storage and disposal of drill cuttings and drilling mud

It is estimated that nearly about 212-225 m3

of drill cuttings and waste drilling mud is likely

to be generated from each well during developmental drilling operation. Improper storage

and disposal of such process waste on open soil or unlined areas may therefore lead to the

contamination of soil onsite and abutting land if not properly managed. Construction of a

HDPE lined impervious pits of capacity 2 X 140 m3 each for temporary storage of drill

cuttings and drilling mud respectively and their disposal in accordance with S No. 72 C.1.a

Schedule I Standards for Emission or Discharge of Environmental Pollutants from Oil

Drilling and Gas Extraction Industry of CPCB as modified in 2005 will be ensured by

ONGC. Further with the proponent catering to the use of water based mud the drill cuttings

and waste drilling mud generated are likely to be non-hazardous in nature and is not

anticipated to pose any potential threat to the soil environment. The impact is therefore

considered to be of low significance.



Storage and handling of fuel and chemicals

Contamination of soil can result from the project activities if certain operations like storage of

chemicals and fuels, spent oil and lubricants are not managed efficiently. Storage of

chemicals and fuels, spent lubricants on unpaved surfaces also have potential for

contamination of soil. Accidentally, if chemicals, oil and lubricants are spilled, either during

transportation or handling, on open soil may contribute to soil contamination. However,

considering that appropriate spill prevention and control measures (referred below) to be

implemented by the proponent the impact is considered to be of low significance.



Mitigation measures for reducing impacts on soil quality

Restricted project and related activities during monsoon season;

Carrying out adequate restoration of soil after drilling, to the extent possible;

Implementing adequate sediment control measures to prevent discharge of untreated

surface run-off characterized by increased sediment load to abutting agricultural land.

Ensuring proper storage of drill cutting and waste mud in HDPE lined impervious pits

to prevent any potential contamination from spillage.

All chemical and fuel storage areas, process areas will have proper bunds, an oil-

water separator will be provided at the storm water drainage outlet so that

contaminated run-off cannot escape into the neighbouring agricultural lands.



The detailed plans for management of impacts related to soil quality due to the proposed


4.2.7 Impact on Topography & Drainage

Potential impact on drainage and topography viz. alteration of drainage pattern, water logging

etc. are anticipated during well site preparation, widening/strengthening of access roads and

restoration of developmental well facilities. The impact details have been discussed below:

Site preparation and road construction/strengthening

Potential impact on drainage is primarily anticipated in the form of disruption of natural

drainage pattern during site preparation and approach road construction. Since site

preparation involves raising of acquired/leased land to about 1 m from the ground level it

may lead to alteration of onsite micro-drainage pattern leading to potential problems of water

logging in the agricultural land and settlements abutting the drill site. This problem is likely

to be further aggravated due to heavy rainfall experienced by Golaghat district throughout the

year (Refer section 3.1.2).

About 50 m site approach will be constructed for KHDE and KHDD while KHDF already

have an approach road. However, strengthening and widening of existing access roads will be

required for effective transportation of drilling rig and heavy equipments to the well site.

Widening/ new construction of roads could therefore result in the alteration of drainage along

water crossings and may lead to water-logging of adjacent lands and settlements if not

properly managed. However considering the provision of cross drainage structures viz.

culverts etc. at road embankments and stream crossings by the proponent to ensure

uninterrupted drainage flow the impact is considered to be of medium significance.



Well site restoration

Site restoration will be initiated for well site not indicative of any commercially exploitable

hydrocarbon reserves (or after the production phase if the well site is kept for development

drilling). Unplanned restoration may lead to the long term disruption in natural drainage

pattern and water logging in neighbouring agricultural land abutting the site. However,

adequate care will be taken by the proponent to restore the site back to its original condition

based on the originally existing contours and predominant slope to prevent any such adverse

drainage impacts. The impact is considered to be of medium significance with onsite drainage

being dependent on the proper site restoration.





Mitigation measures for reducing the impact on site topography and drainage

Leveling and grading operations will be undertaken with minimal disturbance to the

existing contour, thereby maintaining the general slope of areas abutting the well site;

Disruption/alteration of micro-drainage pattern will be minimized to the extent

possible.

Loss of micro- drainage, if any, is to be compensated through provision of alternate

drainage.

4.2.8 Impact on Surface Water Quality

Impact on surface water quality of natural drainage channels and community water bodies

may arise from discharge of contaminated surface run-off, sewage and process waste water

generated during various phases of the proposed project. As discussed in Section 3.1.8. The

surface water bodies close to the proposed well sites are used for bathing, washing, fishing

and for irrigation purposes. It has been already discussed in Section 3.1.8 that surface water

discharge from the proposed well sites are most likely to reach the Rengma River and also in

Dayang River via. some minor surface water channels.

Surface run-off discharge

As discussed under section 4.2.4, site clearance and stripping of top soil during site

construction will result in an increase in soil erosion potential leading to an increased

sediment load in the surface run-off during monsoon. Also, surface run off from drilling

waste, hazardous waste (waste oil, used oil etc) and chemical storage areas on open soil is

likely to be contaminated leading to the pollution of receiving water bodies viz. natural

drainage channels, ponds etc. This situation is likely to be more pronounced considering

rainfall records of Golaghat district (Refer section 3.1.2). However, taking into account the

provision of onsite drainage system and sediment control measures to be implemented by the

proponent in compliance with the S No. 72 A.1.a Schedule I Standards for Emission or

Discharge of Environmental Pollutants from Oil Drilling and Gas Extraction Industry of

CPCB as modified in 2005, the impact is considered to be of low significance.



Discharge of drilling wash water

It is estimated that nearly about 9 m3/day of drilling wash water is likely to be generated during

drilling operation. The drilling wash water so generated may be characterized by the presence of

oil & grease, barites and heavy metal which on discharge to nearby natural drainage channels

and/or rivers may lead to possible surface water contamination. However considering usage of

water based mud for the proposed project, temporarily storage of drilling waste in an HDPE lined

pit and subsequent treatment to ensure conformance with CPCB Industry Specific

Standards for Oil Drilling & Gas Extraction Industry and guidelines provided by the MoEF under



the Hazardous Wastes (Management, Handling & Transboundary Movement) Rules, 2008 the

impact is not considered to be of significance.



Mitigation measures for controlling potential surface water impacts

Following mitigation measures will be implemented for water pollution control:

Proper treatment of all wastewater and produced water discharges will be made to

ensure that they comply with CPCB Discharge Standard of Oil and Gas Industry

Drainage and sediment control systems at the well site will be efficiently designed

Construction activities viz. stripping, excavation etc during monsoon season will be

restricted to the extent possible.

All chemical and fuel storage areas, process areas will have proper bunds so that

contaminated run-off cannot escape into the storm-water drainage system. An oil-

water separator will be provided at the storm water drainage outlet, to prevent

discharge of contaminated run-off.

4.2.9 Impact on Hydrogeology & Ground Water Quality

Potential impacts on groundwater quality could arise as a result of the proposed drilling

activities as a result of the following activities:

Ground water extraction

During the initial stages of boring before successful insertion of casing groundwater may be

released leading to the depletion of the groundwater resource. Taking into account drilling to

be a temporary activity (approx 45-60 days) and release of groundwater prior to first casing and

cementing program (2-3 days) impact on ground water resource is considered to be of low

significance.



Storage of drill cuttings and waste drilling mud

Possibility of contamination of subsurface and unconfined aquifers may exist if the casing

and cementing of the well is not carried out properly leading to infiltration or seeping of

drilling chemicals or mud into porous aquifer region. However with the project proponent

catering to the use of water based mud and storage of drill cuttings and waste drilling mud in

an HDPE lined pit, impact is considered to be of low significance.





Mitigation measures for controlling impacts to groundwater quality

Proper engineering controls will be used for drilling and cementing operations

Water based, non hazardous type of drilling mud will be utilized for drilling operation

Drill cuttings & mud will be stored in HDPE lined pits

4.2.10 Impact on Biological Environment

The potential impacts on ecological habitat of the Block region due to proposed development

drilling operations are discussed below:

Loss of flora and floral habitat

KHDE and KHDD will be located on agricultural land where there is no prominent

vegetation except seasonal crops. Reviewing of ecological conditions of the Block reveals no

flora or floral assemblages that are unique to the site or are listed as protected or threatened

plant species. Taking drilling activity into account, drill site will be restored to near original

condition and its impact on flora and floral habitat is considered to be of low significance. As

KHDF is located within the existing GGS no impact is envisaged from the loss of flora of

floral habitat.



Impact of Fauna & Faunal Habitat

KHDE will be located on agricultural land with no prominent vegetation and KHDF is

located within the existing GGS are not ideal habitats for larger fauna. However, noise

generated from drilling activity, lighting at well site, traffic movement will cause of

disturbance to local fauna. It has been already discussed in the “Biological Environment”

section of Chapter 3 no protected ecological habitats are present within 10 km of the

proposed well sites (nearest Wildlife Sanctuary Nambor Wildlife Sanctuary is located at a

distance of more than 20 km from the Block Boundary) and also Schedule I species are not

reported from the area. Few Schedule II species, few mammals, birds, reptiles and

amphibians are reported from the Block areas that can temporarily relocate to places distantly

located from the wells to minimize the impact (of noise and light) the impact is considered to

be of low significance.





Impact on Endangered/Threatened Flora and Fauna

Noise, vibration and light generated during drilling (operation of the rig) are expected to

cause impact on faunal species. However, no threatened or endangered fauna is reported

within 10 km areas of the well sites, with few reported Schedule II species the impact is

considered to be of low significance



Impact on Migratory Corridor & Route

As discussed in the biological environmental section of the report, the nearest established

elephant corridor (Kalapahar-Daigurung) is located more than 30 km from the well sites and

absence of any other migratory route and corridor in the vicinity of the well sites no impact

on the migratory or corridor is envisaged.

Aquatic Habitat, Aquatic Flora & Fauna

The major rivers viz. Dayang River and Rengma River forms the aquatic ecosystem in the

study area. It has been established in the baseline studies, that existing water quality of the

surface water bodies is favorable to support diverse range of aquatic fauna and flora.

Therefore, in case of any discharge of untreated waste water from development drilling site

may result in the possible contamination of receiving streams and their ecological habitat.

Surface runoff during monsoon from the construction site of the wells has the potential to

contaminate receiving surface water bodies thereby impacting their aquatic ecology. Again,

all such process water to be discharged offsite will be undergoing adequate treatment to

comply with discharge standards specified by regulatory authorities. Adequate treatment

coupled with dilution factor of receiving water bodies will thus significantly contribute in

preventing any deleterious effect on the aquatic ecological habitat.



Detailed plans to mitigate impacts on biological environment due to the proposed


4.2.11 Impact on Socioeconomic Environment

Based on the nature and type of impacts, the assessment has been divided into broad

categories namely (i) Adverse impacts and (ii) Positive impacts.

Adverse Impact

Loss of Livelihood

Approximately, 2.25 ha land will be required for drilling of each KHDD and KHDE well

currently in agricultural land. The agricultural lands are mono-crop land. ONGC will take



this land through private negotiation. In all cases, necessary payments will be made against

purchase and crop compensation to concerned land owners. The proposed project would not

require any displacement of villagers. The impact on livelihood is considered to be of medium

significance. As KHDF will be located on existing GGS land procurement and loss of livelihood

would not take place.



Conflicts on Job Opportunity

Primary survey and public consultation showed that the local people desired to work in the

ONGC. Involvement of outside workers in proposed activity may possibly create conflict

with the local people, as most of the villagers are small scale cultivators, daily labours, small

businessmen. Local people strongly objected to outsiders, and demanded that major

proportion of workers be involved from surrounding villages. As majority of the workers

involved in well site construction, approach road construction and strengthening will be

sourced from the local villages conflicts due to job opportunity will be considered to be of

low significance.


Impact Significance = 4 i.e. low

Disruption on Infrastructure

Main roads within the Block are weathered black top roads and internal village roads are

Kutcha road. Transportation of borrow materials, drilling rig and associated facilities could

deteriorate the road conditions if not properly maintained. The impact in this respect is

considered to be of medium significance



Dust and Noise Discomfort

Both the proposed wells are located in close proximity to settlement. Inhabitants residing

close to access roads will get affected due to noise and dust generated from vehicular

movement during site preparation, setting up of rig and associated facilities,

decommissioning of rig and associated facilities. Again, during drilling operation, inhabitants

residing close to drill sites (particularly at Haldhibari and Chetanapur) will get affected due to

noise and emissions from DG sets and occasional flaring activity. Considering proximity of

human settlement and short term activity with proper mitigation measures, impact will be of

Medium significance.





Ecological Productivity of Agricultural Fields

Ecological productivity of the agricultural land taken up for drilling of KHDE well will affect

during the entire lifecycle of the project. Reinstatement of ecological productivity will be

dependent on successful restoration of soils, their structure, chemistry drainage characteristics

and possibly other physical factors, such as micro-topography. These will provide a basis for

successful recovery of ecological populations, whether allowed to occur naturally or aided by

seeding and cultivation. However, considering necessary mitigation measures like top soil

preservation, process water treatment etc. will be implemented by the proponent. During

various project phases any impact in this regard is considered to be of low significance.



Influx of Population

Influx of population is anticipated in all stages of the project cycle particularly during both

development drilling. The drill site will involve the operation of about 30 onsite workers.

Hence there might be an impact on the local communities due to the sharing of common

resources like space, drinking water, roads etc. Interaction between workers with villagers of

nearby areas might give rise to various issues like conflict of workers with the local

population, nuisance caused by workers due to improper sanitation facilities, etc. However,

taking into account that workforce is likely to be sourced from nearby villages and adequate

sanitation facilities will be provided chances of such conflicts are negligible.



Cultural & Heritage Site

Impact on cultural environment may occur due to site preparation, operation of drilling rig

and also during vehicular movement with respect to the proposed exploration activities.

There are no designated historical or cultural spots within Khoraghat Extension ML Block.

The project will however be adopting following mitigation measures to prevent any adverse

impact to properties/remains of cultural and historical significance of any such remains

accidentally encountered during aforesaid activities.

Prior to commencement of site construction activities, location of cultural important

properties will be communicated to the contractor; and reporting of chance find of any

properties/remains of archeological significance by the contractor to the proponent. Thus any

significant impact due to project activities on cultural environment of the block is unlikely.





Employment opportunities: Project will benefit people living in the neighboring villages by

giving preference to them in relation to direct & indirect employment associated with the

various project activities. Site preparation phase will involve certain number of labourers and

there is a possibility that local people can be engaged for this purpose and hence improve

existing employment scenario of the region. Drilling process will involve a number of skilled

and unskilled workers. However, most jobs will comprise technical involvement. Hence

villagers can possibly be employed only in certain non-technical or casual labor jobs and that

too for a limited duration. It is proposed that first preference be given to people whose land is

acquired and to their relations. Next preference will be given to the poorer people and

subsequently the other villagers.

Detailed plans to mitigate impacts on socio-economic environment due to the proposed


4.2.12 Impact on Occupational Health and Safety

Occupational injuries and ill-health have huge socio-economic implications on individuals,

their families and communities. They also have economic impacts in form of direct and

indirect costs for society as a whole. Major occupational health risks encountered in proposed

drilling activity include noise from drilling activity, operation of heavy vehicles and

machinery, handing of chemicals.

However, the proponent will adopt necessary control measures through implementation of

mitigation measures (viz. safety training to workers, provision of proper PPEs etc.) to prevent

and/or mitigate adverse health related impacts. Hence any possible occupational health

impact from exposure to such fugitive dust is not likely to be of major significance.



Community Health & Safety: Community health and safety of inhabitants residing close to

the drilling site stands to get affected from frequent heavy vehicular movement along village

access roads and due to noise from drilling rig operations. Health and safety impact arising

from technological emergencies viz. well blow outs, explosions will be dealt separately in the

Quantitative Risk Assessment section (Chapter 5). Although the aforesaid activities are

temporary in nature it may not adversely affect community health and safety and hence is

considered to be of medium significance.



Impact Significance = ++ i.e. POSITIVE



TABLE 4-6: IMPACT SIGNIFICANCE MATRIX (WITH MITIGATION)

Environment

Activity

Physical Environment Biological Environment Socioeconomic Environment

Aes

thet

ics

& V

isu

als

Air

Qu

alit

y

No

ise

Qu

alit

y

Tra

nsp

ort

& T

raff

ic

Lan

d U

se

So

il Q

ual

ity

Lo

cal

Dra

inag

e &

Ph

ysi

og

raph

y

Su

rfac

e W

ater

Res

ou

rces

Su

rfac

e w

ater

qu

alit

y

Gro

und

wat

er R

eso

urc

es

Gro

und

wat

er q

ual

ity

Flo

ra &

Flo

ral

Hab

itat

Wil

dli

fe H

abit

at

Fau

na

Th

reat

ened

& E

nd

ang

ered

spec

ies

Mig

rato

ry c

orr

ido

r &

ro

ute

Aq

uat

ic H

abit

at

Aq

uat

ic F

lora

& F

aun

a

Lo

ss o

f L

ivel

iho

od

Co

nfl

ict

on

Jo

b o

pp

ort

un

ity

Dis

rupti

on

of

Infr

astr

uct

ure

Co

mm

on

Pro

per

ty R

eso

urc

es

Du

st &

No

ise

Dis

com

fort

Lo

ss o

f A

gri

cult

ura

l

Pro

du

ctiv

ity

Infl

ux

of

Po

pula

tio

n

Cu

ltura

l &

Her

itag

e S

ite

Job

& E

con

om

ic O

pp

ort

un

ity

Occ

up

atio

nal

Hea

lth

& S

afet

y

Co

mm

un

ity

Hea

lth

& S

afet

y

Pre-Drilling Activities

Site selection and land acquisition

M

M

L

Site clearance and top soil removal L L M

L

L L L

L L

+ L

Well site& access road construction L L M M

M

L

+ L L

Sourcing & transportation of borrow material etc L M M M

M M

L L

L M

M

+ M M

Storage and handling of construction debris L L

L


L M M

L

M

M

M M

Operation DG set

L L

L L L

Workforce engagement & accommodation at construction site

L

L

L

+

L

Consumption of water for construction & domestic use for labourer

L

L

Generation of domestic solid waste & disposal L

L

L L

L L

L Generation of waste water & discharge from construction activity &

labour camp

L

L

L

Surface run-off from construction site

L

L L

L L

L

Development Well Drilling & Testing

Physical Presence at drill site L

L L L

Operation of DG sets and machinery

L M

L L L L

M M


M

L

L L L L

M

M

Storage and disposal of drill cuttings and mud L

M

M M

Generation of process waste water & discharge

M L

L L

Surface run-off from drill site

L

L

L L

Generation of domestic waste water & discharge

L

L L

L L

Generation of Municipal waste & disposal L

L

L L

Workforce engagement & accommodation at drill site

L

L

L

+

M

Flaring during production testing and process upset

L M

M L L L L

M M

Accidental events - blow out

L

M

M M M L L L L L L

M M

Accidental events-spillage of chemical & oil

M

M M

L L

Decommissioning and Reinstatement

Dismantling of rig and associated facilities

L M

M M


L M M

M

Removal of well site construction materials & disposal

L M

M

Site Restoration

+

+

+



QRA as a part of integrated risk management process for the proposed project consists of the

following iterative steps:

Identification of hazards

Setting Acceptance Standards for the defined risks

Evaluation of likelihood and consequences and risks of possible events.

Confirmation of arrangements to mitigate the events and respond to the same on occurrence.

Establishment of performance standards

Establishment of continuous monitoring, review and auditing of arrangements

5 Quantitative Risk Assessment (QRA)

This section on Quantitative Risk Assessment (QRA) aims to provide a systematic analysis of

the major risks that may arise as a result of onshore development drilling activities by ONGC

in Khoraghat Extension ML Block. The QRA process outlines rational evaluations of the

identified risks based on their significance and provides the outline for appropriate preventive

and risk mitigation measures. Results of the QRA provides valuable inputs into the overall

project planning and the decision making process for effectively addressing the identified

risks. This will ensure that the project risks stay below As Low As Reasonably Practicable

(ALARP) levels at all times during project implementation. In addition, the QRA will also

help in assessing risks arising from potential emergency situations like a blow out and

develop a structured Emergency Response Plan (ERP) to restrict damage to personnel,

infrastructure and the environment.

BOX 5.1: QRA – INTEGRATED RISK MANAGEMENT PROCESS

The risk study for the onshore exploration activities has considered all aspects of operation of

the drilling rig and other associated activities during the development phase. Oil spills, loss of

well control / blow-out and process leaks constitute the major potential hazards that may be

associated with the proposed onshore development drilling of hydrocarbons in Khoraghat

Extension ML Block.

The following section describes objectives, methodology of the risk assessment study and

then presents the assessment for each of the potential risk separately. This includes

identification of major hazards, hazard screening and ranking, frequency and consequence

analysis for major hazards. The hazards have subsequently been quantitatively evaluated

through a criteria based risk evaluation matrix. Risk mitigation measures to reduce significant

risks to acceptable levels have also been recommended as a part of the risk assessment study.

5.1 OBJECTIVE OF THE QRA STUDY

The overall objective of this QRA with respect to the proposed project involves identification

and evaluation of major risks, prioritizing risks identified based on their hazard consequences

and formulating suitable risk reduction/mitigation measures in line with the ALARP

principle. Hence in order to ensure effective management of any emergency situations (with



potential individual and societal risks) that may arise during the development drilling

activities, following specific objectives need to be achieved.

Identify potential risk scenarios that may arise out of proposed drilling and other

associated activities like operation of ancillary facilities and equipment’s, mud

chemicals storage and handling etc.

Analyze the possible likelihood and frequency of such risk scenarios by reviewing

historical accident related data for onshore & offshore oil and gas industries.

Predict the consequences of such potential risk scenarios and if consequences are

high, establish the same by through application of quantitative simulations.

Recommend feasible preventive and risk mitigation measures as well as provide

inputs for drawing up of Emergency Management Plan (EMP) for the project.

5.2 RISK ASSESSMENT METHODOLOGY

The risk assessment process is primarily based on likelihood of occurrence of the risks

identified and their possible hazard consequences particularly being evaluated through

hypothetical accident scenarios. With respect to the proposed project, major risks viz. blow

outs, process leaks and fires, non-process fires etc. have been assessed and evaluated through

a risk matrix generated to combine the risk severity and likelihood factor. Risk associated

with the development drilling activities have been determined semi- quantitatively as the

product of likelihood/probability and severity/consequence by using order of magnitude data

(risk ranking = severity/consequence factor X likelihood/probability factor). Significance of

such project related risks was then established through their classification as high, medium,

low, very low depending upon risk ranking.

The risk matrix is a widely accepted as standardized method of quantitative risk assessment

and is preferred over purely quantitative methods, given that its inherent limitations to define

a risk event is certain. Application of this tool has resulted in the prioritization of the potential

risks events for the development drilling operations thus providing the basis for drawing up

risk mitigation measures and leading to formulation of plans for risk and emergency

management. The overall approach is summarized in the Figure 5.1



FIGURE 5-1: RISK ASSESSMENT METHODOLOGY

5.2.1 Hazard Identification

Hazard identification for the purposes of this QRA comprised of a review of the project and

associated activity related information provided by ONGC as part of its Emergency Response

Plan. In addition, guidance provided by knowledge platforms/portals of the upstream oil &

gas industry including OGP, ITOPF and DNV, Norwegian Petroleum Directorate etc. are

used to identify potential hazards that can arise out of proposed project activities.

Taking into account the applicability of different risk aspects in context of the drilling

operations to be undertaken in the Khoraghat Extension ML Block, there are three major

categories of hazards that can be associated with proposed project which has been dealt with

in detail. This includes:

Blowouts leading to pool fires/jet fires and oil spills

Process leaks and fires

Non-process fires / explosions



Well control incident covers a range of events which have the potential of leading to blow-

outs but are generally controlled by necessary technological interventions. Hence, such

incidents are considered of minor consequences and as a result not well documented. Other

possible hazard scenarios like mud chemical spills, falls, etc. has also not been considered for

detailed assessment as preliminary evaluation has indicated that the overall risk that may

arise out of them would be low. In addition, it is understood that, causative factors and

mitigation measures for such events can be adequately taken care of through exiting safety

management procedures and practices of ONGC.

It must also be noted here that many hazards identified are sometimes interrelated with one

hazard often having the ability to trigger off another hazard through a domino effect. For

example, a large oil spill in most instances is caused by another hazardous incident like a

blowout or process leak. This aspect has been considered while drawing up hazard mitigation

measures and such linkages (between hazards) has also been given due importance for

managing hazards and associated risks in a composite manner through ONGC’s Health,

Safety & Environmental Management System (HSEMS) and through the Emergency

Management Plan, if a contingency situation so arises.

5.2.2 Frequency Analysis

Frequency analysis involves estimating the likelihood of each of the failure cases identified

during the hazard identification stage. The analysis of frequencies of occurrences for the key

hazards that has been listed out is important to assess the likelihood of such hazards to

actually unfold during the lifecycle of the project. The frequency analysis approach for the

proposed project is based primarily on historical accident frequency data, event tree analysis

and judgmental evaluation. Major oil and gas industry information sources viz. statistical

data, historical records and global industry experience were considered during the frequency

analysis of the major identified risks6.

For QRA for the proposed project, various accident statistics and published oil industry

databases have been consulted for arriving at probable frequencies of identified hazards.

However, taking into account the absence of representative historical data/statistics with

respect to onshore operations7, relevant offshore accident databases have been considered in

the frequency analysis of identified hazards. The same has been recommended in the “Risk

Assessment Data Directory” published by the International Association of Oil & Gas

Producers (OGP). Key databases/reports referred as part of the QRA study includes

Worldwide Offshore Accident Databank (WOAD), Outer Continental Shelf (OCS) Reports,

6 It is to be noted that the frequency of occurrences are usually obtained by a combination of component

probabilities derived on basis of reliability data and /or statistical analysis of historical data.

7 Although Alberta Energy & Utilities Board (EUB) maintains a database for onshore incidents for the period

1975-1990 the same has not been considered in the context of the present study as the Alberta wells are believed

to be sour with precaution being taken accordingly to minimize the likelihood of release.



Norwegian Petroleum Directorate Directives, Offshore Reliability Data (OREDA)

Handbook, HSE Offshore Incident Database, SINTEF Offshore Blowout Database etc.

Based on the range of probabilities arrived at for different potential hazards that may be

encountered during the proposed drilling activities, following criteria for likelihood rankings

have been drawn up as presented in the Table 5.1.

TABLE 5-1: FREQUENCY CATEGORIES AND CRITERIA

Likelihood Ranking Criteria Ranking

(cases/year) Frequency Class

5 >1.0 Frequent

4 >10-1

to <1.0 Probable

3 >10-3

to <10-1

Occasional/Rare

2 >10-5

to <10-3

Not Likely

1 >10-6

to <10-5

Improbable

5.2.3 Consequence Analysis

In parallel to frequency analysis, hazard prediction / consequence analysis exercise assesses

resulting effects in instances when accidents occur and their likely impact on project

personnel, infrastructure and environment. In relation to the proposed project, estimation of

consequences for each possible event has been based either on accident experience,

consequence modeling or professional judgment, as appropriate.

Given the high risk perception associated with blow outs in context of onshore drilling

operation, a detailed analysis of consequences has been undertaken for blow outs taking into

account physical factors and technological interventions. Consequences of such accidental

events on the physical, biological and socio-economic environment have been studied to

evaluate the potential of the identified risks/hazards. In all, the consequence analysis takes

into account the following aspects:

Nature of impact on environment and community;

Occupational health and safety;

Asset and property damage;

Corporate image

Timeline for restoration of environmental and property damage

Restoration cost for environmental and property damage

The following criterion for consequence rankings (Table 5.2) is drawn up in context of the

possible consequences of risk events that may occur during proposed development drilling

activities:



TABLE 5-2: SEVERITY CATEGORIES AND CRITERIA

Consequence Ranking Criteria Definition

Catastrophic 5 Multiple fatalities/Permanent total disability to more

than 50 persons

Severe violations of national limits for environmental

emission

More than 5 years for natural recovery

Net negative financial impact of >10 crores

Long term impact on ecologically sensitive areas

International media coverage

National stakeholder concern and media coverage

Major 4 Single fatality/permanent total disability to one or more

persons

Major violations of national limits for environmental

emissions

2-5 years for natural recovery

Net negative financial impact of 5 -10 crores

Significant impact on endangered and threatened floral

and faunal species

Loss of corporate image and reputation

Moderate 3 Short term hospitalization & rehabilitation leading to

recovery

Short term violations of national limits for

environmental emissions

1-2 years for natural recovery

Net negative financial impact of 1-5 crores

Short term impact on protected natural habitats

State wide media coverage

Minor 2 Medical treatment injuries

1 year for natural recovery

Net negative financial impact of 0.5 – 1 crore

Temporary environmental impacts which can be

mitigated

Local stakeholder concern and public attention

Insignificant 1 First Aid treatment with no Lost Time Incidents (LTIs)

Natural recovery < 1year

Net negative financial impact of <0.5 crores.

No significant impact on environmental components

No media coverage



5.2.4 Risk Evaluation

Based on ranking of likelihood and frequencies, each identified hazard has been evaluated

based on the likelihood of occurrence and the magnitude of consequences. Significance of

risks is expressed as the product of likelihood and consequence of the risk event, expressed as

follows:

Significance = Likelihood X Consequence

The Table 5.3 below illustrates all possible product results for five likelihood and

consequence categories while the Table 5.4 assigns risk significance criteria in four regions

that identify the limit of risk acceptability. Depending on the position of intersection of a

column with a row in the risk matrix, hazard prone activities have been classified as low,

medium and high thereby qualifying a set of risk reduction / mitigation strategies.

TABLE 5-3: RISK MATRIX

Con

seq

uen

ce →

Likelihood →

Frequent Probable Remote Not Likely Improbable

5 4 3 2 1

Catastrophic 5 25 20 15 10 5

Major 4 20 16 12 8 4

Moderate 3 15 12 9 6 3

Minor 2 10 8 6 4 2

Insignificant 1 5 4 3 2 1

TABLE 5-4: RISK CRITERIA AND ACTION REQUIREMENTS

Risk Significance Criteria Definition & Action Requirements

High (16 - 25) “Risk requires attention” – Project HSE Management need to ensure

that necessary mitigation are adopted to ensure that possible risk remains

within acceptable limits

Medium (10 – 15) “Risk is tolerable” – Project HSE Management needs to adopt necessary

measures to prevent any change/modification of existing risk controls and

ensure implementation of all practicable controls.

Low (5 – 9) “Risk is acceptable” – Project related risks are managed by well-

established controls and routine processes/procedures. Implementation of

additional controls can be considered.

Very Low (1 – 4) “Risk is acceptable” – All risks are managed by well-established

controls and routine processes/procedures. Additional risk controls need

not to be considered



5.3 RISK ASSESSMENT OF IDENTIFIED PROJECT HAZARDS

As already discussed in the previous section, three major categories risk have identified in

relation to proposed development drilling activities. A comprehensive risk assessment study

has been undertaken to assess and evaluate significance of identified risks in terms of severity

of consequences and likelihood of occurrence. Risk assessment study details have been

summarized in the subsequent sections below:

5.3.1 Blow Outs/Loss of Well Control

Blow out is an uncontrolled release of well fluid (primarily hydrocarbons viz. oil and/or gas

and may also include drilling mud, completion fluid, water etc) from a development well.

Blow outs are the result of failure to control a kick and regain pressure control and are

typically caused by equipment failure or human error. The possible blow out cause events

occurring in isolation or in combination have been listed below:

Formation fluid entry into well bore

Loss of containment due to malfunction (viz. wire lining)

Well head damage (e.g. by fires, storms, dropped object etc)

Rig forced off station (e.g. by anchor failure) damaging Blow Out Preventor (BOP) or

wellhead

The most common cause of blow out can be associated with the sudden/unexpected

entry/release of formation fluid into well bore that may arise as a result of the following

events as discussed in the Box 5.2 below.



BOX 5.2: PRIMARY CAUSES OF BLOW OUTS

Shallow gas

In shallow formations there may be pockets of shallow gas. In these instances there is often insufficient

mud density in the well and no BOP is in place. If the hole strikes shallow gas the gas may be released on

the drilling rig very rapidly. Typical geological features which suggest the presence of shallow gas can

then be detected. Historically, striking of shallow gas has been one of the most frequent causes of

blowouts in drilling.

Swabbing

As the drill pipe is pulled upwards during trips out of the hole or upward movement of the drill string, the

pressure in the hole beneath the drill bit is reduced, creating a suction effect. Sufficient drilling mud must

be pumped down-hole to compensate for this effect or well fluids may enter the bore. Swabbing is also a

frequent cause of drilling blowouts.

High formation pressure

Drilling into an unexpected zone of high pressure may allow formation fluids to enter the well before mud

weight can be increased to prevent it.

Insufficient mud weight

The primary method of well control is the use of drilling mud; in correct operation, the hydrostatic

pressure exerted by the mud prevents well fluids from entering the well bore. A high mud weight

provides safety against well fluids in-flows. However, a high mud weight reduces drilling speed,

therefore, mud weight is calculated to establish weight most suitable to safely control anticipated

formation pressures and allows optimum rates of penetration. If the required mud weight is incorrectly

calculated then well fluid may be able to enter the bore.

Lost Circulation

Drilling mud circulation can be lost if mud enters a permeable formation instead of returning to the rig.

This reduces the hydrostatic pressures exerted by the mud throughout the well bore, and may allow well

fluids from another formation to enter the bore.

Gas cut mud

Drilling fluids are denser than well fluids; this density is required to provide the hydrostatic pressure

which prevents well fluids from entering the bore. If well fluids mix with the mud then its density will be

reduced. As mud is circulated back to surface, hydrostatic pressure exerted by the mud column is reduced.

Once gas reaches surface it is released into the atmosphere.

Source: A Guide to Quantitative Risk Assessment for Offshore Installations; John Spouge – DNV Technica

Publication 99/100a

For better understanding, causes of blow outs have been systematically defined in terms of

loss of pressure control (failure of primary barrier), uncontrolled flow of fluid or failure of

secondary barrier (BOP). The blow out incidents resulting from primary and secondary

failures for proposed operations as obtained through comprehensive root cause analysis of the



Gulf Coast (Texas, OCS and US Gulf of Mexico) Blow Outs8 during 1960-1996 have been

presented in the Table 5.5 below.

TABLE 5-5: BLOW OUT CAUSE DISTRIBUTION FOR FAILURES DURING DRILLING OPERATIONS

Sl. No Causal Factors Blow Out Incidents (nos.)

A Primary Barrier

1 Swabbing 77

2 Drilling Break 52

3 Formation breakdown 38

4 Trapped/expanding gas 09

5 Gas cut mud 26

6 Low mud weight 17

7 Wellhead failure 05

8 Cement setting 05

B Secondary Barrier

1 Failure to close BOP 07

2 Failure of BOP after closure 13

3 BOP not in place 10

4 Fracture at casing shoe 03

5 Failure to stab string valve 09

6 Casing leakage 06

Thus, underlying blowout causes as discussed in the above table can be primarily attributed

to swabbing as the primary barrier failure which is indicative of insufficient attention given to

trip margin and controlling pipe movement speed. Also, it is evident from the above table that

lack of proper maintenance, operational failures and absence of BOPs as secondary barrier

contributed to majority of blowout incidents (approx 30 nos.) is recorded.

Blowout Frequency Analysis

Blow out frequency estimates are obtained from a combination of incident experience and

associated exposure in a given area over a given period. For the purpose of calculation of

blow out frequency analysis in context of the present study involving drilling and

development operations, blow out frequencies per well drilled have been considered.

However due to the lack of availability of representative data on onshore blow out incidents

relevant offshore accident database viz. SINTEF Offshore Blowout Database, OGP Risk

Assessment Data Directory (RADD) and Scandpower which have been referred. The blow

8 “Trends extracted from 1200 Gulf Coast blowouts during 1960-1996” – Pal Skalle and A.L.Podio



out frequency per operation as calculated is based on the SINTEF Offshore Blowout

Database for oil and gas extraction industry has been presented in the Figure 5.2 below.

FIGURE 5-2: BLOW OUT FREQUENCIES IN OIL & GAS INDUSTRY

With respect to the proposed project, the blow out occurrence frequency as based on analysis

of historical data9 has been considered to be 7.5 X 10

-3 per well drilled. Based on the given

frequency and information provided by ONGC on the proposed project development drilling

program the blow out frequency is calculated as follows:

No of development wells to be drilled = 3 (A)

Blow out frequency for drilling = 7.5 X 10-3

per well drilled (B)

Frequency of blow out occurrence for the proposed project = (A X B) = 3 X 7.5 X 10-3

= 2.25 X 10-2

per well drilled

Thus, the blow out frequency for the proposed project is calculated at 2.25 X 10-2

per well

drilled i.e. the likelihood of its occurrence is “Occasional/Rare”

9 Analysis of the SINTEF database for the US GoM OCS/North Sea for the period 1980-92 by Scandpower

(1995)



Blowout Ignition Probability

Review of SINTEF database indicates that a rounded ignition probability of 0.3 has been

widely used for the purpose of quantitative risk analysis arising from blow outs. As per this

database generally ignition occurred within first 5 minutes in approximately 40% of the

blowouts leading to either pool and/or jet fire. Blow out leading to flammable gas release has

a greater probability of ignition compared to liquid releases10

(Figure 5.3).

FIGURE 5-3: IGNITION PROBABILITY VS RELEASE RATE

Further on analysis of the ignition trends over the years it is observed that there has been a

decline in ignition probability hence an average ignition probability of 0.1 (Holand) has been

considered for QRA of the proposed development drilling project.

No of development wells to be drilled = 3 (A)

Blow out frequency for development drilling = 7.5 X 10-3

per well drilled (B)

Blow out ignition probability = 0.1 (C)

Probability of Blow out ignition for the proposed project = (A X B X C) = 3 X 7.5 X 10-3

X 0.1

= 2.25 X 10-3

= ~ 0.0015%

Hence based on the aforesaid calculation the probability of ignition of blow out releases of

hydrocarbons for the proposed development drilling project will be about ~0.0015% and can

be considered to be as negligible.

10 Fire and Explosion – Fire Risk Analysis by Daejun Change, Division of Ocean System and Engineering



Blowout Consequence Analysis

Blow out from a hydrocarbon development well may lead to the following possible risk

consequences:

Pool fires and smoke plumes resulting from ignited oil blow outs

Jet fires resulting from ignited gas blow outs

Oil slicks resulting from un-ignited oil pools.

Most crude oils are more than 95 percent carbon and hydrogen, with small amounts of sulfur,

nitrogen, oxygen, and traces of other elements. Crude oils contain lightweight straight-

chained alkanes (e.g., hexane, heptane); cycloalkanes (e.g., cyclyohexane); aromatics (e.g.,

benzene, toluene); cycloalkanes; and heavy aromatic hydrocarbons (e.g., polycyclic aromatic

hydrocarbons [PAHs], asphaltines). Based on the above discussion and also given the

limitation of ALOHA software with respect to risk modeling of crude oil releases, n-heptane

has been considered as the representative substitute of crude oil for ALOHA based risk

modeling for hydrocarbon releases for the proposed development drilling project. For natural

gas releases leading to jet fire, modeling has been based considering methane which has been

identified as the principal constituent (~ 95%) of natural gas.

Pool fire

A pool fire is a turbulent diffusion fire burning above a pool of vaporizing hydrocarbon fuel

where the fuel vapor has negligible initial momentum. The probability of occurrence of pool

fires for oil and gas exploration and development is high due to continuous handling of heavy

hydrocarbons. The evaporation of hydrocarbons from a pool forms a cloud of vapor above

the pool surface which, on ignition, leads to generation of pool fire.

For the purpose of consequence modeling for pool fires resulting from blow outs, following

hypothetical scenarios in terms of hydrocarbon (particularly crude oil) release rates (Table

5.6) have been considered based on DNV Technica’s FLARE program.

TABLE 5-6: POOL FIRE MODELING SCENARIOS

Scenario Release Rate (kg/s) Release Type

Scenario - I 1 Small

Scenario - II 10 Medium

Scenario – III (Worst Case) 50 Large

The release rates as specified for the aforesaid scenarios have been utilized in the computing

the pool fire diameter utilizing the following equation and input parameters:

D = √4Q/πb

Where D = pool diameter (m)

Q = release rate (kg/s)

b = burning rate (kg/m2s)



The mass burning rate for crude oil has been considered to be 0.05 kg/m2s

Based on above equation, the pool fire diameter and the steady study burning areas computed

for various release types have been presented in the Table 5.7 below.

TABLE 5-7: POOL FIRE DIAMETER & STEADY STATE BURNING AREA

Scenario Release Rate

(kg/s) Release Type

Pool fire

diameter (m)

Steady State Burning

Area (m2)

Scenario - I 1 Small 5.05 6.37

Scenario - II 10 Medium 15.96 63.69

Scenario - III 50 Large 35.69 318.47

The risk scenarios viz. pool fire as discussed in above for the proposed project has been

modeled using ALOHA11

and interpreted in terms of Thermal Radiation Level of Concern

(LOC). Predominant local meteorological conditions as specified in the baseline chapter have

been considered in modeling the safety risks/hazards using ALOHA.

Thermal Radiation Level of Concern (LOC) is a threshold level of thermal radiation, usually

the level above which a hazard may exist. For each LOC chosen, ALOHA estimates a threat

zone where the thermal radiation is predicted to exceed that LOC at some time after a release

begins. These zones are displayed on a single Threat Zone plot displayed as red, orange and

yellow with red representing the worst hazard. The threat zone displayed by ALOHA

represent thermal radiation levels and also indicates the effects on people who are exposed to

those thermal radiation levels but are able to seek shelter within one minute. ALOHA uses

three threshold values (measured in kilowatts per square meter) to create the default threat

zones:

Red: 10 kW/ (sq m) -- potentially lethal within 60 sec;

Orange: 5 kW/ (sq m) -- second-degree burns within 60 sec; and

Yellow: 2 kW/ (sq m) -- pain within 60 sec

The impact zone for long duration fires is conveniently described by overlaying the thermal

radiation contours of worst case scenario (50 kg/s of crude oil release) on the land use map of

the each development well site. These risk contour maps will prove to be of assistance to

ONGC to identify villages and other sensitive receptors, which may fall within the potential

threat zone thereby ensuring better preparedness in terms of risk control and mitigation

during planning stage itself. Well site risk contour maps for worst case scenario prepared

based on ALOHA modeling of pool fire risks has been presented in Figure 5.4-5.5 below.

11 ALOHA is a public domain computer code that is part of a system of software that is known as the Computer-Aided

Management of Emergency Operations (CAMEO) that was developed by the United States Environmental Protection

Agency (EPA), through its Chemical Emergency Preparedness and Prevention Office (CEPPO) to plan for and respond to

chemical emergencies



FIGURE 5-4: KHDE WELL SITE - POOL FIRE RISK CONTOUR MAP



FIGURE 5-5: KHDF WELL SITE - POOL FIRE RISK CONTOUR MAP



In case of well site KHDD the pool fire risk contour map would also be similar in nature of

Figures 5.4-5.5.The thermal radiation threshold values (measured in kilowatts per square

meter) defined for crude oil pool fire consequence modeling for various hypothetical

scenarios as discussed in the earlier section is provided in Table 5.8 below:

TABLE 5-8: DISTANCE TO THERMAL RADIATION THRESHOLD LEVELS

Release

Type

Pool fire

diameter (m)

Pool fire area

(m2)

Distance to

10.0 kW/m2

(m)

Distance to 5.0

kW/m2 (m)

Distance to

2.0 kW/m2

(m)

Small 5.05 6.37 11 17 28

Medium 15.96 63.69 37 55 87

Large 35.69 318.47 84 120 187

The worst hazard for release and ignition of crude oil release at a rate of 50kg/s for a thermal

radiation intensity of 10.0 kW/m2 is likely to be experienced to a maximum distance of 84m

from the source with potential lethal effects experienced within 1 min. Interpretation of the

well site risk contour maps reveals that few settlements of Chetanapur village is falling in the

“Red” Threat Zone with respect to the KHDF development well site. Hence additional care

needs to be taken by ONGC to enhance emergency management preparedness the aforesaid

development well sites in accordance to the Disaster Management Plan.

Risk Ranking – Blowout Pool Fire (Worst Case Scenario)

Likelihood ranking 3 Consequence ranking 4

Risk Ranking & Significance = 12 i.e. “Medium”

Ignition of Flammable Gas Release leading to Jet Fire

Jet fires are burning jet of gas or sprays of atomized liquids resulting from gas and

condensate release from high pressure equipment and blow outs. Jet fires may also result in

the release of high pressure liquid containing dissolved gas due to gas flashing off and

turning the liquid into a spray of small droplets. In context of the present study, formation of

jet fires can be attributed by the high pressure release and ignition of natural gas if

encountered during exploration of block hydrocarbon reserves.

Natural gas as recovered from underground deposits primarily contains methane (CH4) as a

flammable component, but it also contains heavier gaseous hydrocarbons such as ethane

(C2H6), propane (C3H8) and butane (C4H10). Other gases such as CO2, nitrogen and hydrogen

sulfide (H2S) are also often present. Methane is typically 70-90 percent, ethane 5-15 percent,

propane and butane, up to 5 percent. Thus, considering higher percentage of methane in

natural gas, the thermo-chemical properties of the same has been utilized in the jet fire blow

out consequence modeling. The following risk scenarios (Table 5.9) have been considered

for nature gas release consequence modeling:



TABLE 5-9: NATURAL GAS RELEASE MODELING SCENARIOS

Scenario Release Rate (kg/s) Release Type

Scenario - I 1 Small

Scenario - II 5 Medium

Scenario – III (Worst Case) 10 Large

As in the case of pool fire, modeling of nature gas releases has also been carried out using

ALOHA. A Flammable Level of Concern approach has been utilized for assessing safety risk

associated with the release of flammable gases (here methane) from well blow outs.

In ALOHA, a flammable Level of Concern (LOC) is a threshold concentration of fuel in the

air above which a flammability hazard may exist. While modeling the release of a flammable

gas that may catch on fire—but which is not currently burning—ALOHA can predict the

flammable area of the vapor cloud so that flammability hazard can be established.

The flammable area is the part of a flammable vapor cloud where the concentration is in the

flammable range, between the Lower and Upper Explosive Limits (LEL and UEL). These

limits are percentages that represent the concentration of the fuel (that is, the chemical vapor)

in the air. If the chemical vapor comes into contact with an ignition source (such as a spark),

it will burn only if its fuel-air concentration is between the LEL and the UEL—because that

portion of the cloud is already pre-mixed to the right mixture of fuel and air for burning to

occur. If the fuel-air concentration is below the LEL, there is not enough fuel in the air to

sustain a fire or an explosion—it is too lean. If the fuel-air concentration is above the UEL,

there is not enough oxygen to sustain a fire or an explosion because there is too much fuel—it

is too rich.

When a flammable vapor cloud is dispersing, the concentration of fuel in the air is not

uniform; there will be areas where the concentration is higher than the average and areas

where the concentration is lower than the average. This is called concentration patchiness.

Because of concentration patchiness, there will be areas (called pockets) where the chemical

is in the flammable range even though the average concentration has fallen below the LEL.

Because of this, ALOHA's default flammable LOCs are each a fraction of the LEL, rather

than the LEL itself. ALOHA uses 60% of the LEL as the default LOC for the red threat

zone, because some experiments have shown that flame pockets can occur in places where

the average concentration is above that level. Another common threat level used by

responders is 10% of the LEL, which is ALOHA's default LOC for the yellow threat

zone. The flammable LOC threat zones for methane release are as follows:

Red : 26,400 ppm = 60% LEL = Flame Pockets

Yellow: 4,400 ppm = 10% LEL

Well site risk contour maps for worst case scenario prepared based on ALOHA modeling of

natural gas releases for flammable vapour cloud has been presented in Figure 5.6-5.7 below.



FIGURE 5-6: KHDE WELL SITE – RISK CONTOUR MAP FOR NATURAL GAS RELEASE



FIGURE 5-7: KHDF WELL SITE – RISK CONTOUR MAP FOR NATURAL GAS RELEASE



In case of well site KHDD the risk contour map for natural gas release would also be similar

in nature of Figures 5.6-5.7.The zone of flammable vapour cloud calculated for hypothetical

natural gas release under risk scenarios discussed in the earlier sections have been presented

in the Table 5.10 below.

TABLE 5-10: ZONE OF FLAMMABLE VAPOUR CLOUD – NATURAL GAS RELEASE SCENARIOS

Release Type Release Rate (kg/s) Red – 60% LEL (m) Yellow -10% LEL (m)

Small 1 53 161

Medium 5 124 325

Large 10 178 419

Hence for a worst case scenario (10kg/s) the flammable vapor cloud zone/flame pockets’

resulting from accidental release of natural gas will be covering a radial zone of 178m from

source with the flammable gas concentration within this zone being 26,400 ppm. This is of

particular significance for both the development wells where community settlements are

observed to fall within this “flame pocket” zone (Refer Figure 5.6 & 5.7) thereby posing

potential community safety risks in event of an ignition.

Risk Ranking – Blowout Natural Gas Release (Worst Case Scenario)



Oil Spill

Crude oil spills resulting from blow out may result in the formation of un-ignited pools of

liquid the spreading of which is governed by physical factors viz. wind speed, sea currents

(for offshore spills), release rates and spilled chemical characteristics viz. density. Near to the

source of a continuous release, the spreading is dominated by gravity and limited by internal

forces with thickness generally varying within 10-20mm. The spill movement is then resisted

by the viscous shear forces which then continue until the spill thickness is about 1.0mm.

Subsequently, surface tension takes over as the dominant spreading mechanism and it

continues until the thickness has reduced to 0.01 – 0.1mm which may take about 7-10 days

for a large spill depending on various factors as discussed earlier.

With respect to the QRA study hypothetical release rates of 1.0kg/s, 5.0 kg/s and 10.0 kg/s

for 1 day, 4days and 7days respectively have been considered as the possible risk scenarios

for modeling the spread of oil spill following a blow-out incident. The diameter of the pool in

the first phase of an unignited continuous release is obtained by the following equation:

D = 2 [g X Q/ρL 2π] t3/4

Where

D = pool diameter (m)



g = acceleration due to gravity (m/s2)

Q = release rate (kg/s)

ρL = liquid density (kg/m3) (crude oil density is 790 kg/ m

3)

t = time since start of release (s)

The pool diameter so calculated for the aforesaid risk scenarios have been presented in the

Table 5.11 below.

TABLE 5-11: POOL DIAMETER FOR OIL SPILL RISK SCENARIOS

Release Type Release Rate (kg/s) Release Time (s) Oil Spill Pool Diameter (m)

Small 1 86400 19.9

Medium 5 259200 226.9

Large 10 432000 665.7

Hence, for a worst case spill scenario involving a crude oil release rate of 10kg/s for a period

of 7 days the pool diameter for an un-ignited continuous release is predicted to be about

665.7 m. The ignition of the oil pool may lead to the formation of pool fires - consequences

of which have been discussed earlier under the risk related to pool fires. Although the un-

ignited pool is not considered to be of major significance, it may gain significance based on

the environmental impacts that may result from it depending on sensitive receptors identified

abutting the proposed project development well sites.

Risk Ranking – Blowout Oil Spills (Worst Case Scenario)



Preventive and Mitigation Measures

Blowouts being events which may be catastrophic to any well operation, it is essential to take

up as much a preventive measures as feasible. This includes:

Necessary active barriers (eg. Well-designed Blowout Preventor) be installed to

control or contain a potential blowout.

Weekly blow out drills be carried out to test reliability of BOP and preparedness of

drilling team.

Close monitoring of drilling activity be done to check for signs of increasing pressure,

like from shallow gas formations.

Installation of hydrocarbon detectors.



Periodic monitoring and preventive maintenance be undertaken for primary and

secondary barriers installed for blow out prevention, including third party inspection

& testing

An appropriate Emergency Response Plan be finalized and implemented by ONGC.

Marking of hazardous zone (500 meters) around the well site and monitoring of

human movements in the zone.

Training and capacity building exercises/programs be carried out for onsite drilling

crew on potential risks associated with development drilling and their possible

mitigation measures.

Installation of mass communication and public address equipment.

Good layout of well site and escape routes.

Additionally, ONGC will be adopting and implementing the following Safe Operating

Procedures (SOPs) developed as part of its Onsite Emergency Response Plan to prevent and

address any blow out risks that may result during drilling and work over activities:

Blow Out Control Equipment

Choke lines and Choke Manifold Installation with Surface BOP

Kill Lines and Kill Manifold Installation with Surface BOP

Control System for Surface BOP stacks

Testing of Blow Out Prevention Equipment

BOP Drills

5.4 DISASTER MANAGEMENT PLAN

5.4.1 Objective

The primary objective of the DMP is to provide a safe, timely, effective and coordinated

response by the onsite Emergency Response Team (ERT), along with the other local and

government agencies/departments to prevent or minimize any major emergencies that may

arise from possible failures/risks viz. blow outs, oil spill, fire & explosion etc. associated with

development drilling.

The main objectives of this plan are:

To minimize the risk for human life, environment and common property resources, by

means of an effective and efficient intervention;

Protection of the environment;

Protection of public safety;



To initiate the early and efficient response throughout the utilization of all available

resources.

5.4.2 Purpose

The purpose of the DMP is to effectively manage and control the emergencies occurring

during project operations. This DMP ensures,

emergency response group is effective & adequate;

clear roles and responsibilities of key personnel & support groups;

availability and adequacy of emergency infrastructure & resources; and

efficient emergency communication

5.4.3 Emergency Classification

Due consideration is given to the severity of potential emergency situation that may arise as a

result of storage tank and pipeline accident events as discussed in the Quantitative Risk

Analysis (QRA) study. Not all emergency situations call for mobilization of same resources

or emergency actions and therefore, the emergencies are classified into three levels

depending on their severity and potential impact, so that appropriate emergency response

procedures can be effectively implemented by the ONGC Emergency/Crisis Management

Team. The emergency levels/tiers defined with respect to this project based on their severity

have been discussed in the subsequent sections with 'decision tree' for emergency

classification being depicted in Figure 5.8.



FIGURE 5-8: EMERGENCY CLASSIFICATION “DECISION TREE”

5.4.4 Level 1 - Emergency

An event that can be dealt with by on-site/location personnel and resources; the event does

not have any effect outside the site and external agencies are unlikely to be involved. There is

unlikely to be danger to life, to the environment, or to Company assets or reputation. The

Disaster Management Plan and relevant procedures are activated; the Site Head is notified.


It is an event which may be dealt by the ONGC Emergency/Crisis Management Team but

requires involvement of wider Company support and external services. The initial event may

be “on-site”, having some effects outside the site or be “off-site”, and external emergency

services will be involved. There is likely to be a danger to life, the environment, or company

assets or reputation. The Disaster Management Plan and relevant procedures are activated;

EMERGENCY

Activate Disaster Management Plan

Mobilization of equipment/human

resources available onsite is sufficient

to contain the emergency

Containment of emergency requires

involvement of additional resources

and local emergency responder group’s

viz. local police, fire brigade etc

NO

YES LEVEL 1

EMERGENCY

YES LEVEL 2

EMERGENCY

Management of emergency requires the

involvement of District/State Disaster

Management Team

NO

YES LEVEL 3

EMERGENCY



local administrative bodies and Emergency Response Groups including ONGC Corporate are

notified.


It is a major event which requires the involvement of District or State Crisis Management

Group. For Company this may result from insufficient local resources and/or because the

incident has broader implications such as reputation, legal prosecution, financial loss etc.

Under such circumstances, the Disaster Management Plan is activated; ONGC Corporate,

District/State Administrative Authorities and other Emergency Response Groups are notified.

The criterion for classification of various levels of emergencies and associated response has

been presented in the Figure 5.9 below.

FIGURE 5-9: EMERGENCY RESPONSE LEVELS

Level Type Criteria for Classification

Level 1 Small Minor medical or injury case requiring no external support

Equipment damage without any significant impact on operation

Minor fire without any personnel injury or plant damage

Net negative financial impact of <1 crores.

Small operational spills

No potential impact on flora and fauna of identified eco-sensitive areas.

Local stakeholder concern and public attention

Level 2 Medium Fire and explosion which requires external assistance

Requires evacuation of injured personnel and locals through assistance from

local emergency groups.

Loss of corporate image and reputation

Adverse impact on environmental sensitivities (if any) within a radius of 1km.

Medium sized spills

Net negative financial impact of 1 - 5crore

Level 3 Large Incident leading to multiples injuries or fatalities

Requires assistance from District/State emergency responding groups.

Adverse impact on environmental sensitivities (if any) within a radius of >1km.

Major oil spills

State/nationwide media coverage

Net negative financial loss of >5crore

5.4.7 ONGC Disaster Management Plan

ONGC has in place a Disaster Management Plan which has been developed to set up the

appropriate mechanism and course of action to mitigate the impact of an Emergency event

viz. blow out, fire, explosion etc. The plan provides a procedure allowing all those involved

in and outside ONGC to mobilize their resources in an orderly manner and react effectively

in time. The plan therefore, aims at immediate response to an Emergency event to prevent

escalation to a Disaster and also the response in the event of such escalation. The plan will be

updated as and when necessary, but at least once in every year by Basin HSE in consultation



with Surface Team, Sub surface Team, Drilling Services and Well Services Group. Also

ONGC has been accredited with ISO 9001:2008; 14001:2004 and OHSAS 18001.

The roles and responsibilities of both ONGC emergency response team to combat with any

emergency situation as discussed in the earlier section are presented in the Table 5.16 below

while the details of the resources available onsite with the Crisis Management Team to

control key emergency events particularly blow outs has been presented in Annex 5.1.



TABLE 5-12: ONGC ON-SITE DISASTER MANAGEMENT TEAM PROFILE

Sl.

No.

Response

Team/Resource Location Facilities Functions

1 Site Control

Room

In case of Emergency at Site, a

Site Control Room will be set

up at a safe distance near the

Site.

Emergency vehicle, Communication

facilities, Mobile Van, Ambulance,

Lighting arrangement and Food shall

be provided at the SCR in the minimum possible time.

Assessment of situation and requirements, tor mobilization of equipment / resources etc.

To pass on the information regarding latest

positions to Emergency Control Room

To keep record of all decisions and messages

received

To keep records of all materials received at site

during Emergency.

2 Emergency

Control Room (ECR)

The control room will function

from Drilling Services (DBC) Control Room, Jorhat

To be equipped with good

communication facilities like

Telephone (2 nos.), Radio

Equipment, Wall Chart showing

Locations of Installations, fire

station, copy of the Disaster Management Plan.

Command and Control of entire Operations.

Round the clock monitoring and flow of

information to & from the site of Emergency.

Maintenance of running record of events and

action taken Casualty list and information to next if Kin.

Preparation of Management Report on the

situation at every 12 Hrs. interval.

Co-ordination with the key personnel's for

guidance and assistance required at site.

Co-ordination with other Oil companies

Co-ordination with Local authorities — Police,

Civil Administration, Hospital & Fire.

Sanction and procurement of the items required

during Emergency.

Arrangement of food, water, shelter, medicine&

logistics etc.,

Information to Public.

Co-ordination -with Regions / Projects and Head

— Quarter.



Sl.

No.

Response


Co-ordination with fire brigade & fire tender

facilities available with different organizations

nearby.

3 On Scene

Commander (OSC)

At initial stage, someone close

enough to the scene of

Emergency (Installation

manager / DIG / senior most

person) will exercise as On

Scene Coordinator. He will take

the charge of the situation immediately.

- Initial assessment at the spot and need for mobilization of sources.

Inform Emergency Control Room in case, the

communication is lost due to disaster. Seek

assistance from nearby rig or installation for

communication.

In case of fire, commands the firefighting

operations till tire service assistance reaches on the scene.

Arrange Ambulance & doctor if required.

4 Chief Emergency

Coordinator

The Head of the concerned

Operational Group will be the

Chief Emergency Coordinator

and will exercise control

through ECR.

- Will keep record of messages and decisions taken to

control the Emergency. He will also appraise the

Basin Manager from time to time on steps taken to control the situation and status of Emergency.

5 Regional Crisis

Management Team (RCMT)

Regional Crisis Management

Team comprises of officers

having experience in handling

major emergency. The RCMT

is expected to be informed

within 30 minutes of

occurrence of incident by the

Mines Manager / Emergency

Control Room. The Team will

immediately proceed to the

location and take action to bring

the situation under control.

- Familiarize itself thoroughly with the manual and its implications

To plan strategies for different Crisis situation so

that all necessary inputs can be mobilized without

loss of time. Frequent mock drill be carried out.

In the event of Crisis, go to the scene of

Emergency, assess the situation and take over all

fronts out and / or fire up o the point of normalizing the well.

Determine the type of assistance required for

handling the Emergency.

To seek guidance and assistance from coordinator



Sl.

No.

Response


group.

Updating the action plan of Disaster management

on the basis of their experience.

Keep them well informed of the technical

development through various journals /

magazines, suggest scope of improvement in

equipment and practices.

6 Support Services

Group

The Support Services Group

will comprise of coordinators

from Central Workshop,

Electrical, Civil, Logistics,

E&T, Health Services and

P&A, Geology and Reservoir

etc. They will provide all

necessary help required by

emergency control room / Site

Control Room / RCMT and be

in constant touch with

Emergency Control Room and

may have to stay at the site of

Emergency

- Support Manager

To identify location of relief camp at a safe

distance from the affected area and arrangement for shelter (tent, cot, chair, blanket etc.)

To arrange food, drinking water, beverage at

relief camp

Maintenance of record of Casualties

Co-ordinate with local Authorities.

Fire Services

Mobilize firefighting person and equipment

onsite.

Information & Communication’s Manager

Ensure Communication facilities

Set up Emergency communication (Walkie-talkie,

VHF etc.) at the Site Control Room.

Electrical

Arrangement of Emergency Gen. Set and Flame

proof lighting at the site.

Logistics



Sl.

No.

Response


Arrangement of transport facilities, cranes, moles

etc for man and material.

Material Management

To assist in issuing of materials

Arrangement of equipment, materials, expertise

etc., as per requirement of Emergency Control Room / RCMT.

Civil

Civil jobs such as construction of temporary road,

control of Oil spread by sand bags or digging of pits, water pumping and storage arrangement etc.

Security

Deployment of Security personals at vulnerable

locations.

Cordoning off the affected site.

Police Help

Sub surface Team (Geology & Reservoir)

To assist in Geological / Reservoir information

about the well

Medical Services

Mobilize first — aid team with adequate medical

facility and ambulance at Emergency site.

Corporate Communication (PRO)

Press briefing with approval of Basin Manager



For Level 3 emergency (refer Table 5.16) apart from the mobilization of onsite Emergency

Response Team as referred above ONGC also need to activate the off-site Disaster Plan to

safeguard the lives and properties of nearby communities with the assistance/support from

local/district authorities

Local/District Authorities – Roles and Responsibilities

I. Deputy Commissioner/ Addl. Deputy Commissioner

Take overall responsibility for combating the Off-site Emergency,

Declare an area of 2 km around the site as Emergency zone.

Direct the District Police, Fire services for warning and evacuating the public.

Direct the team of Doctors headed by the District Medical Officer to attend the

affected people.

Direct the Revenue Officer of the District to provide safe shelter, food and other life

sustaining requirements for the evacuees.

Direct the District Transport Officer to arrange for transportation of victims and

evacuation of the people trapped within the Emergency zone.

II. Superintendent of Police

Mobilize force to the site of Emergency on receipt of instruction from DC / Addl. DC

to cordon off the affected site / area and disperse the unwanted crowd for easy fire

fighting operation / rescue operation.

Post adequate nos. of Police personnel in the following places.

In all the evacuated areas to provide security to the properties of the evacuees.

In the entire Road junction outside the emergency zone to control traffic and priority

for movement of fire tender ambulance etc.

Warning and advising the affected population through unambiguous, reliable and

rapid announcement by the SDIPRO/DIPRO. The information to be given to the

public should be the nature of the incident, the degree of the incident; the steps taken

to control the situation and the Emergency counter measures. The announcement shall

be both in Assamese and Hindi.

Liaison with the Medical co-coordinator for post mortem of the dead bodies, if any,

Any other action as desired by the Dy. Commissioner.

III. District Transport Officer

On receipt of the request from Emergency Control Room, ONGC, the Transport Officer shall

arrange for the dispatch of vehicle to reach the Emergency site immediately. The dispatched



vehicle shall be at the disposal of ONGC until the release order is issued. He also takes up the

action as directed by the Dy. Commissioner / Addl. Dy. Commissioner.

IV. District Medical & Health Officer

On receipt of information form Dy. Commissioner / Addl. Dy. Commissioner about the

Emergency, the District Medical Officer shall extend the facilities available at the Hospital

and make the services of the trained Doctors to provide necessary medical care for

Emergency medical cases. He shall ensure that the Primary Health Centers & Municipal

Dispensaries are equipped with required quantities of drugs & equipments.

V. District Fire Officer

Shall assist in Fire Fighting in case of Off-site Emergency and rescue operations in the

affected area with the help of Civil defense / Home guards etc.

VI. Officer in-charge of Relief Camp

An officer in the cadre of Revenue Inspector shall be the In-charge of the Relief camps. He

shall maintain a record of the evacuees under the headmen, women and children. The

department concerned at the Relief Camps shall provide the following facilities.

Sanitation: This is very important at the Relief Camps. A team of Sanitary Inspector shall

attend the camp round the clock. Latrine facilities shall be provided.

Water: Municipal Board shall arrange storage of Water.

Lights: Assam Electricity Beard shall arrange Electric Lights at the Camp.

VII. District Veterinary & Animal Husbandry Officer

Shall depute as many persons as required (taking in to account the number of Cattle

especially milking animals in the affected areas) to look after the welfare of the cattle and

protect their lives by applying precautionary measures. He shall also be responsible for

arranging food for the Cattle during Emergency.

VIII. District Agriculture Officer

Will prepare an action plan to protect the food grains / standing crops in the Emergency

affected area and will take action accordingly.

IX. Station Director (Door-Darshan)

On receipt of the message from the Superintendent of Police, he will immediately telecast the

Emergency message as given by the Police authority, if required. Similarly, he will also

arrange to telecast periodic review message and completion of Emergency / all clear message.

The section below highlights the sequential action to be performed by the ONGC Emergency

Response Team along with drilling personnel under various emergency situations viz. blow

outs, fire and explosion etc.



Action Plan – In event of Blow Outs

The following actions shall be taken by the Shift — in charge to bring the situation under

control.

(A) On experiencing Kick, following safety actions to be taken, it BOP fails to seal Well

Mouth

1 Alert Crew to ensure escape if situation worsens

Action : Shift I/C

2 Divert flow partially, intermittently or fully to waste pit (safe distance)

Action : Drilling Crew

3 Send SOS message (i) By EPABX (ii) By Emergency Vehicle

Action Shift I/ C

4 Switch off all Engines / Generators

Action: I/C Mech. / Elect.

5 Remove all inflammable material away

Action: Rig Crew (Drilling / Mech. / Elect.)

6 Remove important Records to Safe place


7 Remove costly instruments / equipments to safe place


(B) If the Blow out is sudden and massive while initial safety action could not be performed.

1 Carry out rescue operation for Top man and move other Rig Crew to safe distance.

Action : Shift I/C

2 Send SOS message by Phone and by Emergency vehicle

Action : Shift I/C

3 Reorganize to try operations like BOP, Diversion of flow etc., as listed in (A), if

situation permits,

Action : Shift I/C

4 If heavy spillage occurs, try to contain in the restricted area

Action : Shift I/C

5 Alert the inhabitants, if private residence is near

Action : Geologist / Chemist

As soon as an Emergency is declared and the site is evacuated, Site Control Room will be

established near the Drill site at a safe distance.



Action Plan – Process Leak / Loss of control resulting in Fire and Explosion

1 Shout "FIRE'', "FIRE", "FIRE", "AAG", “AAG", “AAG", "JUI', "JUI', "JUI”,.... In case

of fire

2 Inform Shift. In-charge/Site In-charge at first site of Fire / heavy Gas leakage / Oil spill

Action: Person who notices the incident first.

3 Inform Field Fire Station, Base Fire Station and Base Control Room

Action: Shift I/C. Site I/C.

4 Identify the Source of leakage, isolate and attempt to extinguish tile Fire with hand held

Fire Extinguisher.


5 Nearby source of ignition should be cut off immediately (like stoppage of the cutting /

welding jobs, stopping engines, switching off the Electricity etc.

Action: Shift I/C. Site I/C. Elect. I/C. Mech. I/C.

6 Start Fire water pumps and pressurized Fire Header to extinguish Fire

Action: Mechanics / Shift Operator

7 Inform other GGS to stop supply of Oil & Gas to the affected Installation.


8 If needed, close all wells and shut down the Installation under Emergency conditions.


9 Release over pressure wherever required.


10 Inform nearby Installation for Help.


11 If heavy spillage occurs, try to contain in the restricted area.


12 Fire crew In-charge after arriving at Site will report to the Shift in-charge /Installation

In-Charge and access the situation and position the Fire tender at appropriate place

from where it can be fought effectively.

Action: Fire Crew I/C.

13 The quantum of spillage / Gas leakage shall be briefed by the installation I/C to Fire in-

charge for Fire fighting

Action: Fire Installation I/C.

14 Cooling and quenching of nearby pressure vessel / tanks to be carried out

Action: Fire crew

15 All persons present at the site should assist the Fire crew in tire fighting.

Action: All persons present at site

16 Continuous monitoring of Gas concentration should be done.

Action: Safety Officer/Asst. Shift I/C

17 Entry at Main Gate should be regulated and Contract personals should be removed from

the affected site by CISF.

Action: Area Commander CISF

18 Pass the information and progress to Emergency Control Room at regular intervals.

Action: Installation I/C., Field I/C.



6 Environmental Management Plan & Monitoring Framework

This Environmental Management Plan and Monitoring Framework is a site specific

document for the development drilling of hydrocarbons that has been developed to ensure

that ONGC can implement the project in an environmentally conscious manner and where all

contractors, understand the potential environmental risks arising out of the proposed project

and take appropriate actions to properly manage such risk.

This EMP will be an overview document that will guide environment management of all

aspects of ONGC’s activities within the Block. This EMP will be backed up by more specific

Environmental Action Plans, Procedures and Bridging Documents with the progress of the

well site preparation, development drilling, well testing and site decommissioning activities.

The EMP describes the actions to be adopted in terms of:

National Policies and Regulations

Best Practices and guides

Local Environmental and Social Sensitivities

The Environment Policy of ONGC is presented at Box 6.1.



Box: 6.1: ONGC Corporate Environment Policy



6.1 ENVIRONMENT MANAGEMENT PLANS

The Environment Management Plan details out the mitigation measures to be implemented

by both ONGC and the Contractors during various stages of development drilling of

hydrocarbons within the Khoraghat Extension ML Block. The following environmental

management plans have been formulated in line with the proposed project activities viz. site

preparation development drilling, well testing and decommissioning

Pollution Prevention and Abatement Plan

Waste Management Plan

Storm Water Management Plan

Wildlife Management Plan

Community Management Plan

Site Closure Plan

Road Safety and Traffic Management Plan

Occupational Health & Safety Management Plan

ONGC will ensure communication and implementation of the aforesaid management plans

prior to the commencement of site preparation and development well drilling operations in

the Block. In addition, the mitigation measures for social issues and concerns are also

separately presented in this report. An Emergency Response Plan to address technological

emergency situations viz. blow outs, fires, oil spill etc. etc. that may arise out of drilling

operations has already been discussed in previous chapter. In cases, where there are possible

overlaps, the plans have been cross-referenced to avoid repetition. Additional mitigation

measures to ensure effective management of identified environmental aspects during various

phases of the proposed project have been discussed under the aforesaid plans in the

subsequent sections and summarized in Table 6.1 for ease of reference.

6.1.1 Pollution Prevention and Abatement Plan (PPAP)

Scope

The Pollution Prevention and Abatement Plan (PPAP) is applicable for and encompasses both

construction and operational phase activities for the proposed project which has the potential

to adversely impact ambient air and noise quality, surface and ground water quality and soil

quality of the Khoraghat Extension ML Block .

Purpose

The PPAP establishes specific measures and guidelines aimed at effectively addressing and

mitigating the air, noise, water and soil quality impacts that may arise as result of well site

preparation and access road construction/strengthening, drilling operations and

decommissioning/site closure. The plan also details out roles and responsibilities of ONGC

and the contractors to ensure effective implementation of the plan.



Mitigation Measures & Strategies

The following mitigation measures need to be adopted and implemented by ONGC and its

contractors during various phases of the proposed project to prevent and control air emissions

(both point and fugitive), high noise generation, soil contamination and fertility loss,

contamination of ground water resources and storm water discharge.

A. Control of fugitive and point source emissions

Project Phase Mitigation measures

Construction Vehicles delivering raw materials like soil and fine aggregates will

be covered to prevent fugitive emissions.

Storage and handling of raw material and debris will be carefully

managed to prevent generation of fugitive dust.

Sprinkling of water on earthworks, material haulage and

transportation routes on a regular basis during dry season.



All vehicles utilized in transportation of raw material and personnel

will have valid Pollution under Control Certificate (PUC). Vehicular

exhaust will be complying with the Bharat Stage III specified

emission norms for heavy diesel vehicles.


designated area and stabilized to prevent fugitive dust emissions.

Drilling and well testing Flaring will be undertaken in accordance with the S No. 72 B.1.a


Pollutants from Oil Drilling and Gas Extraction Industry of CPCB.

Locations of flare stack will be governed by the presence of

habitation and sensitive receptors. Care will be taken as all the

proposed exploratory and development wells and GGS are located

very close (less than 200 m) to human settlement.

Duration of flaring will be minimized by careful planning;


An efficient test flare burner head equipped with an appropriate

combustion enhancement system will be selected to minimize

incomplete combustion, black smoke, and hydrocarbon fallout.

Volumes of hydrocarbons flared will be recorded.

Exhausts of engines on the drilling rig diesel generators will be

positioned at a sufficient height to ensure dispersal of exhaust

emissions; engines will not be left running unnecessarily.

Preventive maintenance of DG sets will be undertaken as per

manufacturers schedule to ensure compliance with Sl No 95 GSR

371(E) dated 17.5.2002.

Decommissioning/Site

Closure

Mitigation measures to address the air quality impacts resulting from

vehicular movement, operation of heavy construction machinery and

material handling are similar to those discussed above



B. Control of Noise and Vibration


Construction Selection and use of low noise generating equipment equipped with

engineering controls viz. mufflers, silencers etc

All vehicles utilized in transportation of raw material and personnel

will have valid Pollution under Control Certificate (PUC)

All high noise generating equipments will be identified and

subjected to periodic preventive maintenance.

No night time operation of vehicles and construction activities will

be undertaken.

Engines of vehicles and construction equipment will be turned off

when not in use for long periods.

Drilling Installing acoustic enclosures and muffler on engine exhaust of DG

sets to ensure compliance with generator noise limits specified by

CPCB in accordance with Sl No 94 GSR 371(E) dated 17.5.2002.

Setup effective noise barrier at the fence-line of the site;

Restrict all noise generating operations ,except drilling, to daytime;

Periodic monitoring of noise levels on site and nearby receptors to

ensure compliance with Noise Pollution (Regulation & Control)

Rules 2000.


Closure

Management measures to address noise impacts with respect to operation

of heavy equipments/machinery and movement of vehicles during

decommissioning/site closure phase are similar to those discussed in the

“Construction Phase” of this section

C. Prevention and Control of Soil Quality Impacts


Construction Site preparation and road strengthening/widening activities will be

restricted within defined boundaries.

Avoid construction activities during monsoon season as moist soil is

most susceptible to compaction.

Use appropriate machinery and/or protective boarding during top

soil stripping.

Debris and excavated material generated during construction

activities will be stockpiled in designated areas onsite. No material

will be disposed in adjacent land surrounding the site boundary.

For cleared areas, retain top soil in stockpile where possible on

perimeter of site for subsequent re-spreading onsite during

restoration.

Provide embankment all around the heap of excavated top soil and

cover it with jute mats to avoid erosion by the action of rains/strong

winds.





straw barriers etc. so as to minimize erosion.

Drip trays to be used during vehicular/equipment maintenance and

during refueling operations.

In case of a spill, the spilled soil is to be removed and stored in

hazardous waste storage area

Drilling All chemical and fuel storage areas will be designed considering

HFL


Bunded areas will be designed to accommodate 110% of the volume

of spilled material.

Spill kits will be made available at all fuel and chemical storage

areas. All spills/leaks contained, reported and cleaned up

immediately.

Drip pans/trays will be used in areas identified having spillage

potential but not limited to drill rig engine; electric generator

engine; pumps or other motors; maintenance areas; fuel transfer

areas.

In case of a spill, the spilled soil is to be removed and stored in

hazardous waste storage area


domestic waste will be made in accordance with “Waste

Management Plan”


Closure

Decommissioning at the end of project life/drilling will have some

adverse impacts in terms of increase in soil erosion and would require

adequate mitigation measures to minimize any adverse impacts. The

mitigation measures will be similar to those outlined for construction

phase activities as discussed earlier.

D. Prevention and Control of Surface Water Quality Impacts


Construction Minimize clearing and construction activities during monsoon

season (as far as practicable).

During site preparation and construction, surface water run-off will

be managed through implementation of proper drainage system and

silt trap and sedimentation tank onsite.

Sediment filters and oil-water interceptor will be installed by the

Contractor to intercept run-off and remove sediment before it enters

water courses.

Regular inspection of surface water drainage/diversion system and

sediment controls will be undertaken.

Drilling Run-off from vehicular wash and chemical storage areas will be

channeled through closed drainage system provided with an oil-

water separator prior to silt trap and sedimentation tank to disposal

to nearby drainage channels/surface water bodies. Spill kits will be

made available in these areas.




Drip trays will be used during preventive maintenance of vehicles

and machinery.

Hazardous chemicals and fuel drum will be stored in bunded and

lined area equipped with proper spill control equipment.


domestic waste will be made in accordance with S No. 72 C.1.a


Pollutants from Oil Drilling and Gas Extraction Industry of CPCB

as modified in 2005.


Closure

No significant impact to surface water quality can be associated with

activities during decommissioning/site closure phase. Any possible

impacts that may arise due to surface run-off will be mitigated in manner

similar to that discussed during construction phase activities.

E. Prevention and Control of Ground Water Quality Impacts


Construction No significant impact on the ground water quality can be associated

with the construction phase activities

Drilling The development wells will be sited at a sufficient distance away

from an existing tube well or open well.

Proper casing and cementing of developmental well will be done to

prevent contamination of sub-surface aquifers.

Water based mud to be used as a drilling fluid for the proposed

project

Selection of low toxicity chemicals/additives in the preparation of

water based mud.

Periodic monitoring of ground water quality will be carried out for

village wells located outside the project boundary to assess the level

of ground water contamination, if any.

Storage and disposal of drill cutting and waste mud to be made in

accordance with S No. 72 C.1.a Schedule I Standards for Emission

or Discharge of Environmental Pollutants from Oil Drilling and Gas

Extraction Industry of CPCB as modified in 2005”


Closure

No significant impacts to ground water quality can be associated with

activities during decommissioning/site closure phase



6.1.2 Waste Management Plan

Scope

The Waste Management Plan (WMP) is applicable for all process and non-process waste

streams which are generated during various phases of ONGC’s proposed development

drilling of hydrocarbons in Khoraghat Extension ML Block. The major waste streams

covered under this plan includes drill cuttings, waste drilling mud, wash water, kitchen waste

and sewage. In addition, waste oil and lead acid batteries generated from the proposed project

operations have also been dealt in this plan.

Purpose

The WMP establishes specific measures to ensure proper collection, storage, treatment and

disposal of the identified process and non-process waste streams in accordance with the

applicable national regulations and guidelines12

and also to ensure compliance with ONGC’s

corporate HSE Policy. The plan also outlines roles and responsibilities of both ONGC and the

contractors involved in the implementation of the plan.

Mitigation Measures

The following mitigation measures need to be adopted and implemented by ONGC and its

contractors for the major waste streams identified in the plan.

Waste Quantity Mitigation Measure

Drill Cuttings 212-225

m3/well

Drill cuttings separated from drilling fluid will be

adequately washed and temporarily stored and disposed

in an impervious pit lined by HDPE.

The drilling cuttings pit will be bunded and kept covered

using tarpaulin sheets during monsoon.

Periodic monitoring and analysis of drill cuttings will be

undertaken to establish its nature and characteristics.

Earlier test reports of drill cuttings from AAA Basin has

shown the absence of hazardous nature of the soil

The waste pit after it is filled up will be covered with

impervious liner over which a thick layer of native top

soil with proper top slope will be provided.

Feasibility study for use of drill cuttings for lining or

capping of landfill sites, or as a road construction

material in consultation with nodal authorities

Waste Drilling Mud 10 Use of water based mud as the drilling fluid.

12 “Guidelines for Disposal of Waste – CPCB Oil & Gas Extraction Industry Standard” – EPA Notification

[GSR 176(E), April 1996]

“Guidelines for disposal of Solid Waste, Drill Cuttings and Drilling Fluids for Offshore & Onshore Drilling

Operation” –MoEF Notification, 30th

August 2005




and Drill wash water m3/day/well Use of low toxicity chemicals for the preparation of

drilling fluid.

Barite used in the preparation of drilling fluid shall not

contain Hg>1mg/kg and Cd>3mg/kg

Recycling of drilling mud will be ensured to the

maximum extent possible.

Temporary storage of drilling fluid and wash waste water

will be done in an impervious pit lined with HDPE.

The drilling fluid pit will be bunded to prevent water

overflow during heavy monsoon.

Drilling wash water will be treated through onsite

Effluent Treatment Plant (ETP) to comply with the S

No.72 A(ii) Standard for Liquid effluents of CPCB

effluent discharge standard for oil drilling and gas

extraction industry for reuse and recycling purpose.

Formation water will be stored in HDPE lined pits and

will be injected in injection wells

Kitchen Waste 10-20

kg/day/well The waste will be segregated and stored in designated

waste bins.

All such waste bins will be properly labeled and covered.

The kitchen waste will be disposed in nearest municipal

dumping site on a daily basis through approved waste

handling contractors

Waste oil

Used oil

As generated The hazardous waste (waste and used oil) will be

managed in accordance with Hazardous Waste

(Management, Handling & Transboundary Movement)

Rules, 2008.

The hazardous waste will be stored in properly labeled

and covered bins located in paved and bunded area.

Necessary spill prevention measures viz. spill kit will be

made available at the hazardous material storage area

Storage details of onsite hazardous waste generated will

be maintained and periodically updated.

Adequate care will be taken during storage and handling

of such waste viz. use of proper PPEs by personnel

The hazardous waste so stored (not more than 3 months)

to be periodically sent to ASPCB registered used and/or

waste oil recyclers/ facilities.

Proper manifest as per HWMH Rules, 2008 to be

maintained during storage, transportation and disposal of

hazardous waste.

Sewage 2.4 m3/day

per well The sewage generated will be treated in a combination of

septic tank and soak pit.

Regular supervision will be undertaken for the domestic




waste treatment system to report any overflows, leakage,

foul odour etc.

Lead Acid Batteries 2-3 batteries

per well Will be recycled through the vendors supplying lead acid

batteries as required under the Batteries (Management &


Proper manifest will be maintained as per Batteries

(Management & Handling) Rules, 2001.

Recyclables viz.

paper, plastic,

packaging waste etc.

Depending

on usage Proper segregation and storage of recyclable waste in

designated bins onsite.

Recyclables will be periodically sold to local waste

recyclers.

In addition to the management measures specified for the major waste stream, ONGC will

prepare and update periodically a waste management inventory of all waste streams identified

for the proposed project. Necessary measure will also be taken by ONGC to incorporate

appropriate waste management and handling procedures in the contractor work document and

conduct periodic training of personnel involved in waste handling onsite to ensure proper

implementation of the WMP. In this regard, necessary inspection, record keeping, training

program and monitoring procedures will be established by ONGC and made operational to

achieve proper management of all wastes generated on site.

A typical layout of the environment management plans in a well site is given in Figure 6.1.

The salient features of measures taken to safeguard the environment are given below:

The drill pad will be elevated and concretized

The top soils will be heaped and bounded by a retaining wall

The Waste pits (refer Sec 2.7.1) will be bunded to prevent the overflow of wastewater

ETP will be installed

Oil spill kits will be available near Drill pad and Oil storage area

Fluid and chemicals will be stored in enclosed houses with restricted access

The Hazardous waste will be separated from Non-hazardous waste and stored

separately in enclosed area

Recyclable and non-recyclable waste will be collected and stored separately

Sufficient lighting will be provided

A garland drain will be constructed within the external boundary of the site that will

have a sedimentation tank with oil and water separator



FIGURE 6-1: ENVIRONMENT MANAGEMENT MEASURES AT DRILL SITE



6.1.3 Site Closure Plan

The site closure plan for will identify all the activities which would be performed during the

restoration of a particular site in case the well is not economically viable and no further use of

that particular well bore is envisaged. Along with the well site the approach road connecting

the well will be restored accordingly.

Chronological inventory of activities which would be performed during the closure of the site

are detailed in this section

The following activities have been considered in the closure plan:

Plugging & Abandonment of well: Close the well head properly to prevent any further

leakage

Decommissioning Phase : Removal of the materials form the site

Waste/mud pit closure and reclamation

Reinstatement Phase: regeneration of the land

Handover Phase : Returning the land to the original owner

Plugging & Abandonment of well

As and when the well will be declared as non productive, plugging of the well will be

performed to close and abandon the well to prevent any leakage of oil or gas.

Decommissioning

The decommissioning phase includes activities dismantling and removal of surface facilities

from the well site, removal of construction fill material form site and storage in the Material

Dumping Area. The activities which are envisaged during this phase are:

Waste Management: clean up the site and remove all waste materials e.g. HDPE

liners, any waste material etc. The waste will be dumped in the designated area as per

the guidelines of local pollution control board.

Removing & Dumping of Fill Materials: The fill materials (aggregates, morrum etc)

should be removed mechanically from the site. It will be used for the local road

preparation or dumped in the designated area as filling material.

Road Restoration: The fill materials should be removed and restore the site or it may

be left for further local community use as per the agreement with community.

Waste and mud pit closure and reclamation

Following decommissioning and abandonment of the well site the waste and mud pits (4-5

nos) will be subject to closure through onsite burial of solids in accordance with lease and

landowner obligations and with local, state and national regulations. Reclamation of closed

pits or any other temporary retaining pits, including reserve pits, will be carried out within a



period of one year from well closure/abandonment. As Golaghat district in Assam is

frequented by rains all such reclamation activities will be carried out based on the climatic

conditions and will be in accordance with reasonable landowner's wishes, and/or resemble

and contour of the adjoining lands.

Reinstatement

The reinstatement phase includes all activities for preparation of the soil for agriculture use.

Reinstatement of agricultural land

Sub soil preparation: All stones and other foreign material which are visible on the

ground would be removed. The sub soil would be tilled till a depth of 6” to de-

compaction the soil.

Overlaying of Topsoil: The topsoil would be spread evenly on each of the terraces as

per the thickness specified by the applicable guidelines.

Top soil preparation: The bio manure will be mixed with the top soil to increase its

fertility (if required). Regular water with mulching will be carried out for more

effective soil preparation.

If the preserved top soil volume found less than the required volume than make up top

soil will be out sourced from soil from pond bottom etc.

Seeding of Soil: Seeds of Leguminous crops would be sown on the plots to

continuously improve fertility of the soil.

Testing of fertility: The soil would be tested for fertility as per the standard procedure

of ICAR and compared to the fertility values done during the Pre Project Baseline

Environment Assessment.

Laying of Plot Dividers: The Plot dividers would be put in place as it was before

operation. Sub soil would be used for preparation of the dividers and would be seeded

with grass to hold it in place.

6.1.4 Storm Water Management Plan

Scope

The Storm Water Management Plan (SWMP) refers to the proper management of surface

run-off generated during monsoons for various phases of activities involved in the project.

Purpose

The purpose of Storm Water Management Plan (SWMP) is to ensure prevent and control any

adverse impact of discharge of storm water from the well site and road

widening/strengthening areas to nearby natural drainage channels and community water

bodies. Proper management of storm water runoff will minimize damage to public and

private property, reduce effects of development on land, control stream channel erosion,

pollution and sediment deposition and also reduce local flooding.



Mitigation Measures

Pipe drainages will be provided for diversion roads constructed for the construction of

new bridges and culverts.

Storm water from all longitudinal and cross drainage works will be connected to the

natural drainage courses.

Necessary measures will be undertaken during construction phase to prevent earth and

stone material from blocking cross drainage structures.

Periodic cleaning will be undertaken to cross drainage structures and road drainage

system to maintain uninterrupted storm water flow.

Obstructions that may cause temporary flooding of local drainage channels, during

construction phase will be removed.

Oil traps will be used to separate oil from runoff water

Sediment control measures in the form of silt traps and sedimentation tank will be

provided to treat surface run-off before disposal

6.1.5 Wildlife Management Plan

Scope

The proposed development drilling of hydrocarbons in Khoraghat Extension ML Block may

impart potential impact on local plant and animal species close to the drill sites and access

roads within the Khoraghat Extension ML Block. The likely impacts of the project activities

on the ecological habitat have been addressed in a Wildlife Management Plan prepared to

safeguard local floral and faunal component.

Purpose

The purpose of Wildlife Management Plan is to minimize the impact on natural habitat and

control any adverse impact due to air and noise pollution from drilling and well testing

activities, discharge of untreated waste water from drilling operation, storm water runoff from

the well site and road widening/strengthening activities. The Management Plan details out the

mitigation measures and strategies to be adopted by ONGC and the Contractors during each

phase of the project, at the same time establishing a monitoring network to investigate the

effective implementation of the Management Plan.

Mitigation measures

The drill site will be properly fenced (chain-linked) to avoid straying of any outsider

as well as wildlife;

No temporary electric supply connection line from the grid will be laid for the

proposed project activity. All electric requirements will be supplied from the internal

DG sets.



Noise Levels at the drill site will be controlled through selection of low noise

generating equipment and installation of sufficient engineering controls viz. mufflers,

silencers etc.


The borrow areas and quarries will be located away from forests and ecologically

sensitive areas.

Care would be taken while disposal drill cutting & other drilling waste and discharge

of waste water from the drilling site.

The following measures and strategies needs to be adopted to safeguard the natural habitat

from the possible impacts resulting from the project and its related activities. An

Environment Management Cell (EMC) will be developed for implementation of

environmental mitigation & management plan. Forest personnel and veterinary doctor will be

taken into the management cell for implementing the wildlife management plan. The

environment cell would look after the following measures:

Any wild animal species if trapped during site development or operation of drilling

would be released into suitable habitat;

Proper monitoring of indicator species will be carried out and compared to baseline to

understand any negative impacts;

In case of any accidental injuries to any wild animal by any project related activity,

the EMC’s Veterinary Doctor’s help will be taken

All sightings of sensitive species in and around the project site will be reported and

adequate steps will be taken with the help of forest personnel to reduce conflict

between such animals and project activities or people working at site.

The Environment Compliance Officer will hold training program for all the ONGC

employees and sub-contractor on the applicable practice and mitigation measures

contained within the Wildlife Management Plan.

6.1.6 Road Safety & Traffic Management Plan

Scope

The Road Safety & Traffic Management Plan is applicable to all operation pertaining to

ONGC and contractor vehicular movement viz. vehicle involved in the transportation of raw

materials, project and contractor personnel, drilling rig and heavy equipment transportation to

well site and decommissioning.

Purpose

The Road Safety & Traffic Management Plan outlines specific measures to be adopted and

implemented by ONGC to mitigate any potential impact on community health and safety that



may arise out of movement of vehicles and transportation of drilling rig and heavy

equipments during site preparation, drilling and decommissioning activities.

Mitigation Measures

Project vehicular movement involved in sourcing and transportation of borrow

material will be restricted to defined access routes to be identified in consultation with

locals and concerned authorities.

Proper signage will be displayed at important traffic junctions along the predefined

access routes to be used by construction and operational phase traffic. The signage

will serve to prevent any diversion from designated routes and ensure proper speed

limits are maintained near village residential areas.

The condition of roads and bridges identified for movement of vehicles and drilling

rig will be assessed by ONGC to ensure their safe movement.

Precautions will be taken to avoid damage to the public access routes including

highways during vehicular movement.

Safe and convenient passage for vehicles, pedestrians and livestock to and from side

roads and property accesses connecting the project road will be provided. Work that

affects the use of side roads and existing accesses will not be undertaken without

providing adequate provisions.

Parking of project vehicles along village access roads prohibited. Signposted parking

facilities will be utilized for such purpose.

Any road diversions and closure will be informed in advance to the villagers who are

accessing the defined routes

Traffic flows will be scheduled wherever practicable during period of increased

commuter movement.

Personnel will be deployed at major traffic intersection for control of traffic

Clear signs, flagmen & signal will be set up at major traffic junctions and near

sensitive receptors viz. primary schools in discussion with Gram Panchayat and local

villagers.

Movement of vehicles during night time will be restricted. Speed limits will be

maintained by vehicles involved in transportation of raw material and drilling rig.

Regular supervision will be done by contractor to control vehicular traffic movement

along defined traffic routes particularly near identified sensitive receptors

A Journey Management Plan will be formulated and implemented by the contractor

to control construction and operational phase traffic.

Routine maintenance of project vehicles will be ensured to prevent any abnormal

emissions and high noise generation.



Adequate training on traffic and road safety operations will be imparted to the drivers

of project vehicles. Road safety awareness programs will be organized in coordination

with concerned authorities to sensitize target groups viz. school children, commuters


In addition, ONGC will ensure that all vehicles transporting hazardous substances (fuel oil,

chemicals, etc.) will be properly labeled in accordance with the specifications of the Motor

Vehicles Rules.

6.1.7 Occupational Health & Safety Management Plan

Scope

The Occupation Health & Safety Management Plan (OHSMP) is applicable for all project

operations which have the potential to adversely affect the health and safety of contractors’

workers and onsite ONGC personnel.

Purpose

The Occupation Health & Safety Management Plan (OHSMP) has been formulated to

address the occupational health and safety related impacts that may arise from proposed

project activities viz. development drilling and testing operation of construction

machinery/equipments, storage and handling of fuel and chemicals, operation of drilling rig

and associated equipment, during drilling and decommissioning/site closure.

Mitigation Measures

All machines to be used in the construction will conform to the relevant Indian

Standards (IS) codes, will be kept in good working order, will be regularly inspected

and properly maintained as per IS provisions and to the satisfaction of the site

Engineer.

Contractor workers involved in the handling of construction materials viz. borrow

material, cement etc. will be provided with proper PPEs viz. safety boots, nose masks

etc.

No employee will be exposed to a noise level greater than 85 dB(A) for a duration of

more than 8 hours per day. Provision of ear plugs, ear muffs etc. and rotation of

workers operating near high noise generating areas.

Hazardous and risky areas, installations, materials, safety measures, emergency exits,

etc. shall be appropriately marked.

All chemicals and hazardous materials storage container will be properly labeled and

marked according to national and internationally recognized requirements and

standards. Materials Safety Data Sheets (MSDS) or equivalent data/information in an

easily understood language must be readily available to exposed workers and first-aid

personnel.



The workplace must be equipped with fire detectors, alarm systems and fire-fighting

equipments. Equipments shall be periodically inspected and maintained to keep good

working condition.

Health problems of the workers will be taken care of by providing basic health care

facilities through health centres temporarily set up for drilling base camp.

The sewage system for the camp must be properly designed, built and operated so that

no health hazard occurs.

Adequate sanitation facilities will be provided onsite for the operational workforce

both during construction and operational phase of the project.

Garbage bins will be provided in the camp and regularly emptied and the garbage

disposed off in a hygienic manner.

Training programs will be organized for the operational workforce regarding proper

usage of PPEs, handling and storage of fuels and chemicals etc.

6.1.8 Management of Social Issues and Concerns

Mitigation measure have been outlined to address project related social issues and concerns

in order for ONGC to take proactive steps and adopt best practices, which are sensitive to the

socio-cultural setting of the region.

Providing Job Opportunities

During site construction non technical jobs will be generated. Most of the people employed

during this stage would be semi-skilled. People from adjoining areas especially given

preference through local contractors according to the skill sets possessed.

Ensuring Public Safety

Since the project involves the movement of heavy vehicles and machinery in the area, the

issue of public safety of the villagers, especially children, is an important concern. During the

drilling phase and for the rest of the project activities proper safety measures will be

undertaken both for transportation as well as the other operations. The drill site would be

fenced and gates would be constructed so that the children are refrained from straying into

the site.

The movement of traffic is also likely to disrupt access conditions of the inhabitants residing

close to the approach road. The increase in traffic will have implications on their safety too,

as well as create congestion, potential delays and inconvenience for pedestrians. The

mitigative measures in this regard have been discussed in detail under the Road Safety &

Traffic Management Plan (Section 6.1.5).

Common Property Resources

During the project tenure there might be some sharing of resources viz. land, water, access

routes etc. by the villagers and the contractor workforce. Prior to the commencement of the



proposed activity, a consultation program will be conducted by ONGC with the target groups

and local authorities. The primary objective of such consultation will be to share with the

concerned villagers/stakeholders the objective of the proposed project associated impacts and

their mitigation. The movement of heavy vehicles and machinery might lead to conditions

like disruption of electric wires and telephone wires in the site area and along transportation

routes. These public utilities will be restored back to normal conditions, at the earliest.

Fencing of the well site will lead to in some cases the temporary loss of shortest foot track

routes for the villagers to their agricultural fields. Consultation with villagers will be carried

out in such cases to assist them in finding alternative foot track routes.

Corporate Social Responsibility

Welfare of society has been integral part of ONGC’s commitment. A purview of ONGC’s

social welfare activities pursued in the Financial Year 2012-13 will provide an insight

towards their commitment. Rs. Seventy five lakhs, sixty-seven thousands, three hundred and

sixty-two INR has been spent as Corporate Social Responsibility in Assam-Arakan Basin

where the spending focused on Education, Infrastructure, Sports, Sponsorship, Relief from

Natural calamity, Arts & Culture and Health. The fraction of money spent for Golaghat

District is Eleven Lakhs, thirty-nine thousands and five hundred only. Part of this amount was

spent for tubewell, toilet and furniture for Hatidubi LP School and furniture for Indrapur

Ajarguri School in Uriamghat the closest town to the Khoraghat Extension ML Block. The

entire welfare activities in Assam-Arakan Basin have been attached as Annex 6.1.

The Environmental Management Plan Matrix for the proposed project has been presented in

the Table 6.1.

6.2 EMP BUDGET

The tentative budget for implementation of the environmental management plans was

estimated per year for 2 development wells and provided at the table below:

TABLE 6-1: TENTATIVE BUDGET FOR EMP IMPLEMENTATION

Sl.

No. Particulars of Work

Budget (in lakh

Rs.)

1 Air Quality Management Plan

a. Dust suppression through water sprinkling in the internal unpaved roads

(@Rs. 10000 per month x 9 months x 1 year) 3.47

b. Maintenance of paved internal road and transport route (budgetary

provision is included in operational cost of drilling) 0.00

c. Ambient Air Quality Monitoring -3 monitoring location x 2 wells x

once per month x 12 months (@ Rs. 5000 x 6 samples x 12 months ) 3.60

d. Stack emission monitoring (@ 5000 per sample x 2 sites x 4 stacks x

twice during drilling) 0.80

2 Noise Monitoring



Sl.


Budget (in lakh

Rs.)

a. Ambient Noise Monitoring – (@Rs. 2500 per location x 2 locations x 2

wells x 6 months) 0.60

b. Workplace noise monitoring -(@Rs.2500 per location x 5 locations x 2

wells x 6 months) 1.50

3 Water Quality

a.

Surface Water Quality Monitoring (@ Rs. 5000 x 4 samples from

natural drainages for four seasons, 2 from ETP and 1 from oil/water

separator from 2 wells once each during drilling)

1.40

4

Soil Quality Monitoring (@ Rs. 5000 x 2 samples x once each after

decommissioning and for emergency sampling during accidental

spill over during Site construction and drilling)

0.30

5 Road Safety & Traffic Management

a. Signage in the transport route & its maintenance (Rs. 100,000 + Rs.

10,000 ) 1.10

b. Deployment of traffic personnel in sensitive area – 10 persons (@ Rs.

6000 per month x 12 months ) 7.20

6 Surface Runoff & Soil Erosion Control

a. Two chamber sedimentation tank at each drill site (Budgetary provision

is already included in the infrastructure development cost) 0.00

7 Municipal Solid Waste

a. Provision of two chambered covered collection bins at well site – 2 nos 0.20

b. Transport arrangement of waste from well sites to dumping area 0.50

8 Hazardous waste management

a.

Construction of dedicated hazardous storage area and record

maintenance (construction included under project cost; only

maintenance included n this budget)

0.50

b. Drill Cutting, waste mud and washwater pits; HDPE lined (budgetary

provision in operation cost of drilling) 0.00

9 Surface and Ground Water Protection and Management

a. Surface runoff control measures for chemical storage area, fuel storage

area (budgetary provision is already taken care in earlier section) 0.00

b.

Paved /impervious storage area for chemical storage area, fuel &

lubricant storage area (Budgetary provision is already included in the

infrastructure development cost)

0.00

c. Domestic waste water treatment facility through septic tank & soak pits

at the drill sites (budgetary provision in operation cost of drilling) 0.00

d Commissioning and operational cost of ETP (commissioning cost 10

lakhs for 1 ETP; cost; operational cost Rs. 100000 per well X2 sites) 10.40



Sl.


Budget (in lakh

Rs.)

10 Occupational Health & Safety Management 0.00

a. Provision of appropriate PPE to all workers and its maintenance

(budgetary provision is included in operational cost of drilling) 0.00

b. Provision of drinking water, sanitation facility for all workers

(budgetary provision is included in operational cost of drilling) 0.00

c Provision First aid facility (budgetary provision is included in

operational cost of drilling) 0.00

d Provision of Ambulance facility ONGC has its own ambulance facility 0.00

e Regular health checkup facility provided by ONGC for workers 0.00

f Regular occupational health & safety training 2.00

Total Cost of Implementation of EMP 33.57

It was revealed from the discussion with the locals that there is demand for better road

infrastructure, drinking water facilities and health facilities in the area. ONGC will undertake

a need assessment for development of infrastructure in the areas that public demanded. The

CSR activities of ONGC within the Block will involve;

1. Improvement of road infrastructure

2. Development of surface water based drinking water facilities

3. Provision of health facilities for the local villagers

The cost for the CSR activity will be determined after the need assessment studies conducted

at the Block.



Table 6-2: Environmental Management Matrix

Sl.

No Activity Potential Impact Mitigation

A. Pre-drilling Activities

A1 Siting of well site facility Potential adverse impact on environment in

the vicinity of the drill site

Potential safety issues to local people related

to drill site preparation and drilling operation

Selection of drill site taken into account of local environmental vulnerability

Sufficient distance maintained in between site and nearest habitation

A2 Procurement of land for well sites

and related facilities Loss of agricultural land and crop productivity

Loss of livelihood for affected communities

Provide of compensation for standing crops

Finalization of compensation package in consultation with local communities

Minimal felling of trees and removal of vegetation through proper and careful selection

of site.

A3 Site preparation and road

strengthening/widening Loss of top soil and increase in soil erosion

potential

Alternation in onsite drainage pattern

Minimal felling of trees and removal of vegetation through proper and careful selection

of site.

Site preparation and road strengthening/widening activities to be restricted within

defined boundaries.

Avoidance of construction activities during monsoon season.

Top soil stockpiles to be stabilized and stored in designated areas

Provision of onsite drainage onsite.

A4 Sourcing and transportation of raw

materials Generation of fugitive emission

Community health and safety concerns

Contractor to source raw materials from approved/licensed quarries.

Proper covering of raw material during transportation to be ensured

Periodic water sprinkling along haulage routes near sensitive receptors

Project vehicular movement to be restricted to defined access routes to be identified in

consultation with locals and concerned authorities.

Proper signage to be displayed at important traffic junctions along the predefined access

routes.

Night time movement of vehicles to be restricted

A5 Operation of construction

machinery/equipments Fugitive emissions and high noise generation

Occupational health and safety concerns

Selection of low noise generating equipment

Installation of engineering controls viz. silencers, mufflers

Rotation of workers operating in high noise generating areas



Sl.


Use of proper PPEs viz. ear plugs, ear muffs.

Periodic preventive maintenance of machinery/equipments

A6 Transportation of drilling rig and

ancillaries Generation of fugitive emission


Disruption of public utilities


Periodic water sprinkling along haulage routes near sensitive receptors

Project vehicular movement to be restricted to defined access routes to be identified in

consultation with locals and concerned authorities.

Proper signage to be displayed at important traffic junctions along the predefined access

routes.

Night time movement of vehicles to be restricted

The public utilities viz. telephone and electrical wire to be restored to its original

condition at the earliest.

Movement of rig and heavy equipments to be carried out in accordance with the Road

Safety & Traffic Management Plan formulated.

A7 Discharge of surface run-off Increase in sediment load contributing to

turbidity of receiving water bodies Provision of onsite sediment control measures viz. silt traps, sedimentation tank

Construction work close to the streams or water bodies be avoided during monsoon

Run-off discharges to natural drainage channels/water bodies made to conform to CPCB

Inland Water Discharge Standards.

B. Drilling and Testing

B1 Physical presence of drilling rig and

ancillaries

Temporary change in visual characteristics of

the area Restoration of site to its original condition following decommissioning/site closure

B2 Operation of DG sets and machinery

and developmental drilling Air emissions and high noise generation

Occupational health and safety concerns

Community discomfort

Siting of drilling rig and facilities away from sensitive receptors

Installing acoustic enclosures and muffler on engine exhaust of DG sets

Setting up effective noise barrier at the fence-line of the site;

Exhausts of engines on the drilling rig diesel generators be positioned at a sufficient

height

Preventive maintenance of DG sets to be undertaken as per manufacturer’s schedule.

B3 Casing & cementing of development

well

Damage to subsurface aquifer

Use of low toxicity chemicals

Periodic monitoring of ground water quality be carried out for village wells located

outside the project boundary to assess the level of ground water contamination, if any



Sl.


B4 Storage and disposal of drill cuttings,

mud and process wastewater

Soil and ground /surface water contamination

Use of water based mud as the drilling fluid.


Recycling of drilling mud to be ensured to the maximum extent possible.

Use of HDPE lined pit for disposal of drill cuttings, process wastewater

Disposal of drill cuttings in accordance with CPCB and MoEF guidelines on

management of drilling wastes

B5 Discharge of surface run-off Soil and surface water contamination Run-off from vehicular wash and chemical storage areas to be channeled through closed

drainage system provided with an oil-water separator.

Drip trays to be used during preventive maintenance of vehicles and machinery.

Hazardous chemicals and fuel drum be stored in bunded and lined area equipped with

proper spill control equipment.

Drill cuttings and mud pit be bunded and kept covered during monsoon.

B6 Sewage treatment Occupational health problems of operational

workforce Sewage to be treated using a combination of septic and soak pits

The sewage treatment system (septic tank & soak pit) to be regularly monitored for any

possible overflows, leakages etc.

B7 Flaring during production testing and

process upset

Air emission leading to discomfort to nearby

communities Siting of flare stack considering nearest habitation and sensitive receptor.

Elevated flaring to be undertaken as per guidelines issued by CPCB for Oil & Gas

Extraction Industry.

Duration of flaring to be minimized by careful planning;

C. Decommissioning/Site Closure

C1 Dismantling of rig and associated

facilities

High noise generation and fugitive emissions

causing discomfort to locals Rotation of workers operating in high noise generating areas

Use of proper PPEs viz. ear plugs, ear muffs.

C2 Transportation of drilling rig and

ancillaries

Same as in A6 Same as in A6



6.3 ENVIRONMENTAL MONITORING PROGRAM

Monitoring is one of the most important components of a management system. Continuous

monitoring needs to be carried out for regulatory requirements, to monitor the environmental

quality and to determine performance of proposed mitigation measures. Monitoring

indicators have been developed for each of the activity considering the mitigation measures

proposed. Indicators have been developed for ascertaining the environmental quality and

performance of the EMP implementation through Environmental Quality Indicators (EQI’s)

and Environmental Performance Indicators (EPI’s) respectively which focus not only on

quantifying or indexing activity-environment interactions that may potentially impact the

environment but at the same time also help in comparing different components of

environmental quality against previously established baseline values. Monitoring results will

be to be documented, analyzed and reported internally to Head - HSE. Monitoring

requirements have been described in the following Table 6.3. Frequency of monitoring and

responsibility of carrying out the monitoring have also been presented in the table below.



TABLE 6-3: PROPOSED MONITORING REQUIREMENTS OF THE PROJECT

A) Environmental Performance Monitoring

EPI

No.

Environmental Performance

Indicator (EPI) Monitoring Parameter Location Period & Frequency Responsibility

A. Design & Planning

A.1 Proximity of sensitive

environmental habitat

Distance between the drill site and sensitive

environmental habitat

Site Once in project lifecycle Civil supervisor

A.2 Proximity of nearest habitation Distance between the drill site and nearest

habitation


A.3 Flood History HFL at site

Return period of major floods


A.4 Location and Size of Land Leased Number of land owners affected

Total area leased for drill site (Ha)

Site Once in project lifecycle Civil Supervisor

A.5 Present Crop Cycle Crop period (in months) Site Once in project lifecycle Environmental Supervisor

A.6

Approval / Authorization of

quarries

Validity of the Approval / Authorization Quarry Once in project lifecycle Civil Supervisor

A.7

Land use Land use Type Quarry/ Borrow

Area

Once in project lifecycle Civil Supervisor

A.8 Haul Routes Distance of quarry / borrow area from project site

Condition of haul road

Quarry / Borrow

Area

Once in project lifecycle Civil Supervisor

A.9 Borrowing practices % of contractors sensitized on best practices and

relevant EMP provisions

Borrow Area During site planning HSE Manager & HSE Supervisor

A.10 Undisrupted flow of water in

drainage channels

Number of cross drainage structures planned to

number of actual stream crossings

Site & Road Once in project lifecycle Civil Supervisor

B Approach Road & Site

Development

B.1 Topsoil Area occupied for topsoil storage/ Area planned

for topsoil storage

Site Once during each site

preparation

HSE Supervisor



EPI

No.



B.2 Local drainage pattern Number of Cross Drainage structures constructed

to actual number of cross drainage structures

designed

Site & road Once in project lifecycle Civil Supervisor

B.3 Fugitive emission of dust during

site preparation

Visual observation of dust in air by haziness Site & approach

roads

Daily during site

preparation

HSE Supervisor with Vehicular / Civil

Contractors

B.4 Air emissions from vehicles and

machinery

PM 2.5, PM10, NOx, SO2, CO, HC, VOC based

on emission factors

Visual observation of emissions (black signifying

more pollution)

% of vehicles possessing valid PUC Certificates

Exhausts Once in project lifecycle

Daily

Once in project life cycle

HSE Supervisor with Civil Supervisor,

Drilling/Civil Supervisor through HSE

Supervisor

Drilling/Civil Supervisor through

Drilling/Civil Supervisor through HSE

Supervisor, Contractors operating vehicles

B.5 Noise emissions from vehicles and

machinery

Noise pressure level in dB(A) near noise sources

(5m)

Site & approach

road

Daily during site

preparation

HSE Supervisor

B.6 Supervision of material transport

Number of vehicles reported with overloaded

material / uncovered material

Site Daily during site

preparation

HSE Supervisor with Vehicular / Civil

Contractors

B.7 Accident reporting

Number of casualties / Number of fatalities

Site & Haul

Routes

During life cycle of

project

HSE Supervisor

B.8 Fugitive emission of dust during

material handling and storage

Visual observation of dust in air by haziness Near stockpiles

and storages

Daily during the entire

project life-cycle

HSE Supervisor

C Drilling & Testing

C.1 Gaseous pollutant emissions from

DG Set

Pollutant concentrations in gaseous emissions and

maintenance parameters (air, fuel filters & air-

fuel ratio) of DG sets influencing air emissions

Visual observation of exhaust smoke

characteristics

DG Stack Monthly during drilling &

testing

Daily during drilling &

testing

HSE Supervisor through Drilling

contractor



EPI

No.



C.2 Noise emission from DG Sets Noise pressure level in dB(A) Near noise

sources (5m)

Monthly during the entire

project life-cycle


contractor

C.3 Noise emission from rig

Noise pressure level in dB(A)

Number of cases of workers not using PPE

On the rig floor

Near noise

sources (5m)

Site

Monthly during drilling

Monthly during drilling


contractor

C.4 Accident reporting

Number of casualties / Number of fatalities

Site

As and when accident

occurs


contractor

C.5 Spilled Chemicals/Oil Area of Spill / Quantity Spilled / Severity of Spill

/ Characterization of Spilled Substances for

Contaminants (Heavy Metals, Toxics, etc.)

Site As and when spills occur HSE Supervisor through Drilling

contractor

C.6 Fugitive emission of cement dust

during handling and storage

Visual observation of cement dust in air by

haziness

Near stockpiles

and storages


project life-cycle

HSE Supervisor

C.7 Runoff from temporary storage

areas

Supervision of functioning of conduits / drains,

channels

Site Fortnightly during drilling

phase

HSE Supervisor

C.8 Emissions from Flaring Total CO, total hydrocarbon, Non-Methane

Hydrocarbons, NOx emission estimates based on

emission factors

Flare Stack As and when flaring

occurs


contractor

C.9 Waste water quantity & quality

(Process water viz. rig wash,

formation water etc)

Volume estimate

CPCB General discharge parameters and Oil &

Gas Extraction Industry Standards

At discharge

point

Weekly during drilling

Quarterly during drilling


contractor

C.10 Storm water/wash down water

discharge

CPCB General discharge parameters and Oil &

Gas Extraction Industry Standards

At discharge

point

Depending on generation

particularly during

monsoon


contractor

C.11 Drill cutting storage and disposal Total volume generated

Concentration of hazardous constituents as per

Hazardous Waste Management and Handling

At storage

location

Once during drilling

period


contractor



EPI

No.



Rules

CPCB Onshore discharge standards for Oil & Gas

Extraction Industry

D Decommissioning/ Site Closure

D.1 Noise pressure level in dB(A) Near noise sources (5m) Site & Approach

road

Once per site HSE Supervisor through Drilling & Civil

contractor

D.2 Air emissions from vehicles PM10, PM2.5, NOx, SO2, CO, HC based on

emission factors

Visual observation of emissions (black signifying

more pollution)

Exhausts Once in project lifecycle

Daily

HSE Supervisor through Vehicle/Civil

contractor

D.3 Fugitive emission of dust during

transport of drilling facilities

Visual observation of dust in air by haziness Near stockpiles

and storages


activity

HSE Supervisor

D.4 Site restoration Visual observation of :

Clearing of decommissioning waste

Leveling of site

Relaying of top soil

Regeneration of top soil

Site Daily during

decommissioning

Civil Supervisor with HSE Supervisor

B) Environmental Quality Monitoring

EQI No

Environmental Quality Indicator (EQI)

Monitoring Parameter Location Period & Frequency Responsibility

A Approach Road & Site Development

A1 Soil Fertility Fertility parameters like pH, NPK ratio, Total

Carbon, etc.

Site & adjacent areas Once before site preparation HSE Supervisor

A2 Quality of water Analysis of Parameters as per CPCB Use-class Natural drainage channel

receiving run-off discharges

Monthly during site and

road works

HSE Supervisor

A4 Ambient Air Quality Measurement of PM10, PM2.5, NOx, SO2, CO,

HC using ambient air sampler

At Surrounding receptor

points

Monthly during site and

road works

HSE Supervisor



EQI No

Environmental Quality Indicator (EQI)

Monitoring Parameter Location Period & Frequency Responsibility

A5 Ambient noise quality Hearing / perception

Measurement of Noise Pressure Level in dB(A)

At surrounding receptor

points

Daily site and road works

Monthly site and road

works

HSE Supervisor

A6 Soil Contamination Analysis for suite of contaminants (heavy

metals, TPH, organics, pesticides).

Site, adjacent areas and

Waste disposal site

In event of spills over an

area of 10 sq.m

HSE Supervisor

B Drilling & Testing

B1 Ambient Air Quality Measurement of PM10, PM2.5, NOx, SO2, CO,

HC , using ambient air sampler


points

Monthly during drilling and

testing

HSE Supervisor

B2 Ambient noise quality Hearing / perception



points

Daily during drilling and

testing

Monthly during drilling and

testing

HSE Supervisor

B3 Soil Contamination Analysis for suite of contaminants (heavy

metals, TPH, organics, pesticides).

Site, adjacent areas and

Waste disposal site

In event of spills over an

area of 10 sq.m

HSE Supervisor

B4

Quality of water Analysis of Parameters as per CPCB Use-class Natural drainage channel


Monthly during drilling &

testing

HSE Supervisor

C Decommissioning / Closure

C1 Ambient noise quality Hearing / perception



points

Daily during

decommissioning

Monthly during

decommissioning

HSE Supervisor

C2

Quality of water

Analysis of Parameters as per CPCB Use-class Natural drainage channel


Once after

decommissioning

HSE Supervisor

C3 Ambient Air Quality Measurement of PM10, PM2.5, NOx, SO2, CO,

HC , using ambient air sampler


points

Monthly during

decommissioning

HSE Supervisor

C4 Soil Fertility Fertility parameters like pH, NPK ratio, Total

Carbon, etc.

Site & adjacent areas Once after site restoration HSE Supervisor



7 Disclosure of Consultants

SENES Consultants India Private Limited (SENES India) is a professionally managed,

fast growing, wholly owned subsidiary of SENES Consultants Limited (SENES), Canada.

SENES specializes in the fields of energy, nuclear, environmental and social sciences with

offices spread across Canada, the United States, South America and India. SENES has been

operational in India for more than ten years having Head Office in New Delhi with branch

offices in Kolkata, Hyderabad and Mumbai with all supportive infrastructure necessary for

project implementation.

SENES India has accumulated a wide body of knowledge from its National and International

Oil and Gas experience worldwide, including the EIAs for upstream oil & gas projects for

Ensearch Petroleum in Jordan, Premier Oil in Assam, Geopetrol in Andhra Pradesh, Eni India

in Andaman Sea, ONGC in Mizoram, Cairn Energy in Rajasthan and Gujarat, British

Petroleum in West Bengal, etc.

SENES India was responsible for carrying out the EIA for development drilling of

hydrocarbons at Khoraghat Extension ML Block. The team deployed for the proposed project

is provided below:

Salil Das: EIA Coordinator

Mangesh Dakhore: Risk Assessment Expert

Dhritiman Ray: Water Quality Expert

Avinandan Taron :Socioeconomic Expert

Abhishek Roy Goswami: Ecology and Biodiversity Expert

Indrani Ghosh: Air and Noise Quality Expert

Subhradeb Pramanik: Risk Assessment Specialist

Debabrata Ghosh: Environmental Specialist

Sk. Nasiruddin Rahman: GIS and Mapping Specialist

The EIA report preparation have been undertaken in compliance with approved MoEF ToR

and the information and content provided in the report is factually correct for the purpose and

objective for such study undertaken.

SENES has already obtained QCI Accreditation under the QCI-NABET Scheme for

Accreditation of EIA Consultant Organizations vide certificate no: NABET/ EIA/ 1013/043

dated 9th October 2010. The QCI/NABET accreditation certification is provided in the

following page.

EIA for development drilling of hydrocarbons at Khoraghat ...

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