Remediation process optimization: A status report

REMEDIATION Summer 2007

Remediation Process Optimization:A Status Report

Sriram Madabhushi

Tom O’Neill

There are hundreds of contaminated sites with remediation systems that require evaluation and

modification to accomplish cleanup goals. These systems are operating well past projected cleanup

schedules, cost more than projected to operate, and may not be as protective of human health

and the environment as planned. Remediation process optimization (RPO) is an effective method

to assess the progress of a system toward achieving cleanup goals within desired time frames

and to make the necessary changes in order to reach those goals. Eight main components to the

RPO process are evaluated during a review and an implementation plan of recommended changes

to the system is developed. Follow-up and tracking are essential to successful RPO programs.

In this article, the authors present a summary of a recent Technical and Regulatory (TechReg)

Guidance Document (Interstate Technology and Regulatory Council [ITRC], 2004) and related

Technology Overview Series on Advanced Topics in RPO (ITRC, 2006) in a distilled form. Oc 2007

Wiley Periodicals, Inc.

INTRODUCTION

The science and engineering of remediation of contaminated sites has advancedsignificantly in the past decade. Many lessons learned and changes in our approach toremediation in the last few years have made the site cleanups more successful. However,for the foreseeable future, federal, state, and private-sector organizations will continue tospend billions of dollars on charactering and assessing contaminated environmental mediaand on selecting, constructing, operating, maintaining, and monitoring remediationsystems. Little effort has been put toward evaluating the effectiveness of these systems andtracking the progress toward achieving goals.

The initial assumption, as the various environmental cleanup statutes and theirimplementing regulations evolved, was that these programs could follow a “study, design,and build” paradigm. However, years of experience have led to the realization that thesignificant uncertainty inherent in environmental cleanup requires more flexible, iterativeapproaches to manage uncertainty. Uncertainty, as demonstrated by frequently missedtarget dates, has forced the development of mechanisms that allow for both the systematicreevaluation of initial objectives and the continuous improvement and optimization ofremediation technologies and techniques. These mechanisms and reevaluations are knowncollectively or generally as remediation process optimization (RPO). It is also known asremediation system evaluation (RSE), or remedial optimization. The Interstate

c© 2007 Wiley Periodicals, Inc.Published online in Wiley Interscience (www.interscience.wiley.com). DOI: 10.1002/rem.20133 47

Remediation Process Optimization: A Status Report

Select an independent, multidisciplinary

RPO review team

Select a site for an RPO review

Collect data on:

• CSM

• ARARs

• RA tech. selection

• Monitoring data

• System effectiveness

Optimize by:

• Minimize risks

• Evaluate costs

• Evaluate time of RA

• Maximize efficiency

Develop:

• Remedial processes optimization implementation strategy

• Exit strategy

• RPO recommendations

Track:

• Optimization continuing?

• Progress toward closure?

• Periodic review needed?

• RPO goals achieved?

SeeExhibit2

Exhibit 1. Overview of conducting an RPO evaluation

Technology Regulatory Council (ITRC) RPO team developed a guide to evaluatingremediation systems (ITRC, 2004). With schedules for projects that are in the operationand maintenance or long-term remedial action phase being frequently measured not inyears but in decades, RPO is not an option but a necessity.

The guidance describes the general regulatory and technical framework for evaluatingremediation processes, regardless of the type or complexity of the remedy. Untilrecently, RPO has been associated with the “how” of remediation, such as thetechnologies in place. The ITRC RPO document looks at not just the “how” of sitecleanup but also at the “why.” The “why” can be described as the conceptual site model(CSM). The CSM considers all factors involved with the site remediation, such as theenvironmental and land-use (current and future), site-specific chemical and geologicalconditions, and the regulatory environment. Exhibits 1 and 2 detail the RPO process for atypical site. Exhibit 1 shows the steps involved in the RPO review process, whereasExhibit 2 highlights some of the actual steps involved in RPO evaluations.

WHAT IS REMEDIATION PROCESS OPTIMIZATION?

Remediation process optimization is the systematic evaluation and enhancement ofremediation processes to ensure human health and the environment are being protectedover the long term at minimum risk and realistic cost. The value of optimization ineffectively and objectively setting and attaining remediation goals has been gaining

48 Remediation DOI: 10.1002.rem c© 2007 Wiley Periodicals, Inc.


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Exhibit 2. Details of RPO evaluation process

acceptance over time by practitioners and regulators and now RPO is becoming acommon practice in many remediation programs nationwide.

The key elements of RPO include:

� appropriate use of the up-to-date conceptual site model (CSM);� flexible remedial action (RA) operations considering technology limitations and risk

assessments;� when necessary, use of treatment trains for each target zone;� developing performance objectives for each element of each treatment train;� developing an exit strategy for each remedy component considering life-cycle factors;� using cost analysis as a decision-making tool with the requirement that protectiveness

must be maintained or improved;� considering life-cycle factors in remedial design; and� continuously evaluating of all of the above through RA operations.

WHAT THE REGULATIONS SAY ABOUT RPO

At the outset, it can be stated that all regulations one way or the other support thephilosophy behind the RPO—as RPO encourages protection of human health and the

c© 2007 Wiley Periodicals, Inc. Remediation DOI: 10.1002.rem 49


environment. It tries to answer if any potential threat to these concerns exists because ofthe failure or inappropriate results of the system in operation. An understanding of theregulatory environment for any candidate RPO site is critical, as regulatory requirementscan strongly influence which elements of a remedy can be targeted most successfully foroptimization. Most major regulatory programs—Comprehensive EnvironmentalResponse, Compensation and Liability Act (CERCLA), Resource Conservation andRecovery Act (RCRA), and state-equivalent (US EPA–delegated or other) programs,state hazardous waste management programs, underground storage tank (UST) programs,Brownfields programs, voluntary cleanup programs, and so on—contain language thataddresses periodic effectiveness reviews and optimization of remediation systems.An understanding of the

regulatory environment forany candidate RPO site iscritical, as regulatory re-quirements can strongly in-fluence which elements ofa remedy can be targetedmost successfully for opti-mization.

For example, the CERCLA process involves site and risk characterization during thepreliminary assessment (PA), site inspection (SI), and remedial investigation (RI); analysisof applicable or relevant and appropriate requirements (ARARs), remedy screening, anddetailed analysis of remedial alternatives during the feasibility study (FS); anddocumentation of the remedial action objectives (RAOs) and response actions required toachieve the RAOs in the record of decision (ROD), or determination that no furtheraction (NFA) is warranted in an NFA decision document.

CERCLA requires periodic effectiveness reviews to assess remediation progress. TheRPO process is typically implemented after final RAOs remedial alternatives, andperformance metrics are documented in the ROD and the remediation action system is inplace. At sites where contaminants remain in place, a long-term monitoring phase isrequired to ensure that the remedy remains protective. This phase involves long-termmonitoring and five-year reviews until such time as the property is considered suitable forunrestricted use.

The RCRA permitting framework contains provisions for periodic assessment of theeffectiveness of corrective action. This routine effectiveness report provides anopportunity to view progress and fine-tune the remedy. However, this assessment is notthe same as the RPO process, which is far more extensive.

Many states have authority under either CERCLA or RCRA to conduct site cleanupoperations or oversee the cleanup operations of others. States, in fact, have initiatedcleanup programs under their own regulatory framework for both publicly funded siteremediation and responsible party oversight. As a result, the states have many of the sameregulatory interests in RPO, as mentioned above for CERLCA and RCRA.

HOW TO PERFORM AN RPO EVALUATION

There are several steps involved in performing an RPO evaluation. The scope of any RPOevaluation depends on the particular goals of the lead agency and the nature of the site andRA to be evaluated; however, several elements of RPO are common to all suchevaluations. The following steps should be conducted for RPO:

� identify whether the site is appropriate for RPO—return on the investment in RPOis likely high;

� build an RPO review team;� develop an exit strategy assessment;� evaluate remedy performance;� conduct other RPO review elements;



� optimize remedy;� conduct cost/benefit analysis;� implement optimization strategy; and� track action items/implementation.

ELEMENTS OF RPO PROCESS

Site Selection Criteria

Site selection criteria have been developed based on observations from conducting RPOor RPO-like reviews at hundreds of facilities nationwide. Virtually all long-term remedialaction sites—irrespective of how large or small the site may be and no matter what stagethe remediation system operation is in the cleanup cycle—can benefit from RPO. RPOnot only redirects attention to potentially overlooked operation and maintenance issues,but also serves to reassure stakeholders that based on the available information the courseof action being undertaken is sound. However, because there are up-front costs associatedwith performing an RPO evaluation and an interest in not overburdening site managersand regulators, prioritizing sites for RPO is appropriate.

Virtually all long-termremedial action sites—irrespective of how largeor small the site may beand no matter what stagethe remediation systemoperation is in the cleanupcycle—can benefit fromRPO.

There are three primary criteria for prioritizing sites for RPO:

1. Concern that the current system is not achieving remedial goals effectively orefficiently (e.g., protectiveness of the remedy may be in question, or the rate ofprogress toward achieving site cleanup criteria may be below expectations (seeExhibit 3);

2. There is an imminent major change in the management approach (e.g., changein the lead agency, change in the land ownership or change from conventional torisk-based approach, etc.); and

3. High annual operation and maintenance costs associated with systems anticipatedto operate for many years.

Other prioritization considerations include (1) sites with persistent contaminantsources, such as landfills or DNAPL releases; (2) sites with complex hydrogeology orgeochemistry that is limiting the effectiveness of the response action; (3) sites for whichdecision documents have been in place for 10 years or longer; and (4) sites where cleanupis expected to take more than 10 years.

Some of these criteria are subjective and case-dependent in nature, but they provideuseful guidelines for determining which sites are most likely to benefit from RPO. Forexample, the threshold for what may be considered “high annual operating cost” is relativeto the fiscal constraints affecting the funding agency/organization. However, it usually isinappropriate to establish minimum criteria or rules of thumb for identifying RPOcandidate sites based on operating costs or other operation and maintenance items alone.Some sites with low annual operating costs may still pose significant risk to human healthand the environment, and sites anticipated to be shut down in the near future couldbenefit from an RPO review of the closure process or site completion criteria. However,sites with very low annual operating costs or sites with anticipated shutdown within oneyear should be closely screened to determine whether RPO is appropriate.



An example of a system that may not be achieving its remedialgoal and where protectiveness may be in jeopardy:

A pump-and-treat system is installed at a trichloroethylene (TCE)-contaminated site with the primary goal of controlling off-site plumemigration to prevent the plume from impacting a nearby watersupply aquifer. A secondary goal is TCE mass removal to achievethe regulatory cleanup goal of 5 ppb of TCE in groundwater.Although the system has been in operation for more than eightyears, monitoring data are inconclusive regarding effective captureof the plume by the extraction well network. As a result, thedowngradient water supply aquifer may be in jeopardy. Further,mass removal has reached an asymptote, and the effectiveness ofthe remedy for achieving the 5 ppb goal in a reasonable time frameis in question.

This site should be considered a high-priority candidate for RPOgiven the concern of ineffective hydraulic control of the plume. TheRPO team can evaluate the groundwater monitoring network,historical trends in TCE concentrations and groundwater elevations,and flow-and-transport models to determine whether capture isbeing achieved or if additional data collection and evaluation arenecessary. The RPO team also would evaluate the effectiveness ofmass removal and progress toward achieving the 5 ppb cleanupgoal. If appropriate, the team can assess and recommendalternative remedial strategies or revised cleanup goals.

Exhibit 3. Example of a quick system check to identify potential site for RPO

The site selection criteria are aimed at understanding how appropriate the site is foran RPO review. The return on the investment in putting together a RPO review should,at the minimum, exceed the costs incurred for such review and implementation of therecommendations. Of course, in many cases, the return can be substantial in terms ofimproved protectiveness due to the optimized remediation process.

After the site is selected for RPO, there is a variety of data that can be used for anRPO review. Most of this information can be extracted from already available documents,reports, and administrative records. Some of these data can be RAOs, primarycontaminants of concern, descriptions of all RA components and their current status,documented RA performance metrics, costs associated with historical and currentoperation and maintenance, long-term monitoring costs, and so on.

Building an RPO Review Team

The professionals conducting the RPO evaluation should be carefully chosen for theirobjectivity, technical qualifications, and experience. The team members should be free ofpotential conflicts of interest and should provide a “fresh view” of the project. An



independent review is critical for identifying characterization and remediationdesign/performance issues that may have been overlooked by the previous or currentproject team. Those individuals who have had past involvement in decision making at thesite may not have an unbiased perception of the current state of the system or thepotential need for change. Qualified personnel from the sponsoring agency who have notbeen directly associated with the subject project would be acceptable; however, the use ofstaff from the design or operation and maintenance contractors typically is not appropriatedue to possible conflicts of interest. Outside (third-party) contractors or representativesfrom other agencies or institutions could be suitable candidates for the RPO review team.

It is very important to include highly experienced technical and regulatory personnelon the RPO review team. The team members must have broad experience in regulatoryrequirements and policy interpretations; hydrogeology; geochemistry; risk and exposureassessment; remediation design, operation, and optimization; and related activities. Theteam should include regulatory specialists, engineers, hydrogeologists, chemists, and riskassessors, all of whom have a wide background in current best practices, innovativetechnologies, and optimization approaches and tools. Important support may be requiredfrom other disciplines, potentially including statistics, modeling (groundwater flow,contaminant transport and fate, exposure/uptake), cost engineering and estimating, riskcommunications, and contracting. The composition and size of each RPO review teamshould be based on the nature of the site and the administrative and technical challengesfaced.

Lastly, the team must have the highest level of authority possible to conduct the RPO.Proper authority will aid the team in their work by breaking down the often-naturalresistance to review and perceived criticism, which is never the goal of an RPO team. Theauthority should also come with incentives. The team’s recommendations forimprovement must be followed up: viable recommendations must be funded, and otherrecommendations properly evaluated by the RPO team and management incentivesapplied for compliance. More information on challenges to RPO will be presented later inthe article.

Exit Strategy Assessment

An exit strategy for a site is simply the detailed plan for achieving the RAOs. Statedanother way, the RAOs are the overall goals that must be met for the site to either achieveNFA designation or be approved for closeout or reuse. An exit strategy represents aformalized long-range process for taking the site from its current state to closure or to itsbest long-term use. The strategy represents a plan to actively manage the site and makedecisions at various points that will best tailor the remediation and monitoring efforts toachieve the RAOs in the most efficient and effective manner. The strategy is bestdeveloped with consideration of stakeholder and regulatory agency concerns, resourceconstraints, and technical realities; it also includes well-defined means to measureprogress and a desired timeline. A well-developed exit strategy contains six elements:

An exit strategy representsa formalized long-rangeprocess for taking the sitefrom its current state to clo-sure or to its best long-termuse.

1. Statement of and basis for the RA goals;2. Summary of the CSM, including a description of the future site land use;3. Decision tree, flow chart, or defined sequence of remedial activities and contingency

triggers;



4. Clearly established process to evaluate performance measures relative to decisionparameter;

5. Provisions for periodic reevaluation of the project goals and RA decisions (contin-gency planning); and

6. Means to verify cleanup following cessation of active remediation.

During the RPO, the exit strategy is assessed for any possible improvements. This canbe accomplished by evaluating mainly the RAOs, CSM, and the RA strategy and decisionlogic.

Evaluating the RAOs, which are normally found in a decision document, involvesverifying that the goals are measurable and realistic. Realistic goals are ones that can beachieved with the current technology in a reasonable time frame. RAOs are normallybased on defined standards, such as maximum contaminant levels (MCLs), or they can bederived using a risk-based approach. In either case, it is important to revisit the riskassumptions that were made at the time the RAOs were established to ensure they are stillvalid.

A CSM is a comprehensive description of all available information about siteconditions—such as the nature and extent of the contamination, the site geology andhydrogeology, receptors and potential receptors, and current and future land use thatcould influence the remedy design, selection, or performance. The CSM is a livedocument that needs to be periodically revised based on the latest site investigations. AnRPO evaluation will review and revise the CSM appropriately.

The last part of the exit strategy assessment involves verifying that the approach toachieving closure or reuse is logical and realistic and will continue protecting the currentand future human health and ecological receptors during and after the remediation. As theinterim goals are accomplished, the remediation activities (e.g., extraction from specificwells) or components (e.g., air sparging) can be reduced or eliminated (in situ treatmentof source area) prior to site closure or attainment of long-term goals when continuation ofthese activities no longer contributes meaningfully to progress toward the RA objectives.In many cases, the existing flow chart or decision tree can be evaluated to ascertain thatthe current field conditions are reflected in the decision process and collected data can beused to assess the progress using the metrics documented. At the end of this review, theremust be a clear understanding of the end point for remediation and the process forverifying if it is achieved, along with provisions for any potential contingencies.

Using field data obtainedin the form of contaminantconcentrations, groundwa-ter elevations, free-productthickness, mass removalrates, system operationalhistory, and system operat-ing parameters will allow acomparison of cleanup cri-teria to the RAOs.

Evaluate Remedy Performance

Remedial performance, the actual performance of the system, and monitoring programsare all evaluated under this element of the RPO process.

Using field data obtained in the form of contaminant concentrations, groundwaterelevations, free-product thickness, mass removal rates, system operational history, andsystem operating parameters will allow a comparison of cleanup criteria to the RAOs. Avariety of analytical tools are available to conduct performance evaluations. Simple graphscan be important in analyzing the system performance data for each well, for plottingcontaminant or geochemical data or for evaluating mass removal rates. Potentiometricsurface maps under pumping and nonpumping conditions are helpful in assessing thecontainment or in analyzing capture zones. Complex statistical tools or geographic



information system software can be utilized in enhancing the data visualization capabilitiesso that a high level of analysis can be performed when warranted. A time series ofcontaminant concentration maps also can help in visualizing the contaminant plumebehavior over time and confirm the performance of the remedy.

Analyzing the system operating parameters can be performed to evaluate theperformance of individual components of a remedy. By identifying performanceobjectives, such as criteria that measure the operational efficiency of each technology andmeasurements to demonstrate that the remedial component operates efficiently, thepractitioner can ensure that any operational adjustments or design modifications for thesystem is appropriately conducted. Then, various parameters can be measured andanalyzed to evaluate the performance data.

Often, the system downtime is reflective of the system efficiency. By understandingthe causes of system malfunctions—if it is a recurring problem or how the reaction timehas been to get it back on line—one can estimate how efficiently the system has beenworking. Unless the system performs effectively, high uptime may not be meaningful. Atthe end, the overall effectiveness and efficiency of the system will help evaluate thepotential for a successful remediation.

Monitoring program evaluation is another important aspect of the remedyperformance. Regardless of the RA selected (active or passive, engineered or natural),evaluation of monitoring programs should be an integral part of RPO at all remediationsites with groundwater contamination. Analysis of monitoring data is the key element intracking and assessing progress of the RA toward achieving the stated RAOs. The purposeof the monitoring network evaluation and optimization is to ensure that adequate data arecollected to allow evaluations of remedial processes, system performance, and systemsuitability and that the collection of superfluous data are eliminated. Evaluating amonitoring program involves assessing of the following elements:

Analysis of monitoring datais the key element in track-ing and assessing progressof the RA toward achievingthe stated RAOs.

� number of monitoring points;� spatial (horizontal and vertical) relationship of monitoring points to source areas,

remedial components, compliance points, and edges of the contaminant plume;� monitoring frequency;� target analytical parameters; and� sampling and analysis protocols.

Remedy Cost Efficiency Assessment

Another element of the RPO evaluation process focuses on a review of the cost efficiencyof the remediation systems and monitoring program. This evaluation compares the actualoperation and maintenance cost of a remediation system against projected cost—whichwas one of the criteria used to select the remedy from among other alternatives—and itsprogress toward achieving the RAOs (e.g., containment or contaminant mass removal).

In order to properly evaluate the cost efficiency of a system, both cost data andperformance data are required. By simply comparing the projected and actual costs of thesystems operation and maintenance (on a monthly or other periodic basis), one candetermine how efficiently the system is performing. Some of the costs to consider as partof operation and maintenance are labor, materials, utilities and fuel, monitoring, sampling



$0

$20,000

$40,000

$60,000

$80,000

$100,000

$120,000

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Cumulative JP-4 Recovered (Gallons)

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Exhibit 4. Cumulative costs versus cumulative product

recovered. In the shaded area, the product removed is indicating

steep associated costs

and analysis, equipment leases, offsite disposal fees, and administrative costs. Again, byidentifying the capital costs for upgrades and modifications, one can also determinewhether it is worth the effort to upgrade a system. Cost-efficiency plots for everyoperating remediation system provide another way to measure the efficiency of thesystem. Plots such as cumulative cost versus cumulative mass removed (see Exhibit 4) orcost per unit mass removed versus time can be useful in directly visualizing any decreasesin the system efficiency and making appropriate corrective decisions. Estimating andevaluating life-cycle costs—which refer to the total project cost across the lifespan of aproject, including design, construction, operation and maintenance, and closeoutactivities—is an important part of an RPO evaluation because life-cycle costs estimate thecost of an RA from design through response complete. A life-cycle cost analysis is a morerealistic method of comparing costs for alternatives than simply comparing initial costs.Life-cycle cost analyses evaluate the total cost of ownership over the life of the project,including interest expense, length of service life of the units or components, maintenance,and operating costs. As used herein, a life-cycle cost analysis compares the present worthof the total annual costs of ownership for different RAs by estimating costs in today’sdollars and amortizing those costs over the life of the project.

Remedy Optimization

After reviewing the exit strategy and validating it in the context of the refined CSM andregulatory framework and after cost and performance data for the current remedy areevaluated and a need for system optimization is identified, modifications to the currentremedial approach can be considered. Modifications might be made to improve the overallexit strategy or the effectiveness (protectiveness) of the remedy or to reduce the costwhile maintaining or improving its protectiveness. Frequently, a balance must be struckbetween competing interests. Some of these changes may require amendments to formaldecision documents. Early involvement of regulators and stakeholders in the RPO canfacilitate acceptance and implementation of the modifications.

The first step in the remedy optimization is the optimization of the exit strategy. TheRPO review team should recommend refinement of the exit strategy based on theiroverall remedy review. The RPO report should address the overall protectiveness of the



remedy and the likelihood of attaining the cleanup goals as currently identified; it shouldalso provide recommendations to enhance protectiveness, to improve the likelihood ofachieving the RA objectives, and to reduce the time required to complete the RA.

The second step is the remedial system optimization, in which the extraction systemsand/or treatment systems are evaluated in order to suggest any modifications for anoptimization of the entire system. The modifications can be minor suggestions to existingsystems or a major revamp by replacing the existing components or systems.

The final step is the monitoring optimization, in which the monitoring program istailored to ensure that every sampling point has a specific purpose with overallprotectiveness completely maintained. By using an iterative process, the data quality canbe enhanced while in the process reducing the resources being used. The scale ofmonitoring optimization can vary from individual sites to an installationwide monitoringprogram. Monitoring parameters and sampling procedures are reviewed in order to addor remove target analytes that are appropriate based on current site conditions. Thenumber and locations of monitoring points as well as the frequency of sampling at theselocations can be evaluated to avoid any redundancies or by adding locations to fill in datagaps, as needed.

Cost Benefit Analysis

The RPO review team should assess the costs—in terms of time, resource consumption,public perception, and dollars—associated with implementing each RPOrecommendation against the benefits (e.g., enhanced protectiveness, reduced time or costto achieve RA objectives) that would be realized. For example, the operation andmaintenance costs of the existing remedy can be directly compared to the estimated capitaland operation and maintenance costs associated with implementing a modified strategy ortechnology (this is a cost versus cost comparison, not a cost versus benefit comparison). Insuch an example, a cost/benefit analysis can be performed using life-cycle costs and theestimated period of RA operation required to achieve RA objectives to calculate an NPVfor each recommended modification/alternative. The calculation of the present value ofthe proposed modification must carefully consider the appropriate discount value.

There are several references available that explain life-cycle cost estimating, includingUS EPA (2000) guidance, several standard industry practices developed by the AmericanSociety for Testing and Materials (2003), a Department of Energy–funded publicationentitled Guide to Computing and Reporting the Life-Cycle Cost of Environmental ManagementProjects (Shultz & Weber, 2003), and Life Cycle Cost Analysis (ITRC, 2006).

ADDITIONAL RPO CONSIDERATIONS

Implementing the Optimization Strategy

After an optimization review is completed and recommendations are developed for aparticular site, a strategy should be developed by the RPO review team to facilitateimplementation of the optimization recommendations. The implementation strategy isparticularly important since implementing some recommendations may be contingent onthe results from implementation of other recommendations.

After an optimization re-view is completed and rec-ommendations are devel-oped for a particular site,a strategy should be de-veloped by the RPO reviewteam to facilitate imple-mentation of the optimiza-tion recommendations.



Exhibit 5. Summary of recommendations and resolutions

Performance and ProtectivenessReview Recommendations Base Assessment Regulatory

ConcurrenceType Number Ca Ub Nc RequiredSave time 0 – – – 0Save cost 2 2 – – 2Save time and cost 5 4 0 1 1Increase protectiveness 7 5 0 2 5Improve quality 4 3 0 1 2Otherd 1 1 0 0 0Total 19 15 0 4 10

aC = A favorable response was provided by the base’s program manager. The recommendation will be implemented or

an evaluation will be conducted to assess the potential value of the recommendation prior to deciding on whether

it should be implemented. In some cases, implementation may be one or more years in the future.bU = A response was not provided for this recommendation. The base’s position is unknown. The base and headquarters

should review these recommendations.cN = The response provided indicated that the recommendation would not be implemented.dOther includes organizational items, data presentation methods, management initiatives, and other factors that do

not fall into the more specific categories

Development of an optimization strategy, while based largely on the projectedpotential for implementing each recommendation to improve remedy performance andreduce cost, may also consider challenges that are technical, institutional, financial, andethical in nature.

Implementation Tracking/Tracking of Action Items

The findings and recommendations of an optimization effort should be monitored ortracked to verify the status of implementation, in much the same way as other projectaction items. The what, who, how, when, and expected outcome are the common itemsthat need tracking. In RPO terms, this task generally translates into tracking therecommended action, the individual(s) responsible for approving and actuallyimplementing the action, the recommendation to be accomplished, the estimated oractual implementation date or time frame, and the expected or known outcome (costsavings, time savings, better protectiveness). This type of implementation tracking can bemonitored and updated as frequently as needed, with semiannual updating generallyconsidered the minimum frequency. Exhibit 5 presents an example of a set of trackingmatrices used to track the implementation of some Air Force Real Property Agency(AFRPA) Performance and Protectiveness Review recommendations. As shown, a total of19 recommendations were made at these facilities out of which 15 recommendations weremet with favorable site responses. Only two of these recommendations were onlycost-saving and five were time- and cost-saving recommendations. A majority (11) ofrecommendations were to increase protectiveness and improve quality.



CHALLENGES AND SOLUTIONS IN THE RPO PROCESS

Challenges inherent in RPO include technical, institutional, contractual, and regulatoryissues. Technical challenges are introduced by uncertainties in the performance of aremediation strategy. Institutional challenges result from competing objectives anddifferent goals. Contractual challenges reflect the reality of limited resources such asfinances. Regulatory challenges reflect the differing regulations applicable at sites and howthe program areas can support the RPO implementation. Communication and educationplay a very important role in overcoming intrinsic resistance to the RPO process.Recognizing and addressing challenges facilitates successful outcomes. Therefore, RPOreview teams should include independent, multidisciplinary participants who understandthe challenges and can articulate objective recommendations and perhaps facilitatecompromises.

Technical Challenges and Solutions

Most technical challenges to RPO can be attributed to the uncertainties and variables inthe performance of an engineered system within a dynamic and heterogeneous naturalenvironment. Technical solutions to remediation problems should be based on thescientific method and ideally should include systems engineering design principles andquantitative optimization or decision analysis methods. Existing systems require objectiveevaluation not only of their ability to perform as originally intended, but also of theirability to meet revised goals and objectives. Should the RPO review team conclude thatthe existing system would not meet the revised remediation requirements, the teamshould consider evaluating possible alterations to the existing system, as well as theadoption of alternative technologies. Systems engineering approaches such as failure (orreliability) analyses can be applicable and useful in such cases. Stochastic analyses areespecially useful because they account for inevitable uncertainty regarding theperformance of the engineered system within the environment, and ensure that the designbasis of the engineered system also accommodates those uncertainties.

Technical solutions toremediation problemsshould be based on thescientific method andideally should include sys-tems engineering designprinciples and quantitativeoptimization or decisionanalysis methods.

Institutional Challenges and Solutions

Institutional barriers may hinder the embracing of process optimization. Inertia of theexisting remedial project structure, a lack of formal institutional policies regardingimplementing and tracking optimization, sparse administrative support, poor relationswith stakeholders, and frequent turnover of personnel may prohibit the acceptance of newapproaches.

Many projects have an inherent inertia toward change. In many cases, there arefew—or no—incentives for the project team to revisit the current remedy. Often, thereis no aspect of the overall personnel performance evaluation process that gives credit forRPO-like activities. The performance metrics are more focused on meeting the existingbudget and schedule and avoiding problems rather than on improving performance andefficiency. The project staff may feel that any evaluation of the remedy that results inrecommendations for change is an indictment of their past efforts, and they may resistRPO. Existing systems and entire programs may be entrenched in administrativeprocesses and focused on “bean counting” or graduating sites out of the program.



Unfortunately, there is often no mechanism for programwide initiation, funding, andtracking of RPO at sites covered by such a program.

Management endorsement of RPO and formalization of the process for conducting,funding, and tracking the results of RPO at the overall program level greatly enhances theacceptance of RPO at the project level. This process also requires the development ofspecific RPO performance metrics for staff responsible for each system. Some positiverecognition of successful RPO efforts (through such incentives as awards and cash) willfurther encourage acceptance and improve project staff performance. Resources saved(money and personnel) should be reinvested within the program area. If a team savesresources through RPO process and loses all those resources in the following years’budgets, such a team will not have an incentive to embrace challenging opportunities suchas RPO. Focusing on the efficient use of limited resources across many sites whileimproving protectiveness will help garner support for RPO. Keeping this long-term focuswill help overcome the skepticism some stakeholders have and a reluctance to makenecessary changes to RODs or permits. The use (or continued use) of teaming approachesmay offset loss of institutional knowledge as a personnel change.

It is worth noting that not all facilities are interested in optimizing their correctiveaction systems. After initial remedy construction is complete, some facilities viewcorrective action costs as an annual line-item expenditure and are interested only inachieving a minimal degree of compliance with cleanup requirements with the lowestpossible, predictable annual cost. These facilities will be resistant to the RPO process if itappears likely that additional capital outlay will be required, despite the potential foroverall life-cycle cost savings.

Contractors assume thegreatest amount of riskunder fixed-price contractsbecause they are respon-sible for the costs ofperformance, whereas un-der cost-reimbursable con-tracts, the government as-sumes the majority of risk.

Contractual Challenges and Solutions

Contractors may perceive that process optimization will result in a loss of revenue;particularly if their system is modified to reduce operating costs or is replaced with a moreeffective remediation alternative. However, contracting options are available that canalign the contractor’s financial incentives with the goals of the remediation program.Contracting strategies include using performance-based contracts when feasible andestablishing a set of performance measures directly tied to the site closure strategy. Inaddition, contractors should recognize that their ability to provide an optimized approachto site closure will result in a favorable reputation, giving them an advantage in thecompetition for new contracts based on superior past performance.

Fixed-price and cost-reimbursable contracts are the types of contracts most widelyused for environmental remediation. Contractors assume the greatest amount of riskunder fixed-price contracts because they are responsible for the costs of performance,whereas under cost-reimbursable contracts, the government assumes the majority of risk.A fixed-price performance-based contract provides an incentive to the contractor toconduct operations effectively and efficiently and to manage costs. Cost-reimbursablecontracts are appropriate during the first few months of operation (start-up, shakedown,and optimization of new remedial systems). After the initial start-up, fixed-price contractsare preferable during the remedial actions if the project scope is well defined, there arefew unknowns, and it is unlikely that the scope will change. Such performance-basedcontracts are becoming popular with many agencies and industry entities as they areshowing promise in reaching remediation goals within predefined time frames. However,



for nonroutine maintenance and expendable items (such as carbon and polymer), acost-reimbursable contract can be used.

Regulatory Challenges and Solutions

The existence of one or more regulatory frameworks, the involvement of variousagencies, and potentially changing regulations have an influence on the RPO process andrequire an integrated approach to optimization. Different regulatory programs may covera single facility or site, and often state, local, and federal agencies are involved.Disagreement among and within agencies may inhibit the ratification or implementation ofa proposed RPO plan, particularly when the parties consider overturning agreed-upondecisions. Regulations may change over time, such as new contaminants being added tothe regulated list or MCLs being revised upward or downward. In addition, whileregulatory standards are commonly used to establish cleanup goals, more recently,risk-based goals have gained greater acceptance from the regulatory community. Roomfor flexibility by regulatory stakeholders while keeping within the governingenvironmental regulations will facilitate the optimization process.

The existence of one ormore regulatory frame-works, the involvement ofvarious agencies, and po-tentially changing regula-tions have an influence onthe RPO process and re-quire an integrated ap-proach to optimization.

Educating various parties on the benefits of RPO is necessary. Incorporating RPOinto established regulatory and other review programs would be a logical interface.Opportunities include annual program reviews, CERCLA five-year reviews, and RCRApermit modifications. These reviews meet regulatory requirements to present cost andperformance data, provide an opportunity to discuss remedial progress, and identifyopportunities to optimize the remedial systems. The routine involvement of each agencyin site evaluation will result in consensus conclusions and recommendations for changesand improvements.

STAKEHOLDER PARTICIPATION

Lastly, one of the most important factors in a successful remediation and RPO process isproper buy-in and participation of all the stakeholders involved. The ITRC RPO teamrecognizes and emphasizes the importance of stakeholder involvement in the remediationprocess. Remediation process optimization is a proven process that is used to evaluate andimprove the effectiveness of a remediation system while maintaining protectiveness and isdesigned to meet the remediation goals in the shortest time with proven practicalsolutions. The RPO process is a dynamic tool that should be regularly implemented toensure that the site’s remediation goals are met expeditiously and cost-effectively.Continuous improvement in the remediation process requires stakeholder support andconcurrence.

The technologies, processes, and regulatory environment for remediation areevolving. The RPO process is a valuable tool that should be used frequently to assessremediation projects to ensure the remediation objectives are met in a timely andcost-effective manner. Therefore, appropriate stakeholder involvement will enhance theimplementation of the RPO process and increase public acceptance of proven approachesto meeting the final remediation goals.



SUMMARY AND CONCLUSIONS

This article explains what an RPO review is and how it is conducted at a typicalcontaminated site. After several Internet and classroom-based trainings the ITRC team hasoffered, the RPO process has come a long way—from being an innovative technique to awidely accepted (some times even routinely conducted) process in the last few years.Following the feedback from the presentations, the ITRC RPO team has obtained a set offive fact sheets published in 2006 to expound on some of the topics of interest forremediation practitioners.

An RPO evaluation can benefit not only large facilities with multiple sites, but alsosmall sites, such as UST sites. Depending on the number of systems/components inoperation at a site, an RPO can be conducted facility- or complexwide or only at a singlesite within the facility. Although it is never too early to consider optimization at a site,after the system is in operation for a year or two, the time is appropriate for an RPO.Depending on the needs at a site, the RPO review can be conducted as a one-time processor it can be conducted several times at the same site. Although, time and money savingsare possible at various sites where RPOs are conducted, it is important to note thatsometimes, additional expenditures are necessary to conduct RPO reviews that may resultin additional monitoring before remediation goals can be reached at a site. Also, althoughit may appear that RPO can be most economical at a contaminated site with groundwater

TABLE OF CONTENTS

1 INTRODUCTION

1.1 Remedial Process Optimization Review1.2 RPO Strategy Components1.3 Description of the RPO Review

2 RPO PROJECT TASKS

2.1 Tasks2.2 Applicable or Relevant and Appropriate Requirements Identification2.3 Data Needs Identification2.4 RPO Review Action Plan2.5 Optimization Decision Criteria2.6 Identification of RPO Candidates2.7 Remedial Systems Best Optimized

3 RPO REVIEW LOGISTICS

3.1 RPO Team3.2 RPO Agenda3.3 RPO Report3.4 Project Schedule

4 SITE-SPECIFIC INFORMATION

4.1 Site History and Setting4.2 Internet Resources4.3 Existing Systems Information

LIST OF REFERENCES

Exhibit 6. An example work plan table of contents for an RPO review proposal



OPTIMIZATION CASE STUDY EXAMPLE

Site Name: MacGillis & Gibbs Superfund Site

Site Location (City, State, Zip Code): New Brighton, MN 55112

Funding Agency or Party for Site Remediation: US EPA Region V

Funding Agency or Party for Optimization Effort: US EPA Technology Innovation Office

Agency, Party, or Contractor Performing Optimization: GeoTrans, Inc., and U.S. Army Corps of Engineers

Start/Finish Dates of Optimization Effort:Site Visit—June 2000 Final Report—February 2001 Follow-up calls to track implementation—January 2002 and September 2003

Optimization Process Used (if Specific Process Used): Remedial system evaluation process developed by US ACE and modified by GeoTrans

Cost of Optimization Effort: • $25,000 for the Remediation System Evaluation (RSE) • $2,500 per year for a period of two years for following up and tracking

implementation of recommendations

Total Potential Cost Savings, if Any: $225,000 per year

Site Information: Primary Contaminants of Concern:• Pentachlorophenol• PAHs• Dioxin• Chromium • Arsenic

Remediation Systems:• OU2 pump-and-treat system • OU3 pump-and-treat system

Total Flow Rate: Approximately 50 gpm total • OU2 less than 1 gpm from one well • OU3 under 50 gpm from 12 wells

Exhibit 7. An example of an actual RPO case study conducted at a Superfund site

(Remediation System Evaluation [RSE] is used as a synonym for RPO in this example)

pump-and-treat as the primary cleanup technology in operation, RPO can be applied atalmost all sites with many different technologies.

It is important to take the opportunity to examine all aspects of a site during an RPOreview. An RPO might be directed at the long-term pump-and-treat system at a site.However, there may be several areas of concern at a site at different phases ofdevelopment in the remedial process. By expanding the RPO and examining all aspects of



Treatment Processes: OU2 and OU3 both include an oil/water separator, fixed film bioreactor system (by BioTrol), clarifier, bag filters, and GAC with dischargto the publicly owned treatment works (POTW)

Total Number of Monitoring Wells Sampled: • None at the time of the RSE • Eight extraction wells sampled quarterly

Total Annual Cost for Remediation:• Estimated by site team as $535,000 during RSE (excludes monitoring

and other costs) • Actual costs during 2002 were ~$770,000 and reflect remedy costs

prior to implementation of RSE recommendations

Year Remediation System(s) Began Operation:OU2 – March 1998 OU3 – March 1999

Optimization Effort: Treatment Optimization: Briefly describe recommendations for changes in treatment processes (including discharge options), costs for implementation, and potential cost savings.• discontinue operation of the OU2 system and combine the flows

to the OU3 system ($50,000 to implement and $140,000 per year potential savings)

• modify the treatment system by eliminating the bioreactor and using the GAC as the main treatment ($25,000 to implement and $55,500 per year potential savings)

• combine POTW discharge points to reduce analytical costs ($30,000 to implement and $30,000 per year potential savings

Status of implementation of recommendations: • The OU2 treatment system was shut down and was being

dismantled in 2003. • The OU3 bioreactor operating costs have been reduced since

preheating the influent, adding polymer, and adjusting pH were determined to not be necessary. Therefore, the bioreactor has been kept and the GAC bypassed.

• The effluent sampling frequency has been reduced resulting in cost savings of approximately $100,000 per year. The POTW discharge points have not been consolidated.

• Operating costs have been decreased by $115,000 despite an increase in utility rates, and in the extraction rate to improve capture, and regular capture zone evaluations (see below).

Exhibit 7. Continued

a site, a more comprehensive CSM can be developed, and the corresponding exit strategycan anticipate the needs of all areas of concern.

An example of a typical RPO work plan is shown in Exhibit 6 with an RPO case studypresented in Exhibit 7. The detailed work plan and several other example case studies areprovided as appendices in the RPO guidance document (ITRC, 2004).



Subsurface Performance Optimization: Briefly describe recommendations for changes in subsurface extraction or in situ treatment systems to enhance performance or protectiveness, costs for implementation, and potential cost savings: • The RSE report recommended that the site develop a target capture zone and

analyze data to determine if the capture is achieved ($30,000 to implement and $5,000 per year in continuing evaluation costs).

Status of implementation of recommendations: The site team performed capture zone analysis and added two additional extraction wells to provide capture of the target zone.

Monitoring Program Optimization: Briefly describe recommendations for changes in monitoring program and process monitoring, costs for implementation, and potential cost savings: • The RSE recommended that a monitoring program be developed ($40,000 to

implement plus no additional annual costs since a plan would have been developed in any event)

Status of implementation of recommendations: The site team has developed a program that includes annual sampling and analysis of 55 monitoring wells. Annual costs are approximately $90,000 per year

Summary:The pump-and-treat system aims to contain the groundwater plume, remove NAPL, and restore the aquifer. Actual annual O&M costs prior to implementing RSE recommendations were approximately $770,000 per year. RSE recommendations have been implemented to evaluate capture, improve containment, simplify the treatment system, and reduce effluent monitoring. Despite increased pumping, enhanced data evaluation (i.e., periodic capture zone analyses), and increased utility rates, the annual costs for O&M have decreased to approximately $655,000 per year.

Exhibit 7. Continued

In summary, RPO is a tool of best management practice status that can be used tomore effectively conduct site remediation activities. The process can be used at anytimefor any phase of site cleanup. No site is too small to benefit from the RPO process. It canbe initiated from the operator level at a specific site or established at the highestmanagement levels. The key is to perform the RPO, follow up with an implementationand tracking plan and then, if warranted, conduct a follow-up RPO in the future.

REFERENCES

American Society of Testing and Materials. (2003). Standard classification for life-cycle environmental work

elements—Environmental cost element structure. E2150-02. West Conshohocken, PA: Author.

Interstate Technology and Regulatory Council (ITRC). (2004). Remediation process optimization: Identifying

opportunities for enhanced and more efficient site remediation. TechReg Document. Washington, DC:

Author.

Interstate Technology and Regulatory Council (ITRC). (2006). A series of five technology overview documents

on: life cycle cost analysis, exit strategy, above ground treatment technologies, data management and

visualization techniques, and performance-based management. Washington, DC: Author.



Shultz, L. I., & Weber, S. F. (2003). Guide to computation and reporting the life-cycle cost of environmental

management projects. Gaithersburg, MD: U.S. Department of Commerce, Technology Administration,

National Institute of Standards and Technology.

U.S. Environmental Protection Agency (US EPA). (2000). A guide to developing and documenting cost

estimates during the feasibility study. EPA 540-R-00-002. OSWER 9355.0-75. Washington, DC: Author.

Sriram Madabhushi has been a geologist/project manager with the South Carolina Department of Health

and Environmental Control since 1992, working in underground storage tank, CERCLA, and RCRA program areas.

His interests and contributions are in risk-based corrective action, performance-based management, statistical

decision-making techniques in remedy selection, optimization of remediation technologies, and groundwater

fate and transport modeling. He earned his MS from the Indian Institute of Technology, Kharagpur, and a BS

from Andhra University.

Tom O’Neill is a section chief with the New Jersey Department of Environmental Protection’s (NJDEP’s)

Site Remediation and Waste Management Program. He joined the NJDEP in 1983 as an on scene coordinator

overseeing a wide variety of publicly funded (state funds and Superfund) removal actions and planned site

remediations. His prior work includes design engineering with The Lummus Company, designing pollution

control (air, water, and noise) systems for chemical and petrochemical facilities. He earned an MS from the New

Jersey Institute of Technology–Newark College of Engineering and a BS in environmental science from Rutgers

University–Cook College.


Remediation process optimization: A status report

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