2018216 Environmental Protection Agency Handbook 98 Ch18

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Chapter 1Introduction

1.1 Purpose

Maintaining public health protection at water supplysystems has become more challenging in recentyears with the resistance of some pathogens todisinfection using chlorination and an increase in theimmuno-compromised population (e.g., people withHIV, organ transplant patients, the elderly). Also, asevidenced by recent outbreaks, compliance with the1989 Surface Water Treatment Rule (SWTR) doesnot always assure maximum protection of the publicfrom waterborne disease (1). Based on this aware-ness, the U.S. Environmental Protection Agency(USEPA) is developing regulations to control con-tamination from microbial pathogens in drinking waterwhile concurrently addressing other concerns such

as disinfection by-products (2,3). These new andinterrelated regulations are moving the water supplyindustry toward meeting increasingly more stringentwater treatment requirements.

Research and field work results support optimizingparticle removal from water treatment facilities tomaximize public health protection from microbial con-tamination (4,5,6). Since 1988 the Composite Cor-rection Program (CCP) has been developed anddemonstrated as a method of optimizing surfacewater treatment plant performance with respect toprotection from microbial pathogens in the United

States and Canada (7,8). The approach is based onestablishing effective use of the available water treat-ment process barriers against passage of particles tothe finished water.

Specific performance goals are used by the CCPapproach to define optimum performance for keytreatment process barriers such as sedimentation,filtration, and disinfection. These include a maximumindividual sedimentation basin effluent turbidity goalof less than 2 nephelometric turbidity units (NTUs) toassure that the integrity of this barrier is consistentlymaintained and to provide a low particle loading to

the filters. For the filtration barrier, optimum per-formance has been described as individual filter efflu-ent turbidities of less than 0.1 NTU with a maximumpost backwash spike to 0.3 NTU and returning toless than 0.1 NTU in less than 15 minutes. The dis-infection goal has been based on achieving the loginactivation requirement for Giardia and/or virusesdescribed in the SWTR guidance (9).

This handbook is an updated version of the USEPAHandbook: Optimizing Water Treatment Plant Per-

formance Using the Composite Correction Programpublished in 1991 (7). It is intended to serve as aresource document for optimizing the performance ofexisting surface water treatment facilities to provideprotection from microbial contamination.

1.2 Background

1.2.1 Wastewater Treatment Compliance

The CCP approach was initially developed toaddress compliance problems at wastewatertreatment facilities that were constructed in the late1960s and 1970s. A survey involving over onehundred facilities was conducted to identify thereasons for this non-compliance (10,11,12). Thesurvey revealed that operations and maintenancefactors were frequently identified as limiting plantperformance, but also disclosed that administrativeand design factors were contributing limitations.Most importantly, each plant evaluated had a uniquelist of factors limiting performance.

Based on these findings, an approach was devel-oped to identify and address performance limitationsat an individual facility and to obtain improvedperformance. Significant success was achieved inimproving performance at many wastewater

treatment facilities without major capitalimprovements (13). Ultimately, a handbook wasdeveloped that formalized the evaluation andcorrection procedures (14). The formalized approachwas defined as the Composite Correction Program

(CCP), and it consists of two componentsaComprehensive Performance Evaluation (CPE) andComprehensive Technical Assistance (CTA). As apoint of clarification, the technical assistance phasewas initially referred to as a Composite CorrectionProgram; however, the name of this phase waschanged to Comprehensive Technical Assistance tobetter differentiate the two phases. A CPE is a

thorough review and analysis of a plants perform-ance-based capabilities and associatedadministrative, operation, and


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maintenance practices. It is conducted to identifyfactors that may be adversely impacting a plantsability to achieve permit compliance without majorcapital improvements. A CTA is the performanceimprovement phase that is implemented if the CPEresults indicate improved performance potential.During the CTA phase, identified plant-specific fac-tors are systematically addressed and eliminated.

The wastewater CCP handbook was updated in 1989to include specific low cost modifications that couldbe used to optimize an existing facilitys performance(15). An expert system (POTW Expert) was alsodeveloped to supplement the handbook (16).

1.2.2 Water Treatment Optimization

Based on the state of Montanas successful use ofthe CCP approach for improving compliance of theirmechanical wastewater treatment facilities, state

personnel evaluated the feasibility of using the CCPto optimize the performance of small surface watertreatment facilities. With financial assistance fromUSEPA Region 8, nine CPEs and three CTAs werecompleted from April 1988 until September 1990.Through these efforts, each of the existing facilitieswhere CTAs were implemented showed dramaticimprovements in the quality of finished water tur-bidity. Additionally, improved performance wasachieved at three plants where only the evaluationphase (CPE) of the program was completed (17).The encouraging results from Montanas adoption ofthe CCP approach to surface water treatment plants

led to the USEPAs Office of Ground Water andDrinking Water involvement with the program in1989.

USEPA decided to further develop and demonstrateuse of the CCP approach as it applied to compliancewith drinking water regulations to ensure its applica-bility nation-wide. In pursuit of this goal, a coopera-tive project was initiated between USEPAs Office ofGround Water and Drinking Water, TechnicalSupport Center (TSC) and Office of Research andDevelopment, Technology Transfer and SupportDivision, National Risk Management Research Labo-

ratory (NRMRL). This project provided resources to:conduct an additional twelve CPEs in the states ofOhio, Kentucky, West Virginia, Maryland, Montana,Vermont, and Pennsylvania; prepare a summaryreport (8); and develop a water CCP Handbook (7).

Following these initial efforts, work continued,through a cooperative agreement between TSC andthe University of Cincinnati, on further refinement anddevelopment of the CCP approach. Formal effortswere implemented to incorporate the CCP into state

programs. It was anticipated that application of theCCP by state regulatory personnel would achievedesired performance levels with a minimum financialimpact on the utilities in their jurisdiction. Pilot pro-grams were implemented in eight states (WestVirginia, Massachusetts, Maryland, Rhode Island,Kentucky, Pennsylvania, Texas, and Colorado) whichfocused on developing CPE capability for state staff.

A progressive training process was developed withineach state. The training process included the com-pletion of a seminar followed by three CPEs con-ducted by a state core team that was facilitated byUSEPA and Process Applications, Inc. Similar pilotprograms were also completed in USEPA Regions 6and 9. Typically, state regulatory staff selected theCPE candidate plants based on their perception ofthe plants inability to meet the SWTR turbidityrequirements.

The progressive training approach proved to be suc-cessful; however, other issues and challenges

related to implementation within the existing stateregulatory program structure became apparent. Asthe state pilot programs progressed, thesechallenges to implementation became known col-lectively as institutional barriers. The impact ofinstitutional barriers on state-wide optimization effortsis discussed further in Chapter 3.

1.2.3 Broad-Scale Application of CCPConcepts

The optimization concepts included within the CCP

approach have been expanded to a variety of waterindustry and regulatory activities. A partial list ofcurrent optimization efforts that utilize components ofthe CCP is described below.

The states of Alabama, Georgia, Kentucky, andSouth Carolina, in cooperation with EPA Region4, are currently pursuing a multi-state effort thatfocuses on optimization of their surface watertreatment facilities through a pilot program basedon the application of the CCP concepts and tools.

The Partnership for Safe Water is a voluntary

program for enhancing water treatment to


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provide higher quality drinking water. Organizationsinvolved in the Partnership include the U.S. Envi-ronmental Protection Agency, American Water Works

Association, Association of Metropolitan WaterAgencies, National Association of Water Companies,Association of State Drinking Water Administrators,and the American Water Works AssociationResearch Foundation. The Partnership utilized the

CCP as the basis of its Phase III comprehensivewater treatment self-assessment (18). Use of theCCP is also being considered for the Phase IV thirdparty assessment of participating utilities. As ofMay 1998, 217 water utilities serving nearly 90 millionpeople are participating in the Partnership for SafeWater.

In 1996 the American Water Works AssociationResearch Foundation conducted an optimizationworkshop with national water quality and treat-ment experts from throughout the industry. As aresult of this workshop, a self-assessment hand-

book was published by AWWARF (19). Thishandbook, which follows the CCP approach, isintended to be a resource for water utilities thatchoose to conduct a self-assessment to improveperformance.

1.3 Scope

Since publication of the predecessor of this hand-book in 1991, several modifications have been madeto the CCP and its use for optimizing surface watertreatment plants. In addition, other complementary

drinking water optimization activities (e.g., Partner-ship for Safe Water) have developed and continue tohave positive impacts in this area. The purpose ofthis handbook update is to incorporate new informa-tion and to integrate the other complementary pro-grams.

1.3.1 Update of the CCP Approach andImplementation

Experience gained from over 70 CPEs and 9 CTAsprovides the basis for updating the CCP approach

presented in this handbook. In addition, eight statepilot programs have provided the basis for the area-wide application of the CCP. Significant additionsand modifications to the CCP included in this hand-book are:

An expanded discussion of the relationshipbetween optimized performance and publichealth protection.

An expanded definition of optimized performancegoals for microbial contaminant protection.

Considerations for selection of CPE and CTAcandidates.

Clarification on CCP terminology.

Description and use of the Partnership for SafeWater software for compiling and analyzing tur-bidity data.

Updated process criteria for completing the majorunit process evaluation.

An updated database of completed CPEs andCTAs and a summary of typical factors foundlimiting performance.

Streamlined forms for collection of field data.

1.3.2 Support for Future Regulations

The initial CCP handbook focused on meeting therequirements of the Surface Water Treatment Rule(SWTR) (20). As the challenges of protecting thepublic health from microbial contamination becamemore paramount, the emphasis was shifted from theSWTR requirements to achieving optimized perform-ance goals.

Pursuant to the requirements under the 1996

Amendments to the Safe Drinking Water Act(SDWA), the USEPA is developing interrelatedregulations to control microbial pathogens anddisinfectants/disinfection byproducts in drinkingwater, collectively known as the microbial/disinfectionbyproducts (M/DBP) rules. The 1996 Amendment tothe SDWA set a deadline for promulgation of theInterim Enhanced Surface Water Treatment Rule(IESWTR) of November 1998. USEPAs Notice ofData Availability (3) indicates that this rule will includea revised finished water turbidity requirement of 0.3NTU, new individual filter monitoring requirements,and requirements for states to have authority to


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require the conduct of CCPs for water utilities thatexperience difficulties in meeting the turbidityrequirements of the rule. This handbook is intendedto provide a technical resource to support theimplementation of the IESWTR.

1.3.3 Technical Resource for the Partnershipfor Safe Water

This updated handbook is also intended to comple-ment and enhance the existing Partnership for SafeWater documentation and program activities. Inaddition to supporting the ongoing Phase III self-assessment activities, the handbook will also supportthe anticipated Phase IV activities. A possiblePhase IV approach could involve an independentthird party review of a utility using the CCP format.This final step in the Partnership process ensuresthat some of the potential limitations of self-assessment (e.g., difficulty in identifying operational

and administrative factors) are not overlooked.

1.3.4 Considerations for Total SystemOptimization

Although this handbook is intended to be a technicalresource for surface water treatment facilities to pur-sue optimized performance for protection againstmicrobial contamination, it is recognized that as theregulations change and optimum performance is pur-sued, the focus of optimization activities will expandto other parameters. Anticipated future areas for

optimization include source water protection, disin-fection by-products, corrosion control, groundwaterdisinfection, and distribution system water quality.This expanded scope is called total system optimiza-tion. Minor additions are included in this handbook toaddress some of these areas; however, futurehandbook modifications or additional handbooks areenvisioned to more thoroughly address total systemoptimization concepts and topics.

1.4 Using the Manual

The primary intended users of this handbook includeregulators (e.g., federal and state agency personnel)and non-regulators (e.g., utility personnel and con-sultants). To facilitate the use of this handbook,information has been separated into the followingchapters:

Chapter 1 - Introduction

Chapter 2 - Protection of Public Health fromMicrobial Pathogens

Chapter 3 - Assessing Composite Correc-tion Program Application

Chapter 4 - Comprehensive PerformanceEvaluations

Chapter 5 - Comprehensive TechnicalAssistance

Chapter 6 - Findings From Field Work

Chapter 7 - Current and Future RegulationImpacts on Optimization

Chapter 8 - Other CCP Considerations

Table 1-1 provides guidance on where specific user

groups can locate within this handbook informationthat is considered pertinent to their unique interest orintended use.

1.5 References

When an NTIS number is cited in a reference, thatreference is available from:

National Technical Information Service5285 Port Royal RoadSpringfield, VA 22161(703) 487-4650

1. Kramer, M.H., et al. 1996. Waterborne Disease:1993 and 1994. Journal AWWA, 88(3):66.

2. USEPA. 1997. National Primary Drinking WaterRegulations: Disinfectants and DisinfectionByproducts; Notice of Data Availability; ProposedRule. Fed. Reg., 62:212:59338 (November 3,1997).

3. USEPA. 1997. National Primary Drinking WaterRegulations: Interim Enhanced Surface WaterTreatment Rule Notice of Data Availability;Proposed Rule. Fed. Reg., 62:212:59486(November 3, 1997).

Table 1-1. Information Pertinent to Specific User Groups


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User Purpose Chapter Source

USEPA/StateRegulatoryPersonnel

Assess application of the CCP as part of an area-wideoptimization strategy

Chapter 3

Identify priority plants for CCP application Chapter 3

Review/learn the CPE protocol Chapter 4

Review/learn the CTA protocol Chapter 5

Review CCP database for common factors limitingperformance

Chapter 6

Review quality control criteria for assessment of thirdparty CCPs

Chapter 8

UtilityPersonnel

Utilize the CCP as a self-assessment resource Chapters4 & 5

Assess capabilities of CCP providers Chapter 8

Consultants/Peer Assessment

Review/learn the CPE protocol Chapter 4

Team Members Review/learn the CTA protocol Chapter 5

Review CCP database for common factors limitingperformance

Chapter 6

4. Patania, N.L., et al. 1996. Optimization of Filtra-tion for Cyst Removal. AWWARF, Denver, CO.

5. Nieminski, E.C., et al. 1995. Removing Giardiaand Cryptosporidium by Conventional Treatmentand Direct Filtration. Journal AWWA, 87(9):96.

6. Consonery, P.J., et al. 1996. Evaluating andOptimizing Surface Water Treatment Plants:How Good is Good Enough? Paper presentedat

AWWA Water Quality Technology Conference,Boston, MA.

7. Renner, R.C., B.A. Hegg, J.H. Bender, and E.M.

Bissonette. 1991. Optimizing Water TreatmentPlant Performance Using the Composite Correc-tion Program. EPA/625/6-91/027, USEPACenter for Environmental Research Information,Cincinnati, OH.

8. Renner, R.C., B.A. Hegg, and J.H. Bender.1990. Summary Report: Optimizing WaterTreatment Plant Performance With the Com-posite Correction Program. EPA 625/8-90/017,

USEPA Center for Environmental ResearchInformation, Cincinnati, OH.

9. Guidance Manual for Compliance With the Filtra-tion and Disinfection Requirements for PublicWater Systems Using Surface Water Sources.1989. NTIS No. PB-90148016, USEPA,Cincinnati, OH.

10. Hegg, B.A., K.L. Rakness, and J.R. Schultz.1979. Evaluation of Operation and MaintenanceFactors Limiting Municipal WastewaterTreatment Plant Performance. EPA 600/2-79-034, NTIS No. PB-300331, USEPA, MunicipalEnvironmental Research Laboratory, Cincinnati,

OH.

11. Gray, A.C., Jr., P.E. Paul, and H.D. Roberts.1979. Evaluation of Operation and MaintenanceFactors Limiting Biological WastewaterTreatment Plant Performance. EPA 600/2-79-087, NTIS No. PB-297491, USEPA, MunicipalEnvironmental Research Laboratory, Cincinnati,OH.


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12. Hegg, B.A., K.L. Rakness, J.R. Schultz, and L.D.DeMers. 1980. Evaluation of Operation andMaintenance Factors Limiting Municipal Waste-water Treatment Plant Performance - Phase II.EPA 600/2-80-129, NTIS No. PB-81-112864,USEPA, Municipal Environmental ResearchLaboratory, Cincinnati, OH.

13. Hegg, B.A., K.L. Rakness, and J.R. Schultz.1979. A Demonstrated Approach for ImprovingPerformance and Reliability of Biological Waste-water Treatment Plants. EPA 600/2-79-035,NTIS No. PB-300476, USEPA, Cincinnati, OH.

14. Hegg, B.A., J.R. Schultz, and K.L. Rakness.1984. EPA Handbook: Improving POTW Per-formance Using the Composite Correction Pro-gram Approach. EPA 625/6-84-008, NTIS No.PB-88184007, USEPA Center for EnvironmentalResearch Information, Cincinnati, OH.

15. Hegg. B.A., L.D. DeMers, and J.B. Barber. 1989.EPA Technology Transfer Handbook:Retrofitting POTWs. EPA 625/6-89-020, NTISNo. PB-90182478, USEPA Center for Envi-ronmental Research Information, Cincinnati, OH.

16. Publicly Owned Treatment Works Expert UsersGuide and Software. 1990. Eastern ResearchGroup, Inc. and Process Applications, Inc. forUSEPA Center for Environmental ResearchInformation, Cincinnati, OH.

17. Renner, R.C., B.A. Hegg, and D.L. Fraser. 1989.Demonstration of the Comprehensive Perform-

ance Evaluation Technique to Assess MontanaSurface Water Treatment Plants. Presented atthe 4th Annual ASDWA Conference, Tucson, AZ.

18. Bender, J.H., R.C. Renner, B.A. Hegg, E.M.Bissonette, and R. Lieberman. 1995. Partner-ship for Safe Water Voluntary Water TreatmentPlant Performance Improvement Program Self-

Assessment Procedures. USEPA, AWWA,AWWARF, Association of Metropolitan WaterAgencies, Association of State Drinking WaterAdministrators, and National Association ofWater Companies.

19. Renner, R.C., and B.A. Hegg. 1997. Self-Assessment Guide for Surface Water TreatmentPlant Optimization. AWWARF, Denver, CO.

20. USEPA. 1989. Surface Water Treatment Rule.Fed. Reg., 54:124:27486 (June 29, 1989).


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Chapter 2Protection of Public Health From Microbial Pathogens

2.1 Background

One of the major objectives of water supply systemsis to provide consumers with drinking water that issufficiently free of microbial pathogens to preventwaterborne disease. Water supply systems canachieve this level of public health protection by pro-viding treatment to assure that pathogens found inthe raw water supply are removed or inactivated.The relationship between optimized water treatmentplant performance and protection of public healthfrom microbial pathogens is presented in thischapter.

2.2 Waterborne Disease History

Several well documented disease outbreaks thatwere associated with the use of untreated surfacewater, contaminated well water, treatment plantdeficiencies, and contaminated distribution systemshave occurred over the past 20 years. During thisperiod the most common suspected causes ofwaterborne disease outbreaks were the protozoanparasites Giardia lamblia and Cryptosporidium

parvum (1). These parasites exist in the environmentin an encysted form where the infectious material isencapsulated such that they are resistant toinactivation by commonly used disinfectants. These

parasites are transmitted to their hosts by ingestionof cysts that have been excreted in the feces ofinfected humans or animals. Infection can occurthrough ingestion of fecally contaminated water orfood or contact with fecally contaminated surfaces.Recent studies have indicated that these parasitesare routinely detected in surface water suppliesthroughout North America (2,3,4). They can entersurface water supplies through natural runoff,wastewater treatment discharges, and combinedsewer overflows.

A recent review of waterborne disease in the U.S.

during the period 1993 through 1994 identified 30disease outbreaks associated with drinking water.The outbreaks caused over 400,000 people tobecome illthe majority from a 1993 outbreak inMilwaukee. Twenty-two of the outbreaks wereknown or suspected to be associated with infectiousagents and eight with chemical contaminants. Giar-

dia orCryptosporidium was identified as the causa-tive agent for 10 of the outbreaks, and six of thesesystems were associated with a surface water

source. All six systems provided chlorination, andfour also provided filtration. In the filtered systems,deficiencies in the distribution system were identifiedfor one outbreak, inadequate filtration for one, and noapparent deficiencies were identified in two cases(1).

Cryptosporidium presents a unique challenge to thedrinking water industry because of its resistance tochlorination and its small size, making it difficult toremove by filtration. Cryptosporidiosis is the diar-rheal illness in humans caused by Cryptosporidium

parvum. Cryptosporidiosis outbreaks from surface

water supplies have been documented in the UnitedStates, Canada and Great Britain (5,6,7). A sum-mary of U.S. outbreaks associated with surface watersupplies is shown in Table 2-1. Five of the outbreakswere associated with filtered drinking waters. Threesystems (Carroll, Jackson - Talent, and Milwaukee)were experiencing operational deficiencies and highfinished water turbidities at the time of the outbreaks.

All three plants utilized conventional treatmentprocesses that included rapid mix, flocculation,sedimentation, and filtration. The Clark Countyoutbreak was the only outbreak associated with afiltered drinking water for which no apparent

treatment deficiencies were noted. All five systemswere in compliance with the federal drinking waterregulations in effect at that time.

Recent research has shown that free chlorine andmonochloramine provide minimal disinfection ofCryptosporidium oocysts at the dosage and detentiontime conditions found at most treatment facilities (8).Disinfection requirements based on CT in the 1989SWTR guidance were developed solely on inactiva-tion ofGiardia lamblia cysts. Research conducted byFinch (9) showed approximately 0.2 log or less inac-tivation of Cryptosporidium when free chlorine was

used alone (5 to 15 mg/L @ 60 to 240 min.). Mono-chloramine was slightly more effective than free chlo-rine. Inactivation ofCryptosporidium through the useof stronger disinfectants (e.g., ozone, chlorine diox-ide) and combined disinfectants is currently beinginvestigated by the water industry and research insti-tutions.

Table 2-1. U.S. Outbreaks of Cryptosporidiosis in Surface Water Supplies (5)

Location Year Type of System EstimatedNumber of


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Cases

Bernalillo County, New Mexico 1986 Untreated surface water supply 78

Carroll County, Georgia 1987 Treated surface water supply 13,000

Jackson County, Oregon 1992 Medford chlorinated spring

Talent treated surface water

15,000

Milwaukee County, Wisconsin 1993 Treated surface water supply 403,000

Cook County, Minnesota 1993 Treated surface water supply 27

Clark County, Nevada 1994 Treated surface water supply 78

The recent incidence of waterborne disease associ-ated with protozoan parasites and the resistance ofsome pathogens to conventional disinfection

presents a challenge to the water industry. Use of asingle barrier, such as disinfection alone, or operationof a conventional treatment plant that had not beenoptimized has contributed to several diseaseoutbreaks. For surface supplied filtration plants,minimizing consumers risk from microbial pathogenswill require a proactive approach to water treatment,including plant optimization.

2.3 Relationship Between Optimized

Performance and Public Health

Protection

2.3.1 Multiple Barrier Strategy

Microbial pathogens, including protozoan parasites,bacteria, and viruses, can be physically removed asparticles in flocculation, sedimentation, and filtrationtreatment processes or inactivated in disinfectionprocesses. Consequently, the level of protectionachieved in a water system can be increased byoptimizing the particle removal processes in a systemand by proper operation of the disinfectionprocesses. In a conventional plant, the coagulationstep is used to develop particles that can be

physically removed by sedimentation and filtrationprocesses. Effective use of these processes as part

of a multiple barrier strategy for microbial protectionrepresents an operational approach for watersystems that choose to optimize performance. This

strategy is also being proposed as a method foraddressing Cryptosporidium in the Interim EnhancedSurface Water Treatment Rule (10).

Particle removal through a water treatment processcan be monitored and assessed by various methodsincluding turbidity, particle counting, and microscopicparticulate analysis (MPA). An increasing number ofwater systems treating a surface water supply haveturbidimeters installed to monitor turbidity at variouslocations throughout the process. Some systems aresupplementing turbidity monitoring with particlecounting and microscopic particulate analysis. How-

ever, because turbidity monitoring is the most com-mon method of assessing particle removal in surfacewater systems, performance goals based on thisparameter have been developed for the CCP todefine optimized system performance.

The role of multiple treatment barriers in optimizingwater treatment for protection from microbial patho-gens and the associated performance goals areshown in Figure 2-1. Despite variability in sourcewater quality, surface water treatment plants mustproduce consistently high quality finished water. Tomeet this objective, each treat-ment process must

consistently produce treated water of a specificquality. To this end,


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Figure 2-1. Multiple barrier strategy for microbial contaminant protection.

Flocculation/Sedim entation

Barrier Filtration

Barrier

Disinfection

Barrier

Disinfectant

Addition

Coagulant

Addition

Turbidity

Goal

< 2 NTU

Turbidity

Goal

< 0.1 NTU

Variable

Quality

Source

W ater

Finished

W ater

Achieve

Inactivation

Goal

performance goals have been established for each of

the treatment barriers in a plant.

When plants include a sedimentation process, themaximum sedimentation basin effluent turbidity goalof less than 2 NTU is used to define optimumprocess performance. A sedimentation performancegoal ensures the integrity of this barrier and providesa consistent particle loading to the filtration process.With respect to optimum particle removal for thefiltration process, the optimum performance goal isdefined as achieving individual filter effluentturbidities of less than 0.1 NTU.

The performance of the disinfection barrier is basedon the log inactivation requirement for Giardia andvirus, as established by the Surface Water TreatmentRule guidance manual (11). This document providestables of the required CT (i.e., disinfectant concentra-tion (C) times the time (T) that the disinfectant mustbe in contact with the water) to achieve differentlevels of inactivation based on the temperature andpH of the water. The amount of log inactivation, andhence the CT value that the plant must achieve, isbased on SWTR guidance.

Inactivation requirements for Cryptosporidium basedon CT have not been established but would be sig-nificantly higher than those for Giardia and virus.Since inactivation of Cryptosporidium is difficult toachieve with chlorine disinfection, maximizing particleremoval could represent the most cost effective andviable option for maximizing public health protectionfrom this microorganism.

2.3.2 Basis for Optimization Goals

Strong evidence exists in support of maximizing pub-

lic health protection by optimizing particle removal ina plant. Recent supportive evidence from watertreatment research and field evaluations is summa-rized below:

Pilot study work conducted by Patania (12)showed that when treatment conditions wereoptimized for turbidity and particle removal, veryeffective removal of both Cryptosporidium andGiardia was observed. Cryptosporidium removalranged from 2.7 to 5.9 logs, and Giardia removalranged from 3.4 to 5.1 logs during stable filteroperation. Under the conditions tested, meeting

a filter effluent turbidity goal of 0.1 NTU wasindicative of treatment performance producingthe most effective cyst and oocyst removal. Asmall difference in filter effluent turbidity (from 0.1or less to between 0.1 and 0.3 NTU) produced alarge difference (up to 1.0 log) in cyst and oocystremoval.

Pilot study and full-scale plant work performed byNieminski (13) demonstrated that consistentremoval rates of Giardia and Cryptosporidiumwere achieved when the treatment plant wasproducing water of consistently low turbidity (0.1 -0.2 NTU). As soon as the plants performancechanged and water turbidity fluctuated, a highvariability in cyst concentration was observed incollected effluent samples. The pilot study work,confirmed by full-scale plant studies, showedthat in a properly


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operated treatment plant producing finishedwater of 0.1 to 0.2 NTU, either conventional treat-ment or direct filtration can achieve 3-log removalofGiardia cysts.

An extensive amount of water filtration researchwas conducted at Colorado State University onlow turbidity water (14,15). Using field-scale pilotfilters, researchers demonstrated greater than 2-log Giardia removal when proper chemicalcoagulation was practiced on low turbidity rawwater (i.e., 0.5 to 1.5 NTU), resulting in filter efflu-ent turbidity values of less than 0.1 NTU.

Filter plant performance evaluations conductedby Consonery (16) at 284 Pennsylvania filtrationplants over the past eight years have included acombination of turbidity, particle counting, andmicroscopic particulate analysis to assess theperformance of plant processes. The personcompleting the evaluation uses this information to

rate the plant as to whether it provides anacceptable level of treatment for microbial patho-gens. Evaluation results have shown that whenfilter effluent turbidity was less than or equal to0.2 NTU, 60 percent of the plants were given anacceptable rating. When filter effluent turbiditywas greater than or equal to 0.3 NTU, only11 percent of the plants were given an accept-able rating. Although this work did not assessplant performance at the 0.1 NTU level, theincreased acceptable rating that occurred wheneffluent turbidity was less than 0.2 NTU versus0.3 NTU indicates the benefit of lowering finished

water turbidity.

An extensive amount of research and field workresults support a filtered water turbidity goal of0.1 NTU. These findings are also compatible with along standing AWWA Policy Statement supportingtreatment to this level (17). It is important to under-stand that achieving this level of filter performance(i.e., 0.1 NTU) does not guarantee that microbialpathogens will not pass through filters; however, itrepresents the current best practice for water treat-ment plants to achieve the greatest level of publichealth protection.

Particle counting can be used to support andenhance turbidity measurements, and can beespecially useful when source water turbidity is low(< 5 NTU). At low source water turbidity levels, it isdifficult to assess the level of particle reduction beingachieved in the filtration process with turbiditymeasurements alone. This is due to the insensitivityof turbidimeters at extremely low turbiditymeasurements (i.e., below about 0.05 NTU)(18,19,20).

2.4 Optimization Performance Goals

For purposes of this handbook, optimized watertreatment performance for protection against micro-bial pathogens is defined by specific measurementsand goals. This section presents the performancegoals for surface water treatment systems. Thesegoals are based on CCP field work performed by theauthors and experience gained from the Partnershipfor Safe Waterand state optimization pilot programs.It is important to note that these goals are the foun-dation for all assessments in this handbook and thatobtaining this performance level exceeds presentregulatory requirements.

2.4.1 Minimum Data MonitoringRequirements

Daily raw water turbidity

Settled water turbidity at 4-hour time incrementsfrom each sedimentation basin

On-line (continuous) turbidity from each filter

One filter backwash profile each month fromeach filter

2.4.2 Individual Sedimentation BasinPerformance Goals

Settled water turbidity less than 1 NTU95 percent of the time when annual average rawwater turbidity is less than or equal to 10 NTU.

Settled water turbidity less than 2 NTU95 percent of the time when annual average rawwater turbidity is greater than 10 NTU.

2.4.3 Individual Filter Performance Goals

Filtered water turbidity less than 0.1 NTU

95 percent of the time (excluding 15-minuteperiod following backwashes) based on themaximum values recorded during 4-hour timeincrements.

If particle counters are available, maximumfiltered water measurement of less than 10particles (in the 3 to 18 m range) per millili-ter. (Note: The current state-of-the-artregarding calibration of particle counters andthe inherent problems in comparisons of


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readings between different counters must beconsidered in using particle count informa-tion to assess optimized performance.Higher readings than the above 10 parti-cles/mL goal from a counter that is properlycalibrated may be a function of differencesbetween instruments. Relative changes inparticle count data will be of greater use in

assessing optimized performance than theabsolute values from the particle counter).

Maximum filtered water measurement of0.3 NTU.

Initiate filter backwash immediately after turbiditybreakthrough has been observed and beforeeffluent turbidity exceeds 0.1 NTU.

Maximum filtered water turbidity following back-wash of less than 0.3 NTU.

Maximum backwash recovery period of15 minutes (e.g., return to less than 0.1 NTU).

2.4.4 Disinfection Performance Goal

CT values to achieve required log inactivation ofGiardia and virus.

2.5 Role of the Water Treatment Plant

Staff in Public Health Protection

The information presented in this chapter demon-strates that the quality of water leaving a watertreatment plant has the potential to directly impact thehealth of the consumers of its finished water. All staffassociated with the plant, from the operator to thehighest level administrator, have an important role inprotecting public health and a responsibility toprovide finished water that minimizes the possibilityof a disease outbreak. Experience gained fromimplementing CCP optimization activities at plantshas demonstrated that, in most situations, once utilitystaff become aware of the importance of achieving

optimized performance goals, they haveenthusiastically pursued these goals through avariety of activities. Later chapters presentcomprehensive procedures for assessing andachieving the level of performance described in thischapter.

2.6 References

1. Kramer, M.H., et al. 1996. Waterborne Dis-ease: 1993 and 1994. Journal AWWA,88(3):66.

2. Chauret, C., et al. 1995. Correlating Crypto-sporidium and Giardia With Microbial Indicators.Journal AWWA, 87(11):76.

3. LeChevallier, M.W., et al. 1995. Giardia andCryptosporidium in Raw and Finished Water.Journal AWWA, 87(9):54.

4. States, S., et al. 1997. Protozoa in River Water:Sources, Occurrence, and Treatment. Journal

AWWA, 89(9): 74.

5. Solo-Gabriele, H., et al. 1996. U.S. Outbreaksof Cryptosporidiosis. Journal AWWA, 88(9):76.

6. Pett, B., et al. 1993. Cryptosporidiosis Out-break From an Operations Point of View:

Kitchener-Waterloo, Ontario. Paper presentedat AWWA Water Quality Technology Conference,Miami, FL.

7. Richardson, A.J., et al. An Outbreak of Water-borne Cryptosporidiosis in Swindon andOxfordshire. Epidemiol. Infect., 107(3)485.

8. Korich, D.G., et al. 1990. Effects of Ozone,Chlorine Dioxide, Chlorine, and Monochloramineon Cryptosporidium parvum Oocyst Viability.

Applied and Environmental Microbiology,56(5):1423.

9. Finch, G.R., et al. 1995. Ozone and ChlorineInactivation ofCryptosporidium. In Proceedingsof Water Quality Technology Conference,November 6-10, 1994, San Francisco, CA.

AWWA, Denver, CO.

10. USEPA. 1997. National Primary Drinking WaterRegulations: Interim Enhanced Surface WaterTreatment Rule; Notice of Data Availability; Pro-posed Rule. Fed. Reg., 62:212:59486 (November3, 1997).

11. Guidance Manual for Compliance With the Filtra-tion and Disinfection Requirements for PublicWater Systems Using Surface Water Sources.1989. NTIS No. PB-90148016, USEPA,Cincinnati, OH.

12. Patania, N.L., et al. 1996. Optimization of Filtra-tion for Cyst Removal. AWWARF, Denver, CO.


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13. Nieminski, E.C., et al. 1995. Removing Giardiaand Cryptosporidium by Conventional Treatmentand Direct Filtration. Journal AWWA, 87(9):96.

14. Mosher, R.R., et al. 1986. Rapid Rate Filtrationof Low Turbidity Water Using Field-Scale PilotFilters. Journal AWWA, 78(3):42.

15. Al-Ani, M.Y., et al. 1986. Removing GiardiaCysts From Low Turbidity Water by Rapid SandFiltration. Journal AWWA, 78(5):66.

16. Consonery, P.J., et al. 1996. Evaluating andOptimizing Surface Water Treatment Plants:How Good is Good Enough? Paper presentedat AWWA Water Quality Technology Conference,November 1996, Boston, MA.

17. AWWA Statement of Policy. 1968. QualityGoals for Potable Water, Journal AWWA,60(12):1317.

18. Cleasby, J.L., et al. 1989. Design and OperationGuidelines for Optimization of the High Rate Fil-tration Process: Plant Survey Results.

AWWARF, Denver, CO.

19. West, T., P. Demeduk, G. Williams, J. Labonte,A. DeGraca, and S. Teefy. 1997. Using ParticleCounting to Effectively Monitor and OptimizeTreatment. Paper presented at AWWA AnnualConference, Atlanta, Georgia.

20. Veal, C., and B. Riebow. 1994. Particle MonitorMeasures Filter Performance. Opflow, 20(5):1.


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Chapter 3Assessing Composite Correction Program Application

3.1 Introduction

The CCP is currently used as an optimization tool byseveral EPA regional offices and state drinking waterprograms, and its use could increase as the result ofpossible new turbidity requirements when the InterimEnhanced Surface Water Treatment Rule (IESWTR)is promulgated (1). However, the most effectiveapplication of the approach has not always beenachieved. Results from CCP field experience andstate pilot programs have indicated that the CCP ismost effective when it is strategically integrated into aprogram that focuses on area-wide optimization ofwater treatment systems. This chapter describes adeveloping program for regulatory agencies and oth-

ers to initiate effective CCP-based optimization activi-ties through the implementation of an area-wideoptimization model.

3.2 Optimization Program Experience

The experience gained from the transfer of CCPcapability to state drinking water programs is dis-cussed in Chapter 1. These activities provided valu-able insights into the use of the CCP as an optimiza-tion tool by primacy agencies. The objective of theearly pilot programs was to demonstrate the capa-

bility to effectively transfer CCP skills to state per-sonnel and to facilitate state-wide implementation ofthese activities. Several challenges becameapparent during the implementation phase. The CCPapproach, while considered extremely valuable, wasalso considered to be resource intensive and, there-fore, in competition with other state program activi-ties. In some states with decentralized programs,field and central office personnel had difficulty defin-ing their roles and responsibilities for implementingoptimization activities. Primacy agency policiesguiding the implementation of follow-up efforts weresometimes challenged (e.g., enforcement versusassistance responsibilities). As the state pilot pro-

grams progressed, these challenges to implementa-tion became known collectively as institutional barri-ers. In some cases these institutional barriers werepervasive enough to prevent state teams trained inCCP procedures from using their new technical skillsat plants with potential public health concerns.

Despite the identified institutional barriers, the con-tinued success of the CCP efforts at individual facili-ties could not be ignored (2). In addition, experience

gained from the broad-scale implementation of theCCP through state optimization pilot programs and

the Partnership for Safe Water demonstrated thatimprovement in water treatment performance couldbe achieved through multiple activities that are basedon CCP concepts. Some specific examples include:

Self-Assessment Based on CCP CanPositively Impact Performance: Activities thatinvolve water utilities with the development andinterpretation of their turbidity data have providedutility staff with a different perspective onassessing their performance and have resulted inutility-directed changes to their operation andsystem that have improved performance.Specifically, many water utilities that have par-ticipated in the Partnership for Safe Waterhaveacknowledged that associated turbidity datatrending activities have focused them onimproving their plant performance to achieve thePartnership goals (3).

Centralized Training Using CCP PrinciplesCan Impact Multiple Facilities: The applicationof CCP-based principles through centralized,facilitated training workshops represents aneffective and efficient approach to assist a groupof utilities with achieving optimization goals.Specifically, a training facilitator in Pennsylvania,working with a group of water utilities, used CCP-based process control procedures in a workshopformat to improve coagulant dosing understand-ing and application (4).

CCP Components Can be Used to EnhanceExisting State Program Activities: Aligningexisting programs (e.g., sanitary surveys, facilityoutreach) with the CCP approach can enhanceachievement of performance goals. Forexample, existing state sanitary survey


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programs in Texas and Pennsylvania weremodified to include performance-related CPEactivities (e.g., individual filter evaluations, filterbackwash special studies, process controlinterviews) (5).

These findings supported a strategic change in theCCP direction. The result was an organizational

framework for implementing optimization activities onan area-wide basis.

3.3 Area-Wide Optimization Model

An area-wide optimization model was developed thatcreates an environment to effectively apply existingresources (e.g., state programs and personnel) withproven performance improvement tools (e.g., CCP).Major components of the current model include:Status, Evaluation, Follow-Up and Maintenance.These components are described in Figure 3-1.

This model represents a proactive approach topublic health protection, serving to promotecontinuous improvement and addressingperformance-related issues when they first becomeapparent. Pervasive throughout the area-wideoptimization program is an awareness buildingprocess linking treatment plant performance withpublic health protection. It is important to note thatan area-wide optimization program is an ongoingactivity with an overall objective to improve theperformance level of all water systems.

Future activities are planned to enhance the area-

wide optimization model. Potential activities includeexpanded optimization efforts at surface watertreatment facilities (e.g., disinfection by-products,source water protection, distribution system waterquality), and optimization activities related to groundwater systems.

3.3.1 Status Component

Status Component activities are designed to deter-mine the status of water systems relative to opti-mized performance goals within a defined area (e.g.,

state, region, district). Implementers of optimizationprograms then use the results of these activities in aprioritization process to continuously focus availableresources where they are most needed, typically athigh risk public health systems. A key activity underthe Status Component is continuous performancemonitoring, which can be used to effectively measurethe success of the various optimization efforts asso-ciated with the model.

3.3.2 Evaluation Component

Evaluation Component activities focus on the deter-mination of factors limiting performance for thosewater systems where performance problems wereidentified from Status Component activities. Existingevaluation programs can be utilized by incorporatingperformance-focused activities. The most resource-

intensive evaluation tools, such as CPEs, are appliedat water systems presenting the greatest risk to pub-lic health.

3.3.3 Follow-Up Component

Follow-Up Component activities focus on identifyingand developing technical assistance methodologies,such as the CTA, to systematically address perform-ance limiting factors at these systems. Coordinationand training of available technical resources (e.g.,state drinking water program trainers, non-profit

organizations, water system peers, consultants) areimportant activities to assure consistency and effec-tiveness of this component. The degree of involve-ment of regulatory agency personnel in follow-upactivities may be impacted by the agencys policieson enforcement versus technical assistance. Inthese situations, policies should be clearlyestablished and agreed upon by agency staff prior toimplementing follow-up activities.

3.3.4 Maintenance Component

The Maintenance Component formalizes a feedbackloop to integrate the lessons learned from the vari-ous component activities back into the model. Inaddition, these lessons learned can provide oppor-tunities to coordinate findings with other related pro-grams.

3.4 Implementation of an Area-Wide

Model

Figure 3-2 shows the status of filtration plant turbidityperformance during a two-year period when a state

was initiating an area-wide optimization program (5).For those plants that achieved improved performancelevels, this progress was accomplished through theirparticipation in Status Component activities such asturbidity monitoring and Follow-Up Componentactivities such as chemical feed training. This figuredemonstrates some of the benefits of using theStatus Component to continuously monitor the watersystems level of performance relative to the desiredperformance goal. For example, systemsrepresenting the greatest public health risk are


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apparent. In addition, systems showing improvedperformance can be assessed to ascertain thereasons for such improvement. In some cases, anawareness of the importance of optimized

performance by the water system has been identifiedas a major contributing factor for the change.

Figure 3-1. Area-wide optimization model.

STATUS COMPONENT Establish optimized performance goals. Routinely prioritize water systems based on public health risk. Continuously monitor and assess performance data. Incorporate performance-based activities into existing surveillance programs. Establish feedback mechanism to include monitoring and surveillance data into

ongoing prioritization process.

EVALUATION COMPONENT Focus existing programs on optimized performance goals. Use CCP-based evaluations to identify factors limiting performance. Implement CPEs at high risk systems. Identify and develop resources to provide CCP-based evaluations.

FOLLOW-UP COMPONENT Establish parties responsible for follow-up component activities.

Utilize a follow-up protocol that systematically addresses factors limitingperformance. Identify and develop resources to provide CCP-based follow-up activities. Coordinate existing programs to complement performance improvement efforts.

MAINTENANCE COMPONENT Integrate optimization efforts with other drinking water program activities, such

as design review, training, and funding. Identify and implement ongoing optimization program refinements.

Figure 3-2. Area-wide treatment plant performance status.


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0

10

20

30

40

50

60

70

80

90

100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

System

PercentTimeTurbidity 95 % time 0

50 - < 95 % time 5

< 50 % time 10

Does the water system experience post filter backwash turbidity of > 0.3 NTU forgreater than 15 minutes?

0 10

Does the water system achieve the optimization turbidity goal for settled water (e.g., 9 feet.


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The approach to determine whether a unit process isType 1, Type 2 or Type 3 is based on the relationshipof the position of horizontal bars to the position of thepeak instantaneous operating flow rate. It is notedthat if a plant operates at peak instantaneousoperating flow with one unit out of service, then theevaluation would be based on these conditions. Aspresented in Figure 4-5, a unit process would be

rated Type 1 if its projected capability exceeds thepeak instantaneous operating flow rate, Type 2 if itsprojected capability was 80 to 100 percent of peak, orType 3 if its projected capability is less than80 percent of peak.

Figure 4-5. Major unit process rating criteria.

FlowUnit Process

Flocculation

Sedim entation

Filtration

Disinfection

Type 1

Type 2

Type 1

Type 3 < 80% of peak flow

Peak Instantaneous O perating Flow Rate

> 100% of peak flow

80 - 100% of peak flow

> 100% of peak flow

4.2.2.3 Determining Peak Instantaneous

Operating Flow

A key aspect of the major unit process evaluation isthe determination of peak instantaneous operatingflow rate. This is the flow rate against which the

capability of each of the major unit processes isassessed. Based on this assessment, the unitprocess type is projected, which determines if majorconstruction will be required at the plant.

An additional evaluation of both the peak instanta-neous operating flow rate and plant operating timeallows the evaluator to determine if plant capabilitycan be enhanced by reducing the plant flow rate andextending the plant operating time. Some plants onlyoperate for part of the day and shut down at night. In

these cases, the peak instantaneous operating flowrate of the plant could be occurring only over a 12-hour period, and the plant may be able to operate athalf the flow rate for a 24-hour period. In thisexample, a unit process that received a Type 3 ratingmay be able to achieve Type 2 or Type 1 status.When a plant decides to reduce flows, however,there probably will be additional expenses for staff to

operate the plant for the extended time periodsneeded to meet water demand. Basically the plant istrading off the costs for staff with those required toconstruct additional treatment capacity. In addition,it may be possible for a community to take steps toreduce demand by activities such as increasing waterrates, water rationing, or leak detection and repair oftheir distribution system.

The peak instantaneous operating flow rate and unitprocess loadings need to be carefully selected andassessed by the evaluator since these parameters inthe unit process evaluation can direct the utility either

toward construction or pursuing optimization withexisting facilities. During a CPE every effort shouldbe made to direct the plant toward optimization withexisting facilities. In completion of the major unitprocess evaluation, this means that selection ofparameter(s) such that it directs a plant to pursuemajor construction should be made after muchconsideration of the impacts on optimizedperformance and public health protection.

Peak instantaneous operating flow rate is identifiedthrough review of operating records and observationof operation practices and flow control capability. A

review of plant flow records can be misleading indetermining peak instantaneous flow. For example,records may indicate a peak daily water productionvalue, and discussions with the operating staff mayindicate that the plant was not operated for a full 24-hour period. If the recorded production was not forthe full 24-hour period but had been determined bycalculating an average flow rate over the 24-hourperiod, a rate that was less than the actual peakinstantaneous operating flow would be identified.Peak instantaneous operating flow is that flow ratewhich the unit processes actually receive. Forexample, a plant may have two constant speed raw

water pumps each capable of pumping at 1,000 gpm.If only one is operated at a time for 12 hours per day,the peak instantaneous flow rate would beestablished at 1,000 gpm. If, however, operatingpersonnel indicate that a control valve is used tothrottle the pump to 750 gpm on a continuous basis,the peak instantaneous flow rate would beestablished at 750 gpm. In a third situation, the plantstaff may operate both pumps during times of thepeak water demand (e.g., summer) which ideallywould make the peak instantaneous flow rate


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2,000 gpm. It is noted that the peak flow rate whenboth pumps are operated is often lower than whenusing a single pump. The maximum value for the twopumps should be used even if the plant only operatesthis way for a few days at a time.

4.2.2.4 Rating Individual Unit Processes

The next step in preparing a performance potentialgraph is selecting appropriate loading rates for eachof the major unit processes. Once the loading ratesare selected, the performance potential of a unitprocess to achieve optimized performance goals canbe projected. The criteria presented in Table 4-2 canbe used to assist in selecting loading rates forindividual unit processes. There is a wide range inthe criteria which can translate into large differencesin the projected unit process capabilities. Criteria tohelp in adjusting loading rates for site-specificconditions are provided. However, using the

performance potential graph approach requires agreat deal of judgment on behalf of an experiencedwater treatment plant evaluator to properly projectcapability of a major unit process.

It is noted that other resources are available to assistless experienced evaluators in completing a major

unit process evaluation. One of these resources isthe Water Advisor expert system (2) which preparesa major unit process evaluation based on pre-selected loading rates. This program, developed toassess plants based on 1989 SWTR compliance, isseveral years old; and the loading rates have notbeen recently updated. When using this program,the evaluator has no opportunity to change loading

rates based on the unique conditions of a particularplant. An inexperienced evaluator may find this auseful tool to check the major unit process evaluationcompleted using the procedures in this handbook. Afurther description of this software is contained in

Appendix B.

An additional resource is the Partnership for SafeWater software (1). A copy of this software, as wellas a description of its use, is located in Appendix C.The Partnership for Safe Water software providessuggested loading rates based on industry standardsand operating experience, but also allows the CPE

evaluator to easily change loading rates and plotdifferent performance potential graphs.

The criteria presented in Table 4-2 are considered tobe the most current, relative to achieving

Table 4-2. M ajor Unit Process Evaluation Criteria(1,2,3,4,5,6,7)

Hydraulic Sedimentation (cold seasonal water 14 >16 0.7 1.0 0.5

Filtration Air Binding Loading Rate

Sand Media None 2.0 gpm/ft2

Conventional (circular and rectangular) and solids contact units -

Exists 1.0-1.5 gpm/ft2

with vertical (>45o) tube settlers

Operating Mode

Dual/Mixed Media None 4.0 gpm/ft2 Turbidity Removal Softening Color Removal

Exists 2.0-3.0 gpm/ft2

Depth SOR SOR SOR

(ft) (gpm/ft2) (gpm/ft

2) (gpm/ft

2)

Deep Bed None 6.0 gpm/ft2

10 1.0 1.5 0.5

(Typically anthracite Exists 3.0-4.5 gpm/ft2

12 - 14 1.5 2.0 0.75

>60 in. in depth) >14 2.0 2.5 1.0

*If long term (12 m onths) data m onitoring indicates capability to m eet perform ance goals at higher loading rates, then these rates can be used.


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optimized performance goals and are the criteria thatare used for development of the major unit processevaluation for this handbook. However, theperformance of the unit process in meeting theoptimized performance goals should be a majorconsideration in the selection of evaluation criteria.The situation where a unit process continuouslyperforms at optimized levels should not be rated as a

Type 2 or Type 3 unit process merely based on thecriteria in Table 4-2. Specific guidance for assessingeach unit process is described in the followingsections.

Flocculation

Proper flocculation requires sufficient time to allowaggregation of particles so that they are easily re-moved in the sedimentation or filtration processes.The capability of the flocculation process is projectedbased on the hydraulic detention time in minutes

required to allow floc to form at the lowest watertemperature. Judgment is used to adjust theselected times based on the type of treatment plant,number of stages, and ability to control mixingintensity.

Selection of the required detention time for adequateflocculation can vary widely depending on watertemperature. For example, at plants where watertemperatures of less than 5

oC (41

oF) occur, floc

formation can be delayed because of the cold water.In these instances, longer (e.g., 30-minute) detentiontimes may be required. If temperatures are not as

severe, detention times as low as 15 minutes or lesscould be considered adequate.

Other factors to consider include the number offlocculation stages and the availability of variableenergy input to control flocculation. A minimum ofthree stages of flocculation is desirable. However,because the baffling and variable mixing energy canoften be added or modified through minormodifications, these items are not considered assignificant in determining the basin capability rating.Baffling a flocculation basin to better achieve plugflow conditions can often significantly improve the

size and settleability of the floc. If adequate basinvolume is available (i.e., typically a Type 1 unitprocess), a one-stage flocculation basin may resultin a Type 2 rating with the stipulation that bafflingcould be provided to overcome the single-stagelimitation if it was shown to be limiting in follow-upCTA activities.

The following guidelines are provided to aid in se-lecting a hydraulic detention time to be used in

development of the flocculation unit process per-formance potential:

Desired hydraulic detention times for floc for-mation are:

Typical range: 15 to 30 minutes.

Cold low turbidity waters (e.g.,


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detention time. In these cases, state criteria may beused to project sedimentation treatment capability.However, if data exists that indicates thesedimentation basins can produce desired per-formance at rates above the state rate, it may bepossible to obtain a variance from the state criteria.

As shown in Table 4-2, the availability of or the

addition of tube or plate settlers in existing tankagecan be used to enhance the performance potential ofthe sedimentation process (e.g., perform at higherSORs). Upflow-solids-contact clarifiers represent aunique sedimentation configuration since theycontain both a flocculation and sedimentationprocess that have been designed as a single unit.These units can be rated using the center volume toassess the flocculation capability and the clarifiersurface area to rate the sedimentation capability.

The following guidelines are suggested to aid inselecting a surface overflow rate to be used in the

development of the sedimentation unit processcapability.

SORs to project performance potential for rec-tangular, circular, and solids contact basins,operating in a temperate climate with cold sea-sonal water (< 5

oC) are shown in Table 4-2.

SORs to project performance potential for basinswith vertical (> 45) tube settlers, operating in atemperate climate with cold seasonal water (10,000.Systems with a population of 10,000 to address improvements inmicrobial control and risk-risk trade-off issuesrelated to the Stage 1 DBP regulation whichwould be implemented at the same time.

A Long Term ESWTR (LTESWTR) that wouldapply to PWSs


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During the Reg-Neg process there was alsoagreement that additional data and research wasneeded on occurrence, treatment capabilities, andhealth effects of both microbials and DBPs to providea sound technical basis for these regulations. Theseissues were to be resolved by:

An Information Collection Rule (ICR) to collectoccurrence and treatment information to evaluatepossible components of an IESWTR, LTESWTR,and Stage 2 DBP regulations.

Additional research, including health effectsstudies, to support regulatory development.

In July 1994, USEPA proposed a Stage 1 DBPregulation (4) and an IESWTR (5) which reflected the1992-93 negotiations. The ICR was promulgated inMay 1996 (6) with data collection starting in July1997 and continuing for 18 months. Based on thisschedule, the ICR data will not be collected, validated

and available for regulation development untilJanuary 2000.

In August 1996 congress passed amendments to theSafe Drinking Water Act (SDWA) (7) that includedthe following statutory deadlines for USEPA topromulgate the M-DBP regulations:

IESWTR and Stage 1 DBPs - November1998

LTESWTR - November 2000

Stage 2 DBPs - May 2002

These deadlines were such that it would beimpossible to use the ICR data to develop theIESWTR and LTESWTR as intended by Reg-Neg. Inearly 1997, USEPA formed the M-DBP AdvisoryCommittee under the Federal Advisory Committee

Act (FACA) to help the Agency meet the new SDWAdeadlines. This resulted in an agreement in principlethat formed the basis for the Notice of Data

Availability (NODA) for the Stage 1 DBP (8) and theIESWTR (9) to supplement the 1994 proposal forthese regulations. Based on comments on the 1994proposals and these NODAs, the IESWTR will be

promulgated in November 1998. USEPA plans topromulgate the LTESWTR in 2000 in order to meetthe SDWA mandate with a compliance date that willcorrespond to the Stage 1 DBP regulations forPWSs


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1. any individual filter with a turbidity level greaterthan l.0 NTU based on two consecutivemeasurements fifteen minutes apart; and

2. any individual filter with a turbidity level greaterthan 0.5 NTU at the end of the first four hours offilter operation based on two consecutivemeasurements fifteen minutes apart.

The Committee also recommended that if an indi-vidual filter has turbidity levels greater than l.0 NTUbased on two consecutive measurements fifteenminutes apart at any time in each of threeconsecutive months, the system should be requiredto conduct a self-assessment of the filter, utilizing asguidance relevant portions of guidance issued by theEnvironmental Protection Agency for ComprehensivePerformance Evaluation (CPE). Also, if an individualfilter has turbidity levels greater than 2.0 NTU basedon two consecutive measurements fifteen minutesapart at any time in each of two consecutive months,

the system should be required to arrange for theconduct of a CPE by the State or a third partyapproved by the State.

The IESWTR is scheduled for promulgation inNovember 1998, at which time the specificturbidity requirements and provisions will beavailable. EPA will issue detailed guidance atthat time on the relevant technical informationneeded to comply with the rule. Both theLTE1ESWTR and LT2ESWTR are in pre-developmental stages.

Figure 7-1 also shows the turbidity goal of 0.1 NTUthat was discussed in previous chapters of thishandbook and how regulated turbidity levels areapproaching this long held turbidity goal. This is notintended to predict that future regulations will be setat the 0.1 NTU level, but to encourage plants topursue the 0.1 NTU performance goals outlined inthis handbook, as a way to assure regulatory

compliance on a combined plant basis.

7.3.2 Removal/Inactivation Requirements

The original SWTR required water systems to pro-vide a minimum of 3-log removal/inactivation ofGiardia cysts. State regulatory agencies thatreceived primacy from USEPA were given broadlatitude in how plants would meet this requirement,including the option to increase theremoval/inactivation requirements for water systemsthat may have higher levels of cysts in their source

water. Rule guidance stated that properly operatingfiltration plants could be expected to remove between2.0 to 2.5-log ofGiardia cysts, and this removal couldbe credited against the 3-log requirement. Theremaining log removal was to be achieved withdisinfection. Log removal credits for variousdisinfectants and operating conditions were providedin tables of disinfectant concentration (C) multipliedby the contact time (T).

A major impetus for the IESWTR was that Crypto-sporidium was not regulated under the original

Figure 7-1. Historic perspective of turbidity goal and regulations.

Optimized Performance Goal (0.1 NTU)

SDWA (1.0 NTU)

SWTR (0.5 NTU)

IESWTR (0.3 NTU)

Stage 1 DBPs

LTESWTR

Stage 2 DBPs

LT2ESWTR

0

0.5

1

1.5

2001

1968

1971

1974

1977

1980

1983

1986

1989

1992

1995

1998

2004

T

urbidity(NTU)

SWTR. This was of concern since chlorine is not aneffective disinfectant against Cryptosporidium, and

the impact of other disinfectants (e.g., ozone,chlorine dioxide) has not been well established.


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The 1997 M-DBP Federal Advisory Committeerecommended adoption of a 2-log Cryptosporidiumremoval requirement for all surface water systemsthat serve more than 10,000 people and are requiredto filter. The committee also recommended thatsystems which use rapid granular filtration (directfiltration or conventional filtration treatment - ascurrently defined in the SWTR) and meet

strengthened turbidity requirements would beassumed to achieve at least a 2-log removal ofCryptosporidium. Systems which use slow sandfiltration and diatomaceous earth filtration and meetexisting SWTR turbidity performance requirements(less than 1 NTU for the 95th percentile or alternativecriteria as approved by the State) also would beassumed to achieve at least a 2-log removal ofCryptosporidium.

The IESWTR is scheduled for promulgation inNovember 1998, at which time the specificremoval requirements and provisions will be

available. EPA will issue detailed guidance atthat time on the relevant technical informationneeded to comply with the rule. Both theLTE1ESWTR and LT2ESWTR are in pre-developmental stages.

7.3.3 DBP Maximum Contaminant Levels(MCLs)

DBPs were first regulated in 1979 (12) when an MCLof 0.10 mg/L was established for the sum of fourtrihalomethanes (THM), which applied to only those

water systems serving populations >10,000 persons.As discussed above, the purpose of the M-DBPregulations is to reduce the health risk for thesecompounds and other DBPs by promulgation ofdisinfectant and disinfectant by-product (D/DBP)regulations to be implemented in two stages. TheNODA for Stage 1 of the D/DBP rule has lowered theMCL for THMs and a new MCL has been added forthe sum of five additional compounds calledhaloacetic acids (HAA5). The NODA also containsmaximum residual disinfectant levels (MRDLs)permitted in the distribution system.

Fundamental control procedures for THMs and HAAsremain essentially the same and include:

Removal of natural organic matter (NOM), whichare precursors, in the raw water.

Altering the point of disinfectant addition.

Reducing the amount of disinfectant used.(NOTE: This may not be feasible because ofmicrobial backstop requirements.)

Switching to alternate disinfectants.

In conventional treatment, NOM is removed by acoagulation/adsorption mechanism accomplished bychanging the coagulation process to enhance theremoval of these organics. A potential conflict existsfrom the standpoint of plant process controlprocedures; chemical feed rates found to meet theoptimized turbidity performance goals described inthis handbook may not be compatible with thoseneeded to meet the DBP performance goals. Someresearch has shown, however, that enhancedcoagulation conditions also achieved excellentturbidity removal in jar tests. Few studies haveevaluated the impacts of enhanced coagulation onfilterability which may be more of a problem.

Altering the plants disinfection practices to meet theDBP MCLs, either through changing the point ofdisinfectant addition or lowering the disinfectantdose, can potentially also lead to other types of

conflicts. When disinfectants are added ahead of thetreatment plant (e.g., pre-chlorination), they can alsoprovide additional important benefits (e.g., enhancethe coagulation process for turbidity removal,enhance iron and manganese control, etc.) alongwith meeting the plants CT requirements. Loweringpre-disinfection doses to reduce DBP formation,therefore, could result in turbidity performanceproblems or higher levels of iron and manganese inthe finished water. The major consideration inchanging disinfection practices to control DBPs,however, is to assure that the change will not resultin compliance problems with state SWTR disinfection

and the IESWTR microbial backstop requirements.The major unit process evaluation described inChapter 4 presents disinfection conditions (e.g.,chlorine residual, pH) that are necessary to achievedesired inactivation levels.

If none of the above process control changes aresufficient to control DBPs, then the utility may have toconsider alternate disinfection including


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ozone, chlorine dioxide, or chloramines. Ozone andchlorine dioxide will result in major modifications tothe treatment plant and will require the design andinstallation of new treatment processes andequipment. Chloramines, depending on the plant,may be considered a modification that would beaddressed as part of a CTA.

7.3.4 Enhanced Coagulation Requirements

The Stage 1 DBP regulations proposed in the NODAfor the first time require surface water systems thatuse conventional treatment or softening to remove aspecified minimum percentage of the total organiccarbon (TOC) from their raw water using a processcalled enhanced coagulation. TOC removal isrequired because other DBPs besides THMs andHAAs are formed when disinfectants react with aNOM, measured as TOC. The occurrence andhealth effects of these unidentified DBPs are

unknown at this time. The intent of this part of theproposed regulation is to control the formation ofunknown, as well as known, DBPs by requiring that aminimum percentage of NOM in the raw water,measured as TOC, is removed by the plant.

The percentage of TOC removal required is based onthe TOC and alkalinity levels of the plants raw water.These TOC removal requirements are broken downinto nine different percent TOC removal categories.They are presented in a table for three differentalkalinities and raw water TOC levels.

Plants that cannot meet the specified percent TOCremovals will follow a Step 2 procedure todetermine what levels of TOC removal are rea-sonable and practical to achieve. The plant usesthis information to request an alternative TOCremoval requirement from its primacy regulatoryagency.

The Step 2 procedures consist of special jar tests todetermine the maximum percent TOC removal thatthey can achieve by incremental increases incoagulant dose. Coagulant dose is increased in 10mg/L increments until a specified pH level

(depending on the raw water alkalinity) is achieved.Residual TOC levels in each jar are then measured,and an analysis is made of the point of diminishingreturn (PODR). The PODR is defined as when a 10mg/L increase in coagulant does not decrease theresidual TOC by more than 0.3 mg/L. Thispercentage TOC removal would then be consideredreasonable and practical and would be used indiscussions with the primacy agency relative to givingthe plant an alternate enhanced coagulationrequirement.

When a water system meets one of a variety ofconditions it may be exempted from the enhancedcoagulation part of the regulation. It was recognizedthat only the humic fraction of the raw water TOC isamenable to removal by enhanced coagulation.Plants, therefore, with high levels of non-humic TOCmay not be able to meet any of the enhancedcoagulation removal requirements and could be

exempt from this part of the regulations. Plants canassess the amount of humics in their raw water bymeasuring its specific UV absorbance or SUVA.SUVA is defined as the UV absorbance divided bythe dissolved organic carbon (DOC). SUVAs of


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(disinfectant residual concentration(s); contacttime(s); temperature(s); and, where necessary,pH(s)).

The second part of the microbial backstoprequirement is benchmarking, which quantifies thelower bound of the systems current disinfectionpractices. It is intended that water systems take the

results from the profiling and work with the stateregulatory agency to evaluate changes in disinfectionpractices which could be used to control DBPs sothat these changes result in no significant decreasesin microbial protection. Benchmarking is onlyrequired if a PWS intends to make a significantchange to its disinfection practices such as movingthe point of disinfection, changing disinfectants,changing the disinfection process, or any changesthe state considers significant.

Part of the concern that led to the microbial backstopwas based on data that showed water plants with

widely varying disinfection levels. Figure 7-2 showsa profile where it is apparent that the plant was notoperating their disinfection systems at any commonbaseline. Day-to-day variations above the statedisinfection requirement could be caused by plantsnot determining their required CT based on seasonal

changes in water temperature and pH and/or nothaving close operational control over the actual CTprovided by the plant. An example would be notchanging the applied disinfectant dose to respond tochanges in the required CT, disinfectant demand,and/or operating flow. Plants could also be addingdisinfectant for other treatment issues such as tocontrol Fe, Mn, algae, and/or taste and odor. The

microbial backstop would require water systems tounderstand in more detail how much disinfectant theyare applying on a daily basis, and it would force themto make rational decisions on why they are addinghigher levels of disinfectant above that required forthe states disinfection requirements.

7.4 Summary

Water systems pursuing optimization for public healthprotection must remain vigilant concerning theramifications of new and changing regulations.

Those plants that have met the optimizedperformance goals defined in this handbook shouldbe well positioned to take those regulations in strideand continue to meet the ever more stringentchallenges facing the water industry.

Figure 7-2. Example of disinfection profile daily variations in log inactivation.

Why the Difference?

Improper Operational Practices

Fe and Mn Control

Taste and OdorAlgae

State Disinfection Requirement

7.5 References

1. Means, E.G. and S.W. Krasner. February 1993.D-DBP Regulation: Issues and Ramifications.Journal AWWA, 85:2:68. Denver, CO.

2. Pontius, F.W. September 1993. Reg-NegProcess Draws to a Close. Journal AWWA,85:9:18. Denver, CO.

3. Roberson J.A., J.E. Cromwell, S.W. Krasner,M.J. McGuire, D.M. Owen, S. Regli, and R.S.Summers. October 1995. The D/DBP Rule:


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Where did the Numbers Come From? JournalAWWA, 87:10:48. Denver, CO.

4. USEPA. July 29, 1994. National PrimaryDrinking Water Regulations: Enhanced SurfaceWater Treatment Requirements; Proposed Rule.Fed. Reg., 59:145:38832.

5. USEPA. July 29, 1994. National PrimaryDrinking Water Regulations: Disinfectants andDisinfection By-products; Proposed Rule. Fed.Reg., 59:145:38668.

6. USEPA. May 14, 1996. National PrimaryDrinking Water Regulations: MonitoringRequirements for Public Drinking Water Sup-plies. Fed. Reg., 61:94:24353.

7. US Code. August 6, 1996. Title XIV of thePublic Health Service Act (The Safe DrinkingWater Act) as Amended by Public Law 104-182.

8. USEPA. November 3, 1997. National Primary

Drinking Water Regulations: Disinfectants andDisinfection By-products; Notice of DataAvailability; Proposed Rule. Fed. Reg.,62:212:59338.

9. USEPA. November 3, 1997. National PrimaryDrinking Water Regulations: Interim EnhancedSurface Water Treatment Rule; Notice of Data

Availability; Proposed Rule. Fed. Reg.,62:212:59486.

10. USEPA. December 4, 1975. National InterimPrimary Drinking Water Regulations. EPA-570/9-76-003.

11. USEPA. June 29, 1989. Filtration and Disin-fection: Turbidity, Giardia lamblia, Viruses,Legionella, and Heterotrophic Bacteria; FinalRule. Fed. Reg., 54:124:27486.

12. USEPA. November 29, 1979. National PrimaryDrinking Water Regulations: Control ofTrihalomethanes in Drinking Water; Final Rule.Fed. Reg., 44:231:68624.


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Chapter 8Other CCP Considerations

8.1 Introduction

The purposes of this chapter are to present trainingrequirements for persons wanting to conduct CCPactivities and to identify parameters that can be usedby CCP providers or recipients of CCP services toassure quality control of the CCP approach. Inaddition, a brief discussion is presented concerningthe applicability of the CCP approach to otheroptimization and compliance activities that a utilitymay be required to achieve now or in the future.

8.2 Developing CCP Skills

8.2.1 CPE Training Approach

In Chapters 4 and 5 the type of training and expe-rience necessary to implement CPEs and CTAs wasdiscussed. In addition to these basic skillrequirements, it has been demonstrated that hands-on training is very effective for developing CCP skillsin interested parties. For conducting CPEs, a trainingapproach has been formalized and demonstratedwith several state drinking water program personnel.The training consists of trainees participating in aone-day seminar that provides instruction andworkshop opportunities for them to become familiar

with the CPE terminology and approach. Thisseminar is followed by three actual CPEs where thetrainees gain CPE skills through progressive trainingthat is facilitated by experienced CPE providers. Theroles of the CPE provider and trainee are describedin Table 8-1. During the first CPE, the trainees areinvolved in the data collection and special studyactivities but are largely in an observation role duringthe kick-off meeting, interview, and exit meetingactivities. Involvement in the remaining two CPEs isgradually increased such that by the time the thirdCPE is conducted the trainees are responsible for allof the activities. CPE provider observation and

involvement take place only when necessary.

This approach has proven to be very effective intransferring CPE skills to trainees. Currently, thetraining process is scheduled over a four to six-month

period. It is noted that in addition to the trainingactivities, a quality CPE must be provided to the

water utility. Because of this expectation, the numberof participants that can be trained while stillcompleting the CPE must be limited to about four tosix people.

8.2.2 CTA Training Approach

Participation in the CPE training, as described in theprevious section, is considered a prerequisite toparticipation in CTA training. Training for personnelto implement CTAs has followed a format similar tothe one used for CPE training. CTA providers can be

used to progressively transfer skills to traineesthrough the conduct of actual CTA activities. Thedifficulty with this approach is the fact that the CTAtypically occurs over a 6 to 18-month period. Also,routine telephone contact with the facility can only beeffectively implemented by one person. The currenttraining approach consists of CTA provider andtrainee involvement at site visits, with the providersupplying technical assistance to a designatedtrainee who maintains routine contact with the utilitypersonnel. The CTA provider utilizes telephone callsand exchange of materials (e.g., telephone memos,operations guidelines, plant data) to maintain traineeinvolvement. Although the approach and timecommitment limit the number of trainees involved,effective transfer of CTA skills has been achieved.

A key component of CTA training is the emphasis onproviding problem solving and priority settingcapability to the utility staff. Using this approach, thetrainees must learn not to lead with theirtroubleshooting skills but rather to recognize how toutilize situations to enhance utility priority setting andproblem solving skills. This does not mean that CTAproviders do not give technical or administrativeguidance when necessary; they only use theseactivities when they are absolutely necessary to

accomplish the long term transfer of capability to theutility staff and administration.


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Table 8-1. Training Approach to Achieve Transfer of CPE Skills

Training

Activity

CPE Provider Role Trainee Role

CCP Seminar(1 day)

Present CPE seminar Participate in seminar

First CPE(3-4 days)

Conduct kick-off meeting

Facilitate data collection

Conduct special studies

Conduct interviews

Facilitate information exchange with team

Prepare exit meeting materials

Conduct exit meeting

Facilitate feedback session with team

Prepare final report

Observe kick-off meeting

Participate in data collection

Participate in special studies

Observe interviews

Review exit meeting materials

Observe exit meeting

Review final report

Second CPE(3-4 days)




Conduct interviews


Finalize exit meeting materials

Facilitate exit meeting


Review draft report

Participate in kick-off meeting


Participate in special studies

Participate in interviews


Participate in exit meeting

Prepare final report

Third CPE(3-4 days)

Observe kick-off meeting


Observe special studies

Participate in interviews

Review exit meeting materials

Observe exit meeting


Review draft report




Conduct interviews



Conduct exit meeting

Prepare final rep

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