EXPLANATION OF THIS DOCUMENT 

PLEASE READ 

This is a draft of the Proposed Revised Total Coliform Rule Assessments and Corrective 

Actions Guidance Manual (Proposed RTCR A/CA GM). As such, there are a couple of things 

readers must keep in mind: 

• This was developed in response to stakeholders’ request. Stakeholders requested that a 

draft of the guidance manual be available during the public comment period of the 

Proposed Revised Total Coliform Rule (RTCR) to help them better prepare their 

comments on the proposed rule. 

• This is based on the requirements of a proposed rule. Between now and when the rule is 

finalized, the requirements may change depending on the comments EPA receives on the 

proposed rule during the public comment period. Accordingly, EPA will make the 

necessary changes to the guidance manual to reflect the new requirements of the final 

rule. 

• EPA is not taking any comments on the proposed rule via this draft guidance manual. 

Any comments on the proposed RTCR must be made through www.regulations.gov

(search for Docket number EPA-HQ-OW-2008-0878). The Federal Register notice for 

the proposed rule also includes additional methods for submitting comments on the 

proposed rule (75 FR 40926, July 14, 2010). 

EPA is interested in obtaining stakeholder input in further developing a guidance manual that 

would be of most use to public water systems and primacy agencies. EPA, therefore, welcomes 

comments on any aspect of the draft Proposed RTCR A/CA GM (e.g., formatting, organization, 

content, etc.), but specifically requests comment on the following: 

• Should systems be encouraged to submit assessment forms electronically? 

• Are there other causes of total coliforms/E. coli contamination that should be addressed 

in this document? 

• Are there any other potential corrective actions that have not been noted? 

• Are there other examples of assessment in Appendix B that people would like to see 

discussed instead? 

• Should any other AWWA Standards (or other references) be included? Are there ones 

that need to be deleted? 

• Should EPA consider revising the example assessment forms in Appendix A? If so, 

please provide suggestions for improvements/changes to the forms. 

Please submit your comments to prtcr_acaguide@epa.gov by November 30, 2010. 

Proposed Revised Total Coliform Rule August 2010 

Assessments and Corrective Actions Guidance Manual 

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 PROPOSED REVISED TOTAL COLIFORM 

 RULE 

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Manual 

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Office of Water (4607M) 

EPA 815-D-10-001 

August 2010 

www.epa.gov/safewater 
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DISCLAIMER 

This manual is intended to provide information to assist public water systems in 

complying with Level 1 and Level 2 assessment and corrective action requirements under the 

proposed Revised Total Coliform Rule. 

This guidance is not a substitute for applicable legal requirements, nor is it a regulation 

itself. Thus, it does not impose legally-binding requirements on any party, including EPA, 

States, or the regulated community. While EPA has made every effort to ensure the accuracy of 

the discussion in this guidance, the obligations of the regulated community are determined by 

statutes, regulations, or other legally binding requirements. In the event of a conflict between the 

discussion in this document and any statute or regulation, the statute or regulation would be 

binding. 

Interested parties are free to raise questions and objections to the guidance and the 

appropriateness of using it in a particular situation. 

 Although this manual describes suggestions for complying with proposed RTCR 

requirements, the guidance presented here may not be appropriate for all situations, and 

alternative approaches may provide satisfactory performance. 

Mention of trade names or commercial products does not constitute an EPA endorsement 

or recommendation for use. 

Questions regarding this document should be addressed to: 

Julie Javier 

U.S. EPA Office of Ground Water and Drinking Water 

Standards and Risk Management Division 

1200 Pennsylvania Avenue, N.W. 4607M 

Washington, DC 20460 

Javier.Julie@epa.gov 

Phone: 202-564-2335 

Fax: 202-564-3767 
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ACKNOWLEDGMENTS 

• American Water Works Association 

• Association of State Drinking Water Administrators 

• Association of Metropolitan Water Agencies 

• New Hampshire Department of Environmental Services 

• California Department of Public Health 

• Park Water Company 
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CONTENTS 

1. Introduction and Scope of this Manual .............................................................................................. 1-1

1.1 Organization of Document ......................................................................................................... 1-1

1.2 Nature of Microbial Indicators ................................................................................................... 1-2

1.3 Occurrence of Fecal Contamination and Waterborne Pathogens ............................................... 1-2

1.4 Causes of Coliforms and E. coli in the Distribution System ...................................................... 1-3

1.5 Other Relevant Guidance Documents ........................................................................................ 1-5

2. Summary of the Proposed Revised Total Coliform Rule ................................................................... 2-1

3. Assessments ....................................................................................................................................... 3-1

3.1 Sanitary Defects ......................................................................................................................... 3-2

3.2 Level 1 Assessments .................................................................................................................. 3-2

3.3 Level 2 Assessments .................................................................................................................. 3-3

3.4 Assessment Forms ..................................................................................................................... 3-6

3.5 Timeline for Assessments and Corrective Actions .................................................................... 3-7

3.6 Assessment Elements ................................................................................................................. 3-7

3.6.1 Operational Data Review (Questions 1 and 2) ........................................................... 3-7

3.6.2 Sample Site and Protocol Evaluation (Questions 3 and 4) ....................................... 3-13

3.6.3 Water System Component Evaluations (Questions 5 to 10) .................................... 3-14

3.7 Qualifications of Assessors ...................................................................................................... 3-19

3.7.1 Level 1 Assessors ..................................................................................................... 3-20

3.7.2 Level 2 Assessors ..................................................................................................... 3-20

3.8 Assessments and Sanitary Surveys .......................................................................................... 3-21

4. Corrective Actions ............................................................................................................................. 4-1

4.1 Common Causes ........................................................................................................................ 4-1

4.2 Common Corrective Actions ..................................................................................................... 4-2

4.2.1 Disinfection ................................................................................................................ 4-5

4.2.2 Flushing ...................................................................................................................... 4-6

4.2.3 Replacement / Repair of Distribution System Components ....................................... 4-6

4.2.4 Maintenance of Adequate Pressure ............................................................................ 4-9

4.2.5 Maintenance of Appropriate Hydraulic Residence Time ......................................... 4-11

4.2.6 Maintenance of Storage Facility .............................................................................. 4-13

4.2.7   Implementation or Upgrade of a Cross-connection Control and Backflow Prevention 

Program .................................................................................................................. ..4-14

4.2.8 Sampler Training ...................................................................................................... 4-15

4.2.9 Addition or Upgrade of On-line Monitoring and Control ........................................ 4-15

4.2.10 Addition of Security Measures................................................................................. 4-16

4.2.11 Development and Implementation of an Operations Plan ....................................... 4-16

4.3 Best Practices ........................................................................................................................... 4-17

4.4 Simultaneous Compliance Issues ............................................................................................. 4-19

5. References .......................................................................................................................................... 5-1

Appendix A ...................................................................................................... Example Assessment Forms 

Appendix B ....................................................................................... Examples of Completed Assessments 

Appendix C ................................................................... Common Sanitary Defects and Corrective Actions

Appendix D ......................................................... Industry Standards for Operating a Public Water System 
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ACRONYMS 

AIP Agreement in Principle 

AMWA Association of Metropolitan Water Agencies 

APHA American Public Health Association 

ASDWA Association of State Drinking Water Administrators 

AWWA American Water Works Association 

AWWARF American Water Works Association Research Foundation 

CCCBFP Cross-Connection Control and Backflow Prevention 

CFR Code of Federal Regulations 

CWS Community Water Systems 

DBP Disinfection Byproducts 

EC E. coli

EC+ E. coli-Positive 

EPA Environmental Protection Agency 

FR Federal Regulations 

GW Ground Water 

GWR Ground Water Rule 

GWUDI Ground Water Under the Direct Influence of Surface Water 

HAA5 Haloacetic Acids (5) 

HPC Heterotrophic Plate Count 

HRT Hydraulic Residence Time 

IESWTR Interim Enhanced Surface Water Treatment Rule 

MCL Maximum Contaminant Level 

MCLG Maximum Contaminant Level Goal 

 NCWS Non-community Water System 

NPS Nominal Pipe Size 

O&M Operation and Maintenance 

PN Public Notification 

PWS Public Water System 

RTCR Revised Total Coliform Rule 

SCADA Supervisory Control And Data Acquisition 

SOP Standard Operating Procedures 

TC Total Coliforms 

TC+ Total Coliform-Positive 

 TCR Total Coliform Rule 

TCRDSAC Total Coliform Rule / Distribution System Advisory Committee 

TT Treatment Technique 

TTHM Total Trihalomethanes 

US United States 

 USEPA United States Environmental Protection Agency 
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Proposed Revised Total Coliform Rule 1-1 August 2010 

Assessments and Corrective Actions Guidance Manual 

1 1. Introduction and Scope of this Manual 

2

3

4 Under the proposed Revised Total Coliform Rule (RTCR) (USEPA 2010b), a public 

5 water system (PWS) that is vulnerable to microbial contamination (as indicated by its monitoring 

6 results) is required to conduct assessment and corrective action of the system to identify and 

correct any sanitary defects1 7 in the distribution system or treatment processes. This document 

8 provides PWSs with guidance on implementing the assessment and corrective action 

9 requirements of the proposed RTCR. 

10

11 1.1 Organization of Document 

12

13 The document is organized as follows: 

14

15 • Chapter 1 – Introduction and Scope of this Manual. This chapter introduces the 

16 guidance manual, summarizes each section of the document, discusses the nature of 

17 microbial indicators and their relation to waterborne pathogens, discusses the causes 

18 of coliforms and E. coli in the distribution system, and provides a description of other 

19 relevant guidance documents and that may be useful to the reader. 

20

21 • Chapter 2 – Summary of the Proposed Revised Total Coliform Rule. This 

22 chapter summarizes the requirements of the proposed RTCR.

23

24 • Chapter 3 – Assessments. This chapter presents a detailed overview of the Level 1 

25 and Level 2 assessment requirements under the proposed RTCR and provides 

guidance to assist PWSs and States2 26 in the implementation of these requirements. 

27 The chapter also includes discussions on the differences between Level 1 and Level 2 

28 assessments; the elements of assessments; assessment forms; sources of data or 

29 information for completing assessment forms and recommendations on how systems 

30 should complete assessments given system attributes (e.g., system size, type, 

31 disinfection status, etc.); and qualifications of assessors. 

32

33 • Chapter 4 – Corrective Action. This chapter discusses requirements and provides 

34 guidance related to the identification and correction of sanitary defects, particularly 

35 those in the distribution system. It also provides guidance related to actions that 

36 could be taken regardless of the outcome of the assessments. 

37

38 • Appendix A – Example Assessment Forms 

39

40 • Appendix B – Examples of Completed Assessments 

                                                           

1

 A defect that could provide a pathway of entry for microbial contamination into the distribution system or that is indicative of a 

failure or imminent failure in a barrier that is already in place. Proposed RTCR § 141.851. See Chapter 3.1 of this document for 

a more detailed discussion of sanitary defects. 

2

 In this document, “State” is used to generally refer to the primacy agency, whether it be the State agency, the Tribal 

government, or EPA. A primacy agency is the entity that has the primary responsibility for administrating and enforcing 

regulations under the Safe Drinking Water Act (SDWA) in a given jurisdiction. In many cases, the State agency is the primacy 

agency. 
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1

2 • Appendix C – Common Sanitary Defects and Corrective Actions 

3

4 • Appendix D – Industry Standards for Operating a Public Water System 

5

6 1.2 Nature of Microbial Indicators 

7

8 The proposed RTCR aims to increase public health protection through the reduction of 

9 potential pathways of entry for fecal contamination into the distribution system. Since these 

10 potential pathways represent vulnerabilities in the distribution system whereby fecal 

11 contamination and/or waterborne pathogens, including bacteria, viruses and parasitic protozoa 

12 could possibly enter the system, the reduction of these pathways in general should lead to 

13 reduced exposure and associated risk from these contaminants. Fecal contamination and 

14 waterborne pathogens can cause a variety of illnesses, including acute gastrointestinal illness 

15 (AGI) with diarrhea, abdominal discomfort, nausea, vomiting, and other symptoms. As stated 

16 earlier, under the proposed RTCR, a PWS that is vulnerable to fecal contamination (as indicated 

17 by its monitoring results for total coliforms and E. coli) is required to conduct an assessment of 

18 the system to identify and correct any sanitary defects. 

19

20 Under the proposed RTCR, EPA uses total coliforms as indicators of the integrity of the 

21 distribution system, and E. coli as an indicator of the presence of fecal contamination. 

22

23 Total coliforms are a group of closely related bacteria that, with few exceptions, are not 

24 harmful to humans. Coliforms are abundant in the feces of warm-blooded animals, but can also 

25 be found in aquatic environments, in soil, and on vegetation. Coliform bacteria may be 

26 transported to surface water by run-off or to ground water by infiltration. Total coliforms are 

27 common in ambient water and may be injured by environmental stresses such as lack of 

28 nutrients, and water treatments such as chlorine disinfection, in a manner similar to most 

29 bacterial pathogens and many viral enteric pathogens (including fecal pathogens). EPA 

30 considers total coliforms to be a useful indicator that a potential pathway exists through which 

31 fecal contamination can enter the distribution system. The absence (versus the presence) of total 

32 coliforms in the distribution system indicates a reduced likelihood that fecal contamination 

33 and/or waterborne pathogens are occurring in the distribution system. 

34

35 Under the proposed RTCR, each total coliform-positive sample is assayed for E. coli. E. 

36 coli is a more restricted group of coliform bacteria that almost always originate in the human or 

37 animal gut (Edberg et al. 2000). Thus, E. coli is used as an indicator of fecal contamination. 

38

39 1.3 Occurrence of Fecal Contamination and Waterborne Pathogens 

40

41 Fecal contamination is a very general term that includes all of the organisms found in 

42 feces, both pathogenic and nonpathogenic. Fecal contamination can occur in drinking water both 

43 through use of contaminated source water without sufficient treatment as well as direct intrusion 

44 of fecal contaminants into the drinking water distribution system. Lieberman et al. (1994) 

45 discuss the general association between fecal contamination and waterborne pathogens. Biofilms 

46 in distribution systems may harbor waterborne bacterial pathogens and accumulate enteric 

47 viruses and parasitic protozoa (Skraber et al. 2005; Helmi et al. 2008). Waterborne pathogens in 

48 biofilms may have entered the distribution system as fecal contamination from humans or 

49 animals. 
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1

2 Co-occurrence of indicators and waterborne pathogens is difficult to measure. The 

3 analytical methods approved by EPA to assay for E. coli are able to detect indicators of fecal 

4 contamination but do not specifically identify most of the pathogenic E. coli strains. Specialized 

5 assays and methods are used to identify waterborne pathogens, including pathogenic E. coli such 

6 as E. coli O157:H7, which is the primary cause of hemolytic uremic syndrome (HUS) in the 

7 United States (Rangel et al. 2005). Therefore, an E. coli-positive monitoring result is an 

8 indicator of fecal contamination (Edberg et al. 2000) but is not necessarily a measure of 

9 waterborne pathogen occurrence. However, studies have shown that there is a general 

10 association between fecal contamination and waterborne pathogens (Lieberman et al. 1994; 

11 Lieberman et al. 2002). Hence, E. coli is a meaningful indicator for fecal contamination and the 

12 potential presence of associated pathogen occurrence. 

13

14 1.4 Causes of Coliforms and E. coli in the Distribution System 

15

16 There are numerous factors that can contribute to the presence of coliforms and E. coli in 

17 the distribution system. Coliform bacteria may be present in the distribution system if three 

18 conditions simultaneously occur: 

19

20 1. A source of coliform bacteria; 

21 2. A pathway into the distribution system or a breach in the system’s physical integrity; 

22 and 

23 3. A mechanism that allows coliform bacteria to be carried on this pathway into the 

24 distribution system or that allows bacteria within biofilms, corrosion tubercles or 

25 sediment to enter the water. 

26

27 Sources of coliform bacteria can include: 

28

29 • Soil and Water Surrounding Pipes – Coliform bacteria are common in the soil and 

30 water surrounding pipes, valves, and other distribution system infrastructure. 

31 • Biofilms and Microbial Growth - Coliforms may attach to or become enmeshed in 

32 biofilms on pipe walls in distribution systems, where they are protected from 

33 disinfectants. Over time, these coliforms (including their associated pathogens) may 

34 detach or slough from biofilms, causing persistent detections and even waterborne 

35 disease. 

36 • Corrosion Tubercles - A number of cases have been documented showing the 

37 presence of coliform bacteria present within corrosion tubercles. 

38 • Customer Connections - Customer connections and premise plumbing, such as the 

39 service line connections to schools, hospitals, public and private housing, and other 

40 buildings, can be the source of coliform bacteria when a backflow event has occurred 

41 and water and contamination from the building pipes are drawn back into the public 

42 water distribution system, due to a change in pressure. 

43 • Materials Used in the Distribution System - In some instances, materials used in the 

44 distribution system can result in the presence of total coliforms through 

45 contamination of the materials prior to installation. Some materials may also support 

46 the growth of coliforms by providing nutrients for microbial growth. 
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1 • Sediments - Sediment accumulation can provide a habitat for microbial growth in a 

2 distribution system. Furthermore, the sediments can protect the microbes from 

3 disinfectants. 

4

5 Pathways through which total coliform bacteria can enter the distribution system can be: 

6

7 • Finished Water Storage Facility Deficiencies - Storage tank deficiencies, such as 

8 vents without screens, inadequate hatches, access hatches that are not locked, physical 

9 openings in storage tank roofs, and lack of a cover, can result in the entry of 

10 contaminants. Microorganisms can also be introduced into underground storage 

11 facilities from surface water or ground water infiltration or runoff. 

12 • Unprotected Cross Connections - A cross connection is a pathway whereby a 

13 connection exists between a non-potable water source and a potable source (e.g., the 

14 public water system). Backflow through a cross connection is the mechanism that 

15 allows non-potable water to enter the water distribution system. 

16 • Intrusion - Leaks or small holes in the pipe can provide a pathway for contaminants 

17 outside of a pipe to enter the distribution system during low and negative pressure 

18 events (termed intrusion). Points through which intrusions can occur also include 

19 pipe fracture cracks, leaking joints, submerged air-vacuum /air-release valves and 

20 deteriorating seals. 

21 • Improper Main Installation, Repair, or Replacement - Main installation, repair, or 

22 replacement can result in a loss of pressure and exposure of the pipe interior to 

23 contaminated soil and runoff. If sanitary procedures are not followed, contaminants 

24 can be introduced into the pipes during the main break repair process. 

25

26 Mechanisms that allow coliform bacteria to enter the distribution system (assuming a 

27 source of contaminants and a pathway are present) or that allow bacteria to proliferate in the 

28 distribution system include the following: 

29

30 • Weather-Related Events - A range of different weather-related events can contribute 

31 to the increase of total coliforms, and sometimes fecal indicators in source waters. In 

32 other cases, coliforms may enter the distribution system more directly. Types of 

33 weather-related events that have been attributed to indicator positive samples include 

34 significant rainfall events, droughts, and excessively warm or cold weather. 

35 • Treatment Breakthrough - Failure of the treatment barrier can lead to presence of 

36 coliforms in the distribution system. 

37 • Backflow – Backflow that allows the non-potable water to enter the potable system 

38 can occur either because of reduced pressure in the distribution system (termed 

39 backsiphonage) or the presence of increased pressure in the non-potable system 

40 (termed backpressure). 

41 • Hydraulic Conditions - Contaminant intrusion may occur if a very low or negative 

42 pressure occurs within the pipe. Low pressure conditions in the distribution system 

43 can also allow a flow reversal or backflow of non-potable water to enter the system 

44 from a cross connection or other source such as intrusion. 

45 • Operations - Sudden velocity or flow direction changes during operational activities 

46 within a distribution system can result in the release of biofilms, scales, or sediments 

47 with microbial contamination These velocity and flow changes are sometimes related 

48 to fire fighting, valve exercising, and changing from one source to another. 
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Proposed Revised Total Coliform Rule 1-5 August 2010 

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1 • Maintenance Practices – Maintenance practices such as flushing and line cleaning can 

2 affect the distribution system water quality in a negative manner if not conducted 

3 properly and improper flushing can result in moving a contaminant further into the 

4 distribution system. 

5 • Retention Times - Long retention time in the distribution system can reduce the levels 

6 of disinfectant residual and allow for the deposition and accumulation of sediment. 

7 • Presence of Nutrients - Some materials or system operations can introduce nutrients 

8 such as carbon, nitrogen, and phosphorus to the distribution system that may support 

9 growth of total coliform bacteria. 

10

11 Additional information on the causes of coliforms and E. coli in the distribution system 

12 can be found in a series of issue papers and white papers located at 

13 http://www.epa.gov/safewater/disinfection/tcr/regulation_revisions.html 

14

15 1.5 Other Relevant Guidance Documents 

16

17 The reader can refer to the following guidance manuals and documents for more 

18 information that may be helpful in complying with the assessment and corrective action 

19 requirements of the proposed RTCR. 

20

21 • Ground Water Rule Corrective Actions Guidance Manual (EPA 815-R-08-011; 

22 November 2008) 

23 http://www.epa.gov/safewater/disinfection/gwr/pdfs/guide_gwr_correctiveaction.pdf 

24 This guide provides guidance in meeting the corrective action requirements of the 

25 Ground Water Rule. It provides assistance in determining the information that should 

26 be included in a public water system’s (PWS’s) corrective action plan and assists 

27 States and PWSs to select and implement corrective actions in response to significant 

28 deficiencies identified during a sanitary survey or in response to fecal contamination 

29 of the source water. 

30

31 • Sanitary Survey Guidance Manual for Ground Water Systems (EPA 815-R-08-

32 015; October 2008) 

33 http://www.epa.gov/safewater/disinfection/gwr/pdfs/guide_gwr_sanitarysurvey.pdf 

34 This guide provides a brief review of the sanitary survey regulatory provisions for 

35 ground water systems, give specific examples of what constitutes a significant 

36 deficiency, and provide a checklist of elements that should be evaluated during the 

37 course of a sanitary survey inspection. 

38

39 • Guidance Manual for Conducting Sanitary Surveys of Public Water Systems; 

40 Surface Water and Ground Water Under the Direct Influence (GWUDI) (EPA41 815-R-99-016; April 1999) 

42 http://www.epa.gov/safewater/mdbp/pdf/sansurv/sansurv.pdf 

43 This guide provides guidance on how to conduct sanitary surveys of surface water 

44 systems and ground water under the direct influence (GWUDI) of surface water 

45 systems. It explains the elements of the sanitary survey and presents general 

46 guidelines for evaluating the important components of each element. 

47

48
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1 EPA is also planning to revise the following documents for the final RTCR: 

2

3 • Total Coliform Rule: A Quick Reference Guide (EPA 816-F-01-035, September 

4 2001) 

5 http://www.epa.gov/safewater/disinfection/tcr/pdfs/qrg_tcr_v11.pdf

6 This two page guide provides the highlights of key rule requirements such as routine 

7 and repeat sampling requirements, routine monitoring frequencies, compliance and 

8 violation information, and public notification and reporting requirements. 

9

10 • A Small Systems Guide to the Total Coliform Rule: Monitoring Drinking Water 

11 to Protect Public Health (EPA 816-R-01-017A, June 2001) 

12 http://www.epa.gov/safewater/disinfection/tcr/pdfs/guide_tcr_smallystemsguide.pdf

13 This guide provides information for community water systems that serve fewer than 

14 3,300 people. The guide describes the importance of monitoring drinking water to 

15 ensure its quality and protect public health and the monitoring that is required under 

16 the Total Coliform Rule. It outlines the steps water systems must take if their 

17 samples indicate the presence of coliform bacteria and a worksheet to help keep track 

18 of monitoring and follow-up actions. 

19

20 • Total Coliform Rule: A Handbook for Small Noncommunity Water Systems 

21 serving less than 3,300 persons: One of the Simple Tools for Effective 

22 Performance (STEP) Guide Series (EPA 816-B-06-001, July 2006) 

23 http://www.epa.gov/safewater/disinfection/tcr/pdfs/stepguide_tcr_smallsys-3300.pdf

24 This guide provides information for non-community water systems that serve fewer 

25 than 3,300 people. The guide describes the monitoring that is required under the 

26 Total Coliform Rule. It outlines the steps water systems must take if their samples 

27 indicate the presence of coliform bacteria and a worksheet to help keep track of 

28 monitoring and follow-up actions. 

29

30 • Total Coliform Rule: A Handbook for Small Non-community Water Systems 

31 serving 1,000 Persons or Less

32 A planned guide specifically for systems serving 1,000 persons or fewer given the 

33 reduced monitoring requirements that are particular to this group, possibly including 

34 one page pullouts and other simple tools for compliance assistance. 

35
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1 2. Summary of the Proposed Revised Total Coliform Rule 

2

3

4 The proposed RTCR maintains and strengthens the objectives of the 1989 Total Coliform 

5 Rule (TCR) and is consistent with the recommendations in the Agreement in Principle (AIP) 

signed by the Total Coliform Rule Distribution System Advisory Committee (TCRDSAC)3 6 . The 

7 rule objectives are: (1) to evaluate the effectiveness of treatment, (2) to determine the integrity of 

8 the distribution system, and (3) to signal the possible presence of fecal contamination. The 

9 proposed revision better addresses these objectives by requiring systems that may be vulnerable 

10 to fecal contamination (as indicated by their monitoring results) to do an assessment, to identify 

whether any sanitary defects4 11 are present, and to correct the defects. Therefore, EPA anticipates 

12 greater public health protection under the proposed RTCR compared to the 1989 TCR because of 

13 its more preventive approach to identifying and fixing problems that affect or may affect public 

14 health. The following table gives an overview of the key provisions of the proposed RTCR. For 

the full requirements of the proposed RTCR, please refer to 40 CFR5 15 Part 141, Subpart Y. 

16

17 Table 2.1 Summary of Proposed RTCR Requirements 

Element Proposed RTCR requirements

Rule construct 

§§ 141.52, 141.63, 

141.854, 141.859 

• The proposed RTCR sets an E. coli (EC) maximum contaminant level goal (MCLG) 

of zero, and an EC maximum contaminant level (MCL) and a coliform treatment 

technique (TT) based on total coliform (TC) and/or EC monitoring results. 

• Compliance is based on the presence or absence of TC and EC and is determined each 

calendar month the PWS serves water to the public (or each calendar month that 

sampling occurs for systems on reduced monitoring). See sections on “Assessment” 

and “Violations and Public Notification (PN)” in this table for conditions when the 

coliform TT and EC MCL are violated. 

• Assessment and corrective action (if necessary) are required if PWS has a coliform 

treatment technique trigger. See sections on “Assessment” and “Corrective Action” in 

this table. 

Transition from the 

1989 TCR to the 

RTCR 

§§ 141.854 to 141.857

• PWSs continue on their existing TCR monitoring schedule when the RTCR is 

effective. 

• Ground water (GW) systems serving 1,000 or fewer persons remain on their TCR 

schedule unless or until the conditions occur as described below or unless otherwise 

directed by the State. 

o Non-community water systems (NCWSs) on quarterly/annual monitoring remain 

on that schedule unless/until they have an event that triggers increased monitoring. 

See the section on “Increased Monitoring (NCWS)” in this table. 

o Community water systems (CWSs) on reduced monitoring remain on that schedule 

unless/until they have an event that triggers them to go to routine monitoring. See 

the section on “Return to Routine Monitoring (CWS)” in this table. 

o Monitoring schedules will be evaluated during the “special monitoring evaluation” 

conducted by the State as part of the periodic sanitary survey. 

                                                           

3

 For more information on the AIP and the TCRDSAC, please go to 

http://www.epa.gov/safewater/disinfection/tcr/regulation_revisions_tcrdsac.html 

4

 See Chapter 3.1 of this document. 

5

 Code of Federal Regulations 
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Element Proposed RTCR requirements

Routine Monitoring 

§§ 141.853 to 141.858 

• Total coliform samples must be collected at sites which are representative of water 

quality throughout the distribution system according to a written sample siting plan 

subject to State review and revision. 

• Samples must be collected at regular time intervals throughout the month except some 

small systems may collect them on the same day. 

• The number of monthly samples is based on population served. Reduced monitoring 

is available for some small GW systems that meet certain criteria. See the section on 

“Reduced Monitoring” in this table. 

• Systems on less than monthly monitoring may be triggered to increase their 

monitoring if certain conditions occur. See the sections on “Increased Monitoring 

(NCWS)” and “Return to Routine Monitoring (CWS)” in this table. 

• Each total coliform-positive routine sample must be tested for the presence of E. coli

and three repeat samples must be taken. 

• Monitoring provisions are included for seasonal systems,6

 which require them to 

monitor monthly, have a sample siting plan, and to demonstrate State-approved startup procedure. Reduced monitoring may be available for some small seasonal GW 

systems that meet certain criteria. See the section on “Reduced Monitoring” in this 

table. 

Reduced Monitoring 

§§ 141.854, 141.855 

• NCWSs serving 1,000 or fewer people (GW) – can be eligible to reduce their routine 

monitoring of 1 sample per quarter (i.e., quarterly) to no less than 1 sample per year 

(i.e., annual) if they meet the following criteria: 

o Most recent sanitary survey shows that system is free of sanitary defects, has a 

protected water source, and meets approved construction standards; 

o Clean compliance history7

 for a minimum of 12 months; 

o An annual site visit by the State (or a Level 2 assessment by party approved by 

State) within the last 12 months and correction of all identified sanitary defects. 

System must have an annual site visit (or its equivalent) every year thereafter to 

remain on annual monitoring. 

• Seasonal systems serving 1,000 or fewer people (GW) can be eligible for reduced 

monitoring by having an approved sample site plan that designates the time period for 

monitoring based on demand and vulnerability. 

o For quarterly monitoring the seasonal system must also have a sanitary survey or 

site visit or Level 2 assessment within last 12 months; a protected water source; a 

clean compliance history for a minimum of 12 months, and be free of sanitary 

defects. 

o To reduce to 1 sample per year, the seasonal system must meet the criteria specified 

above for quarterly monitoring and have in place or adopt one or more additional 

enhancements to barriers to contamination (cross connection control, certified 

operator, meet disinfection criteria, maintenance of at least 4-log removal or 

inactivation of viruses, other equivalent enhancements). 

• CWSs serving 1,000 or fewer people (GW) – may reduce their routine monitoring (1 

sample per month) to 1 sample per quarter if it meets the following criteria: 

                                                           

6

 A seasonal system is defined as a non-community water system that is operated in three or fewer calendar quarters per year. 

7 A record of no maximum contaminant level (MCL) violations under 40 CFR 141.63; no monitoring violations under 40 CFR 

141.21 or subpart Y; and no coliform treatment technique trigger exceedances or coliform treatment technique violations under 

subpart Y.
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Element Proposed RTCR requirements

o State certified operator; 

o Most recent sanitary survey shows that system is free of sanitary defects (or has an 

approved plan and schedule to correct them), has a protected water source, and 

meets approved construction standards; 

o Clean compliance history for a minimum of 12 months; 

o Meets at least one of the following criteria: annual site visit by the State or a 

voluntary Level 2 assessment by a party approved by the State and correction of all 

identified sanitary defects (or an approved plan schedule to correct them); cross 

connection control; meet disinfection criteria; maintenance of at least 4-log removal 

or inactivation of viruses; other equivalent enhancements to water systems as 

approved by the State. 

• No other systems are eligible for reduced monitoring. 

Increased Monitoring 

(NCWS) 

§ 141.854 

• NCWSs serving 1,000 or fewer people (GW), including seasonal systems, increase 

from quarterly or annual monitoring to monthly monitoring if one of the following 

occurs: 

o Triggered Level 2 assessment or a 2nd Level 1 assessment in 12 months; 

o EC MCL violation; 

o Coliform TT violation; or 

o Two monitoring violations within 12 months if on quarterly monitoring or one 

monitoring violation if on annual monitoring.

Return to Routine 

Monitoring (CWS) 

§ 141.855

• CWSs serving 1,000 or fewer people (GW) on quarterly monitoring return to monthly 

monitoring based on same criteria above for NCWSs serving 1,000 or fewer people 

(GW). 

Return to Reduced 

Monitoring (After 

Being Triggered to 

Increased Monitoring) 

(NCWS) 

§ 141.854 

• NCWSs serving 1,000 or fewer people (GW) must meet the following criteria to return 

to routine quarterly monitoring after being triggered to increased monitoring: 

o Within the last 12 months, system must have completed a sanitary survey or a site 

visit by the State or a voluntary Level 2 assessment by a party approved by the 

State, must be free of sanitary defects, and must have a protected water source; and 

o Clean compliance history7

 for a minimum of 12 months. 

• NCWSs serving 1,000 or fewer people (GW) must meet the following criteria to return 

to reduced annual monitoring in addition to meeting the criteria for returning to routine 

quarterly monitoring: 

o An annual site visit by the State or a voluntary Level 2 assessment and correction of 

all identified sanitary defects; and 

o Adoption of one or more additional enhancements to the water system barriers to 

contamination (cross connection control, certified operator, meet disinfection 

criteria, maintenance of at least 4-log removal or inactivation of viruses, other 

equivalent enhancements). 

Return to Reduced 

Monitoring (After 

Being Triggered to 

Return to Routine 

Monitoring) (CWS) 

§ 141.855 

• CWSs serving 1,000 or fewer people (GW) must meet the same criteria for qualifying 

for reduced quarterly monitoring. See section on “Reduced Monitoring” for CWSs 

serving 1,000 or fewer people (GW) in this table. 
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Element Proposed RTCR requirements

Repeat Monitoring 

§ 141.858 

• All PWSs must take 3 repeat samples after a TC+ sample at locations specified in the 

sample siting plan. 

• For GW PWSs serving 1,000 people or fewer, a single sample can meet both the 

triggered source water requirements of the GWR and the repeat sample requirements 

of the proposed RTCR, but only if the State approves the use of the single sample to 

meet both rule requirements and the use of EC as the fecal indicator. Otherwise, the 

system must take an additional source sample to comply with the GWR. 

Additional Routine 

Monitoring 

§§ 141.854, 141.855

• A PWS taking routine samples less than monthly is required to take a minimum of 3 

routine samples the following month it serves water to the public after a TC+ sample, 

unless the State waives the requirement. 

Assessment 

§ 141.859 

• The PWS must conduct a Level 1 assessment if it exceeds any of the following 

triggers: 

o For systems taking ≥ 40 samples per month, the PWS exceeds 5.0% TC+ samples 

for the month; or 

o For systems taking < 40 samples per month, the PWS has ≥ 2 TC+ samples for the 

month; or 

o The PWS fails to take every required repeat sample after any single routine TC+ 

sample. 

• The PWS must ensure that a Level 2 assessment is conducted either by the State or a 

State -approved party (which could include a qualified PWS employee(s)) if it exceeds 

any of the following triggers: 

o The PWS has an E. coli MCL violation. 

o The PWS has a second Level 1 trigger within a rolling 12-month period, or in 2 

consecutive years for systems on annual monitoring. 

• The system must complete the assessment as soon as practical after failure to take a 

repeat sample or after notification of results (i.e., after it determines that an assessment 

trigger has been exceeded). 

• Assessment results and description of corrective action(s) taken will be submitted to 

the State within 30 days after determination of exceeding the trigger. The State must 

determine if the assessment is sufficient, whether or not a sanitary defect is found. 

Corrective Action 

§ 141.859 

• System must correct all sanitary defects found in the assessment. 

• For corrections not completed by the time the assessment form is submitted, the 

systems must be in compliance with a State-determined schedule and must notify the 

State when completed. 

Violations and Public 

Notification (PN) 

§§ 141.202, 141.203, 

141.204, 141.860, 

141.861 

• EC MCL violation – when any of the following occurs; requires Tier 1 PN. 

o EC+ repeat sample following a TC+ routine sample 

o TC+ repeat sample following an EC+ routine sample 

o Failure to take all required repeat samples following an EC+ routine sample 

o Failure to test for EC when any repeat sample is TC+ 

• Coliform TT violation – occurs when a PWS fails to conduct required assessment 
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Element Proposed RTCR requirements

and/or corrective action; requires Tier 2 PN. 

• Monitoring violation – occurs when PWS fails to take every required routine or 

additional routine sample in a compliance period, or fails to analyze for EC following a 

TC+ routine sample; requires Tier 3 PN. 

• Reporting violation – occurs when a PWS fails to submit a monitoring report or 

completed assessment form after a system properly conducts monitoring or 

assessment; requires Tier 3 PN. 

1

2
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1 3. Assessments 

2

3

4 The purpose of performing assessments is to enhance public health protection by 

5 identifying the presence of "sanitary defects” (defects that could provide a pathway of entry for 

6 microbial contamination into the distribution system or that are indicative of a failure or 

7 imminent failure in a barrier that is already in place). Sampling results can trigger an assessment 

8 designed to take a closer look at the system and to identify whether one or more sanitary defects 

9 are present. This is a more proactive approach than that of the 1989 TCR and will lead to the 

10 identification and correction of problems that may compromise public health. 

11

12 The RTCR includes two levels of assessments – Level 1 and Level 2 (with the Level 2 

13 assessment being more detailed than a Level 1 assessment) – to recognize the severity of the 

14 situation and the varying level of effort required for the assessment. For example, a higher level 

15 of effort is needed to diagnose a problem arising from situations of greater potential of public 

16 health concern such as repeated Level 1 triggers or an E. coli MCL violation. For either Level 1 

17 or Level 2 assessments, the PWS must assure the completion of the assessment as soon as 

18 practical after notification of their monitoring results. Having the PWS responsible for having 

19 the assessment conducted also serves to strengthen the PWS’s capacity to ensure that barriers to 

20 contamination are in place and are effective in the future. The PWS will provide the primacy 

21 agency a completed Level 1 or Level 2 assessment form within 30 days after determination of 

22 exceeding the trigger. 

23

24 The minimum elements of both Level 1 and Level 2 assessments must include a review 

25 and identification of the following: 

26

27 1. Inadequacies in sample sites, sampling protocol, and sample processing 

28 2. Atypical events that may have affected distributed water quality or indicate that 

29 distributed water quality was impaired 

30 3. Changes in distribution system maintenance and operation that may have affected or 

31 are affecting distributed water quality including water storage 

32 4. An evaluation of source water quality and treatment changes or conditions that may 

33 affect distributed water quality, where appropriate 

34 5. Existing water quality monitoring data. 

35

36 Level 1 and Level 2 assessments consider the same five minimum elements but the depth 

37 of consideration of those elements differ because of the differences in severity among the types 

38 of assessment triggers. Similarly, triggering a Level 2 assessment implies that a contamination 

39 event may be more complicated and pose a greater risk; the level of skills and qualifications 

40 expected for a Level 2 assessor should be sufficient to address the complexity and higher degree 

41 of risk. Chapters 3.2 and 3.3 describe the Level 1 and Level 2 assessments in greater detail and 

42 clarify the differences between the two. Chapter 3.5 discusses the specific items in the example 

43 assessment forms found in Appendix A. States may also tailor specific assessment elements to 

44 the size and type of the system and PWSs in turn may tailor its assessment activities based on the 

45 specific characteristics of its distribution system. 

46
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1 3.1 Sanitary Defects 

2 As mentioned previously, sanitary defects within the distribution system are defined as 

3 defects that could provide a pathway of entry for microbial contamination into the distribution 

4 system or that are indicative of a failure or imminent failure in a barrier that is already in place. 

5 Proper operation and maintenance of the distribution system is the last protective barrier to 

6 microbial contamination of drinking water. If the distribution system is breached, microbial 

7 contamination can enter the treated water and be transported to customers, potentially resulting 

8 in adverse health outcomes. Therefore it is vital to identify and correct sanitary defects to 

9 maintain distribution system integrity and proactively protect public health. 

10 Some examples of sanitary defects are holes in tanks that could allow entry of insects or 

11 small animals, breaks in pipes that could allow entry of contaminated water (especially when low 

12 pressure events occur), and cracks in well seals or casings. 

13 The goal of assessments is to provide a review of the condition of the distribution system 

14 and source water components in order to identify if a sanitary defect exists that could have 

15 caused a coliform positive sample. When performing a Level 1 or 2 assessment, the PWS may 

16 find one or more sanitary defects. Ideally, the PWS should determine if any of the sanitary 

17 defects is the likely cause of the coliform positive samples through an evaluation of data, 

18 additional sampling, and investigation of system conditions. Documentation of the PWS 

19 findings should be submitted in accordance with the primacy agency requirements. It may or 

20 may not be possible to conclusively link the coliform positive samples to a given sanitary defect 

21 due to the complexity of distribution system configuration and transport of contaminants 

22 throughout the system. Even if the defect cannot be proven to be a likely cause of coliform 

23 positive samples, the PWS must correct all sanitary defects that are found to prevent them from 

24 providing a pathway to future contamination. The PWS should work with the primacy agency to 

25 develop a schedule for correction of sanitary defects if it is not feasible to correct them 

26 immediately, which may be the case for corrective actions requiring major construction or capital 

27 improvements (e.g., replacement of a well, repairs to a storage facility). 

28

29 3.2 Level 1 Assessments 

30

31 The Level 1 assessment consists of a relatively simple examination of the system’s 

32 source water, treatment, distribution system, and relevant operational practices. The Level 1 

33 assessment is intended as a self-assessment. EPA anticipates that this will be completed by the 

34 PWS and reviewed by the primacy agency. If the primacy agency determines that the 

35 assessment is insufficient, it will consult with the PWS. 

36

37 A Level 1 assessment is triggered if sampling results in any one of the following: 

38

39 1. For systems collecting 40 or more samples per month, the PWS exceeds 5.0% total 

40 coliform-positive samples for the month; or 

41 2. For systems collecting fewer than 40 samples per month, the PWS has two or more 

42 total coliform-positive samples in the same month; or 

43 3. The PWS fails to take every required repeat sample after any single routine total 

44 coliform-positive sample. 

45

46
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1 For the Level 1 assessment, the PWS should look at conditions that could have occurred 

2 prior to the collection of the total coliform-positive sample(s). A Level 1 assessment can often 

3 be primarily completed using data on hand at the PWS and conducting limited inspections and 

4 does not necessarily include extensive new field investigations. Interviews of appropriate PWS 

5 employees can also be a valuable means of obtaining important information. Example 

6 conditions that may result in coliform-positive samples include treatment process interruptions, 

7 loss of pressure, maintenance and operation activities, wet weather events, and recent operational 

8 changes. The PWS should also consider and note the condition of system facilities, such as 

9 sample sites, distribution system, storage tanks, and source water. In addition, larger systems 

10 may want to target their assessments to specific sections of their distribution system or facilities 

11 if they find that the exceedances that triggered the assessment are clustered in one part of the 

12 system. 

13

14 PWSs must document their Level 1 assessment in an assessment form, which they must 

15 complete and submit to the primacy agency within 30 days after the PWS has determined that the 

16 trigger has been exceeded. For more discussion of the assessment forms, see Chapter 3.4 of this 

17 document. 

18

19 Identifying and correcting sanitary defects early will provide some assurance that the 

20 system has addressed the issue that may compromise public health. While the Level 1 

21 assessment is intended to be a relatively simple assessment, it should be conducted thoroughly 

22 enough to capture the possibility that there may be multiple sanitary defects. Systems should 

23 complete the entire assessment form, even if they believe they understand the apparent cause, to 

24 ensure they have a holistic picture of the overall integrity of their system and do not 

25 inadvertently overlook a sanitary defect. Ideally, a well-performed Level 1 assessment will 

26 prevent most systems from developing conditions that lead to a Level 2 assessment. 

27     

28 3.3 Level 2 Assessments 

29

30 A Level 2 assessment is a more detailed examination of the system, its monitoring 

31 program and results, and its operational practices. The elements of a Level 2 assessment are the 

32 same as those of a Level 1 assessment, but each element is investigated in greater detail. A 

33 Level 2 assessment will likely include field investigations, additional sampling and additional 

34 inspections of facilities beyond those performed in a Level 1 assessment. The level of effort and 

35 resources required to implement the Level 2 assessments will be commensurate with a more 

36 comprehensive investigation, a higher level review of available information, and may involve the 

37 engagement of additional parties and expertise. Table 3.1 presents examples of possible 

38 differences in the level of effort between a Level 1 and Level 2 assessment. 

39
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1 Table 3.1 Examples of Possible Differences in Level of Effort between Level 1 and 

2 Level 2 Assessments

3

Level 1 Effort Level 2 Effort 

• Review all monitoring results from appropriate 

areas of the distribution system for the previous 

12 months 

• Review all monitoring results from appropriate 

areas of the distribution system for the previous 

12 months 

• Conduct additional investigatory monitoring 

• Review cross connection control records for 

medium- and high-risk facilities in the area of 

the positive samples 

• Review cross connection control records for 

medium- and high-risk facilities in the area of 

the positive samples 

• Inspect backflow prevention devices in the 

medium- and high-risk facilities in the area of 

the positive samples 

• Review records of storage tank inspections • Review records of storage tank inspections 

• Inspect storage tanks that feed the area of the 

positive samples 

• Review records of inspections of wells and 

surface water source and weather events 

• Review records of inspections of wells and 

surface water source and weather events 

• Inspect wells and surface water sources 

• Interview sample collectors, distribution system 

managers, other appropriate employees 

• Interview sample collectors, distribution system 

managers, other appropriate employees 

• Consult with outside experts, professional 

engineers 

• Interview residents and businesses in the area of 

the positive samples 

• Review records of entry point and distribution 

system disinfectant levels 

• Review records of entry point and distribution 

system disinfectant levels, including historical 

seasonal changes if any 

• Conduct additional residual testing at the entry 

point and appropriate locations in the 

distribution system 

• Review records of distribution system 

maintenance, especially in the area of the 

positive samples 

• Review records of distribution system 

maintenance, especially in the area of the 

positive samples 

• Inspect on-going maintenance activities 

• Notify the State of results and discuss with the 

State as needed 

• Consult with the State about assessment plans 

and approach, especially if the assessment is 

triggered by detection of E. coli. 

• Notify the State of results and discuss with the 

State 

• Conduct on-site inspections as indicated by 

record reviews and interviews above 

• Conduct on-site inspections as indicated 

above 

4

5 If the primacy agency determines that the Level 2 assessment is insufficient, it will 

6 consult with the PWS. The primacy agency may also direct a PWS to perform an expedited 

7 action or additional actions in cases with significant potential for public health impact, such as in 

8 the case of an E. coli MCL violation. For example, the primacy agency may direct the PWS to 
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1 apply temporary disinfection while the assessment is ongoing and before the cause and source of 

2 the contamination is determined. 

3

4 A Level 2 assessment is triggered if sampling results in any one of the following: 

5

6 1. The PWS has an E. coli MCL violation; or 

7 2. The PWs triggers a second Level 1 assessment within a rolling 12-month period, 

8 unless the State has determined a likely cause for the situation that resulted in the 

9 initial Level 1 treatment technique trigger and establishes that the system has fully 

10 corrected the problem; or 

11 3. For systems with approved reduced annual monitoring, a Level 1 treatment technique 

12 trigger in two consecutive years. 

13

14 Level 2 assessments are triggered by events that either (a) pose a potential immediate 

15 acute public health threat (i.e., trigger associated with the presence of E. coli) or (b) those that do 

16 not necessarily pose an immediate acute public health threat (i.e., a second Level 1 trigger) but 

17 may still pose a potential serious health impact because of the persistence of the contamination. 

18 EPA anticipates that Level 2 assessments following triggers associated with the presence of E. 

19 coli may be more involved than the Level 2 assessments following triggers in which there is no 

20 E. coli present, given the differing potential of public health concern. 

21

22 While the Level 1 assessment is intended as a self-assessment, Level 2 assessments must 

23 be conducted by a party approved by the primacy agency due to the higher level of complexity. 

24 The party conducting the assessment could be the primacy agency itself, a third party, or the 

25 PWS where the system has staff or management with the required certification or qualifications 

26 specified by the primacy agency. Chapter 3.7.2 of this document discusses Level 2 assessor 

27 qualifications in greater detail. 

28

29 In addition to the qualifications of the assessor, there are a number of other differences in 

30 how Level 2 assessments are conducted versus Level 1 assessments. In a Level 2 assessment, 

31 the conditions that could have occurred prior to the total coliform-positive sample(s), as well as 

32 the current condition of water system facilities and system operation and maintenance, should be 

33 examined in detail, and the system should conduct a physical inspection of suspected facilities. 

34 During this examination, it is recommended that the assessor notes any atypical conditions, even 

35 if those conditions do not appear to definitively correlate with the total coliform- or E. coli36 positive samples. The assessor should review past Level 1 assessments and sanitary survey 

37 results. The assessor should also consult with others involved in operation or management of the 

38 system to gather additional observations and insight as to possible causes for the trigger. This 

39 consultation will also help to identify whether there are multiple causes for the trigger and/or 

40 sources of contamination. Gathering information on all elements will also be useful in setting a 

41 baseline if a PWS triggers another assessment in the future. This baseline information provides a 

42 good indication of where additional follow-up may be needed. 

43

44 As with a Level 1 assessment, PWSs must document their Level 2 assessment in an 

45 assessment form, which they must complete and submit to the primacy agency within 30 days 

46 after the PWS has determined that the trigger has been exceeded. For more discussion on the 

47 assessment forms, see Chapter 3.4 of this document. 

48
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1 The Level 2 assessment should also be conducted thoroughly to capture the possibility 

2 that there may be multiple causes for the coliform positive. Level 2 assessments should be 

3 conducted as quickly as possible after notification of E. coli positive sample results. Assessors 

4 should complete the entire assessment form, even if they believe they understand the apparent 

5 cause, to ensure they have a holistic picture of the overall integrity of the system and do not 

6 inadvertently overlook a potential defect. 

7

8 3.4 Assessment Forms 

9

10 As stated previously, PWSs must complete an assessment form (either for a Level 1 or 

11 Level 2 assessment) to document their assessment process and submit it to the primacy agency 

12 for review. Appendix A of this document contains an example of a Level 1 and a Level 2 

13 assessment form. These forms are intended as conceptual examples to describe practical 

14 expectations for the level of resources committed to undertaking either a Level 1 or a Level 2 

15 assessment. Assessments conducted under the proposed RTCR should reflect the substance and 

16 effect of the elements of these example assessment checklists. However, primacy agencies may 

17 develop their own forms. Systems should contact their primacy agency to check whether to use 

18 the example forms presented in this document or a State- or system-specific form. 

19

20 The assessment forms for both Level 1 and Level 2 assessments in Appendix A are 

21 designed to cover the typical elements found within a PWS. For each element, the assessment 

22 forms provide suggestions on items to evaluate that are related to the pathways and mechanisms 

23 for microbial contamination as outlined in Chapter 1.4. Since an assessment is an examination 

24 of a particular PWS, it will therefore have different components for each system depending on 

25 the system’s source water, configuration, and the number and type of distribution system 

26 facilities present. The forms in Appendix A cannot cover all possible situations or distribution 

27 system configurations. Assessors should use professional judgment in the application of the 

28 forms to their system and provide additional information to support conclusions, if warranted. 

29

30 The primacy agency makes the final determination on the adequacy and completeness of 

31 information provided in the assessment. PWSs should be familiar with the forms and required 

32 submittals so that they are prepared for an assessment in advance, should one be required. For 

33 example, PWSs may wish to create a standard operating procedure (SOP) for what to do when 

34 coliform results trigger a Level 1 or Level 2 assessment. When developing the SOP, systems 

35 should verify with their primacy agency whether there is a specific version of the assessment 

36 form that needs to be used, and understand which data source(s) they can use to fill out the 

37 various sections. 

38

39 In the completed assessment form, the PWS must identify the results of all elements of 

40 the assessment, any sanitary defects detected, corrective actions completed, and a timetable for 

41 any corrective actions not already completed. If no sanitary defects are found in an assessment, 

42 the assessor may note that no sanitary defects were identified. Upon completion and submission 

43 of the assessment form by the PWS, the primacy agency determines if the PWS has identified a 

44 likely cause for the Level 1 or Level 2 trigger and establishes whether the system has corrected 

45 the problem. 

46

47 Appendix B provides examples of completed assessment forms. The major elements 

48 covered in the forms are discussed in Chapter 3.6 of this document. 

49
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1 3.5 Timeline for Assessments and Corrective Actions 

2

3 A PWS must complete a Level 1 or Level 2 assessment as soon as practical after the 

4 determination that a trigger has been exceeded. The completed assessment form must then be 

5 submitted to the primacy agency for review within 30 days after the PWS has determined that a 

6 trigger has been exceeded. The 30-day timeframe allows for sufficient time for problem 

7 identification and potential remediation of the problem in conjunction with the follow-up 

8 assessment, in most cases. If the primacy agency determines that the assessment is insufficient 

9 (e.g., the conditions at the well were not fully assessed, or the storage tank was not fully 

10 inspected), the primacy agency must consult with the system. If necessary after consultation, the 

11 system must submit a revised assessment form to the primacy agency on an agreed-upon 

12 schedule not to exceed 30 days from the date of the consultation. For corrections not completed 

13 by the time of submission of the assessment form (e.g., in the case where parts need to be 

14 ordered and may take longer than 30 days to be delivered and installed), the system must 

15 complete the corrective action(s) in compliance with a schedule determined by the primacy 

16 agency in consultation with the system. The system must notify the primacy agency when each 

17 scheduled corrective action is completed. 

18

19 3.6 Assessment Elements 

20

21 The minimum elements of both Level 1 and 2 assessments should include a review and 

22 identification of five key elements as outlined in the introduction to Chapter 3. Table 3.2 

23 demonstrates how the questions on the example Level 1 and Level 2 assessment forms in 

24 Appendix A correspond to the five minimum elements required by the proposed RTCR. 

25

26 Table 3.2 Summary of Assessment Form Questions by Element 

Element 

Questions on the 

Assessment Forms that 

Address the Element 

Inadequacies in sample sites, sampling protocol, and sample 

processing 3, 4 

Atypical events that may have affected distributed water quality or 

indicate that distributed water quality was impaired 1, 2 

Changes in distribution system maintenance and operation that may 

have affected or are affecting distributed water quality including water 

storage 

5, 6 

An evaluation of source water quality and treatment changes or 

conditions that may affect distributed water quality, where appropriate 7, 8, 9, 10 

Existing water quality monitoring data 1, 2 

27

28 The following sections discuss the types of activities that a PWS may perform in 

29 completing a Level 1 or Level 2 assessment. 

30

31 3.6.1 Operational Data Review (Questions 1 and 2) 

32
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1 The operational data review includes collection, compilation, and analysis of system data 

2 from a variety of sources to get a more complete understanding of system conditions and events 

3 that may have occurred prior to triggering an assessment. The data collected should include 

4 recent data as well as historical trends to provide a basis for comparison to determine if atypical 

5 events have occurred. 

6

7 The operational data elements should be reviewed by all systems, regardless of size or 

8 type. The available data and accessibility of electronic data may vary by system size and type. 

9 Large systems may have electronic databases from which to extract pertinent information 

10 including: 

11

12 • Distribution system and treatment plant process data from supervisory control and 

13 data acquisition (SCADA) systems for pumping, storage and pressure data 

14 • Water quality measurements from laboratory information management systems 

15 (LIMS) or external laboratory reporting systems 

16 • Customer complaint and water usage data from customer service information systems 

17 (CSIS) 

18 • Data on operations and repairs in the distribution system from maintenance 

19 management information systems (MMIS) 

20 • Recent and historical information from main break databases 

21 • Pipe material and condition information from asset management databases 

22 • Hydrant testing and fire fighting from fire department information 

23 • Activities performed from operations logs. 

24

25 For smaller systems, much of the data sources listed above may not be electronic and will 

26 therefore require additional effort on the system to put together and compile the data as part of 

27 the assessment. EPA therefore encourages these systems to maintain records of the above 

28 mentioned data elements to help them conduct an assessment should they be triggered to do one. 

29

30 The operational data review will provide an indication of the elements of the assessment 

31 on which to focus efforts. For example, if the SCADA data indicates some low pressure 

32 readings in a particular area of the distribution system, follow-up investigations should focus on 

33 that area. However, other areas of the distribution system should not be ignored as microbial 

34 contamination can be a result of multiple causes. 

35

36 A Level 1 assessment should include the collection and review of available data. 

37 Examples of these data include water quality (e.g., pH, turbidity, etc.) and pressure monitoring 

38 data. Tables and graphs summarizing the data and findings could be helpful supplemental items 

39 to prepare and submit to the primacy agency, if asked to do so. A Level 2 assessment may 

40 include collection of additional data that is not readily available, a deeper examination of 

41 correlations between different data sources, hydraulic analysis, and additional sampling, 

42 interviews of employees, interviews of customers in the affected areas, inspection of backflow 

43 prevention devices in suspect facilities, and more thorough inspection of facilities and sources. 

44 For example, in the case where the presence of biofilms is the suspected cause of the positive 

45 coliform samples, more sophisticated genotypic characterization techniques can be used to verify 

46 if a persistent biofilm microflora is indeed the cause of the contamination. The Level 2 

47 assessment form (Appendix A) includes a series of questions about operational activities and 

48 results of data review to provide a basis for the detailed analysis. 
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1

2 Although the PWS is not required to submit the collected data and supplemental analysis 

3 with the assessment form, EPA recommends that these items be kept on file for future reference 

4 in case the PWS gets triggered to have an assessment again. States may also want to look at 

5 these data and analysis during their review of the assessment forms or during a sanitary survey. 

6

7 Water Quality Data 

8

9 As part of any assessment, water quality data should be compiled. This data would 

10 include parameters collected in the distribution system and at the source or treatment plant. The 

11 parameters to be evaluated will vary by system type, treatment process used and other 

12 operational practices but may include the items outlined in Table 3.3. If systems do not currently 

13 collect water quality data at one of the locations suggested in Table 3.3, they should consider 

14 doing so in order to create a baseline for comparison should another assessment be triggered in 

15 the future. 

16

17 Table 3.3 Summary of Typical Water Quality Data to be Evaluated During an 

18 Assessment 

Water Quality Parameter Location of Sample Collection 

Disinfectant residual concentration 

Throughout the distribution system 

At storage tanks throughout the distribution 

system 

At the entrance to the distribution system at 

each source 

Total coliforms and E. coli

All distribution system sampling sites, 

including those for repeat and additional 

samples 

Entrance to the distribution system at each 

source 

Heterotrophic plate count All distribution system sampling sites for total 

coliforms 

Nitrite and nitrate (systems using chloramine) Distribution system sites with low disinfectant 

residual 

Treatment process performance parameters 

(e.g. turbidity, pH) 

Throughout the treatment process 

Entrance to the distribution system at each 

source 

19

20 Once the water quality data have been collected, they should be analyzed to determine if 

21 any atypical events have occurred. Depending on the data that are available, there may be 

22 several ways to examine the data. One good method is to develop a historical trend for 

23 monitoring results and individual parameters at each sampling location. Spreadsheet and 

24 graphing software can be helpful in developing and reviewing historic trends. The historical 

25 time series can be evaluated visually to determine if there are differences between current results 

26 (under assessment) and historical trends. Figure 3.1 provides an example of a historical time 

27 series graph of total chlorine measurements from distribution system samples using Microsoft 

28 Excel software. The average total chlorine concentration for each month is plotted for multiple 

29 years. This type of graph can help to identify if measured values are within normal ranges or 
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1 might represent an atypical condition within the distribution system. Similar graphs could be 

2 constructed for minimum and maximum residual disinfectant measurements, total coliform 

3 positive samples, and related water quality sampling data. 

4 Figure 3.1: Example Time Series Graph for Distribution System Chlorine Results 

5

6 Additional samples could also be collected to further understand the contamination event. 

7 These samples could include follow-up total coliform samples as well as disinfectant residual 

8 measurements. 

9

10 Supplemental data sources beyond water quality measurements could also be considered 

11 in the assessment. For example, customer complaints might show an increase in a particular area 

12 of the distribution system that could be correlated to distribution system problems. Spatial 

13 analysis and mapping of complaints using geographic information system (GIS) software can be 

14 helpful in interpreting the data, as illustrated in Figure 3.2. In this example, majority of the 

15 complaints regarding the water’s color, taste, and odor is occurring in areas where the 

16 disinfectant residual is 1.16 mg/L or less. 
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1

2 Figure 3.2: Example of Spatial Analysis of Disinfectant Residual and Customer Complaint 

3 Data 

4
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1 Public health officials also track reported illnesses, doctor visits, and purchase of over2 the-counter medicines. These public health data sources might be helpful in understanding the 

3 potential source and extent of contamination. Water systems should work to develop 

4 relationships with their local public health officials so that if an assessment needs to be 

5 conducted, health information can be more readily accessible. 

6

7 Operational Activities and Unusual Events 

8

9 Along with water quality measurements, it is important to understand the extent of 

10 activities occurring in the water system that may have resulted in total coliform-positive samples. 

11 Compilation of operational activity data may require consultation with different departments 

12 within a water utility and with external agencies. The types of activities and events to be noted 

13 would include those that might result in distribution system contamination, including: 

14

15 • Main breaks and associated repairs 

16 • Events resulting in a loss of pressure (e.g., power failures) 

17 • Flushing and hydrant testing 

18 • Construction activity that impacts water mains 

19 • Unusually high (or low) demands that might alter typical flow patterns, including 

20 temporary connections for construction and fire fighting 

21 • Break-ins and vandalism at system facilities 

22 • Treatment process upsets 

23 • Weather events 

24 • Source water changes 

25

26 Once a list of distribution system activities and events has been compiled, this list can be 

27 compared to historical records to determine if any activities or events could have led to the 

28 distribution system contamination. Further investigation of any suspect operational activities or 

29 events should be conducted. 

30

31 Consideration of flow pathways or use of a hydraulic model can also be useful in 

32 determining if a specific activity could be related to the coliform-positive samples at a given 

33 location. Figure 3.3 illustrates the output from a hydraulic modeling analysis showing the areas 

34 of influence for different pump stations in the system. Locations in this figure are color-coded to 

35 show the results of a source tracing analysis, which tracks parcels of water from a selected 

36 location. Some locations receive water from more than one source as noted in the figure legend. 

37 This type of analysis can be useful in finding the source of contamination, particularly if several 

38 positive samples fall within the influence zone of a specific distribution system pump station or 

39 tank. In this instance, systems can focus their attention on specific locations at the distribution 

40 system in determining the cause of the positive samples. However, as mentioned previously, 

41 other areas of the distribution system should not be ignored completely as the contamination can 

42 be a result of multiple causes. 

43
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1

2 Figure 3.3: Example of hydraulic modeling analysis to determine influence zones for pump 

3 stations 

4

5 3.6.2 Sample Site and Protocol Evaluation (Questions 3 and 4) 

6

7 This section of the assessment is designed to determine whether water samples could 

8 have been contaminated during the sample collection or processing, resulting in total coliform9 or E. coli-positive samples. In that case, the positive results may not indicate a distribution 

10 system problem but rather a sampling problem. Several references are available to provide 

11 detailed guidance on sampling (AWWA 2008; APHA et al. 2005; USEPA 2001; USEPA 2006d; 

12 USEPA 2006e). EPA intends to review and revise existing guidance and develop additional 

13 guidance on monitoring and sampling specific to the RTCR as needed. 

14

15 The evaluation of the sample site(s) with the positive sample(s) and the sampling 

16 protocol would be performed in a similar manner for systems of all sizes and types. Because the 

17 sample site(s) is/are a key indicator of whether the problem is system-wide or localized, the 

18 assessment would be similar for both a Level 1 and Level 2 assessment, and would include a 

19 field visit to inspect the sample location(s) or a detailed discussion with the sample collector to 

20 determine the conditions at the sample site(s). 

21

22 Some of the common items to evaluate at the sample site(s) include: 
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1

2 • Cleanliness and suitability of the sample tap and sink 

3 • Potential for hot water to enter the sample through the tap 

4 • Conditions that may have changed at the sample site since the last sample collection 

5

6 In addition to sample tap contamination, it is possible that elements of the sampling 

7 protocol that were not followed closely could result in contamination of the sample. Elements of 

8 the sampling protocol may include: 

9

10 • Removal of the tap aerator 

11 • Adequate flushing of the tap prior to sample collection 

12 • Proper storage and preparation of the sampling container 

13 • Correct storage, preservation, and handling of sample(s) during transport to 

14 laboratory 

15 • Compliance with holding time and temperature requirements 

16

17 Finally, this evaluation should include a discussion with the laboratory, either in-house or 

18 external, to determine if all laboratory quality checks were performed with satisfactory results. 

19

20 3.6.3 Water System Component Evaluations (Questions 5 to 10) 

21

22 This section of the assessment addresses the different components of a water system (e.g., 

23 the distribution system, storage facilities, etc.) to evaluate the potential for contamination at those 

24 areas. The extent to which a PWS should evaluate different components depends on the system 

25 configuration and type. Smaller systems would be expected to have fewer components and 

26 therefore a lesser level of effort in completing the water system component evaluations. Larger 

27 systems may focus their evaluation on areas of the system which have been shown to be more 

28 greatly affected, particularly if their data review confirms the extent of spread of the 

29 contamination. 

30

31 A Level 1 assessment for water system components could primarily focus on available 

32 data that indicates the condition of the component at its last inspection date, observations from 

33 recent visits by operations staff, and other related data such as disinfectant residual that might 

34 assist in focusing the assessment efforts. This would include any previously noted sanitary 

35 defects or significant deficiencies, and records on how these were addressed. An on-site 

36 inspection of components could be considered if it has been a year or more since the last 

37 inspection or sanitary survey. 

38

39 A Level 2 assessment would require a detailed investigation of the components, 

40 particularly those near a cluster of positive sample locations. This detailed investigation would 

41 require site visits and possibly hiring expert assistance for inspections, particularly for storage 

42 tanks that might require specialty equipment and confined space entry safety measures. The 

43 Level 2 assessment form (Appendix A) provides a list of questions that should be answered as 

44 part of a Level 2 assessment. The questions in the form also provide an indication of the level of 

45 detail that should be included for each component evaluation. 

46

47 For both a Level 1 and Level 2 assessment, the collection of additional samples for total 

48 coliforms with potential subsequent E. coli analysis and supporting water quality parameters is 
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1 encouraged. Systems should keep records of any special purpose samples taken in order to 

2 create a baseline for comparison should another assessment be triggered in the future. 

3

4 Distribution System Components Evaluation 

5

6 From the operational data review, the PWS should have compiled data to indicate what 

7 activities had been occurring in the distribution system, including operational changes, 

8 maintenance, and atypical events. Under the distribution system evaluation step of the 

9 assessment, further detail should be obtained for any event that might be significant and 

10 additional data could be collected. The objective of this evaluation is to determine if a particular 

11 distribution system component has a sanitary defect that would require correction, or if 

12 distribution system events could have contributed to the positive coliform samples. 

13

14 The initial focus of the distribution system evaluation should be in the area closest to the 

15 positive coliform samples. Operator knowledge or the results of a flow path analysis or 

16 hydraulic model can be used to determine the area(s) likely to be associated with a given sample 

17 site (see Figure 3.3). Once the immediate area has been examined, the evaluation can continue 

18 to areas of the distribution system farther from the positive coliform samples. 

19

20 Distribution system facilities should be evaluated to determine that equipment is 

21 operational and in good repair. The evaluation should include elements such as the ones 

22 presented in Table 3.4. Depending on system configuration, not all elements would be present in 

23 all systems. 

24

25 Appendix B includes an example of an assessment where distribution system problems 

26 were found. The assessment of the distribution system revealed an air release valve submerged 

27 in a flooded valve vault. To correct the problem, a permanent sump pump was installed and 

28 portions of the system were shock chlorinated. 

29
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1 Table 3.4 Summary of Items to Evaluate by Distribution System Component 

Component Typical Items to Evaluate 

Pump stations 

Proper operation of pumps and valves 

Recent losses of power 

Recent losses of pressure 

Proper operation of surge control appurtenances 

Distribution system pressure Maintenance of adequate pressure 

Air-relief / Air-vacuum valves Proper operation of valves 

Valve vault free of standing water and debris 

Fire hydrants Proper operation of shut-off valves 

Leaks at connection to lateral piping 

Flushing assemblies / Blow-offs Proper operation of valves 

Leaks at connection to piping 

Pipes 

Recent main breaks 

Recent leaks 

Recent installation of new mains or construction activity 

Distribution system isolation 

valves Recent operation resulting in breakage 

2

3

4

5 Storage Facilities 

6

7 Storage facilities, or tanks, have been linked to microbial contamination events and 

8 therefore are an important component to assess when responding to positive coliform samples 

9 (Clark et al. 1996). Microbial contamination can enter storage facilities either through system 

10 water or external tank breaches. If contamination is introduced through system water (i.e., 

11 transported to the storage facility from a different contamination site), microbes can remain 

12 viable and possibly multiply within the tank water and sediments. Table 3.5 outlines some 

13 typical items to evaluate for storage facilities. If warranted, a PWS should examine historical 

14 disinfectant residual data and collect additional samples. 

15
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1 Table 3.5 Summary of Items to Evaluate at Storage Facilities 

Storage Tank Element Typical Items to Evaluate 

Access hatches 

Signs of vandalism or forced entry 

Ability of hatch to seal tightly when closed 

Rust, holes, or other breaches 

Vents 

Signs of vandalism or forced entry 

Holes or other breaches in screens 

Rust, holes or other breaches in vent piping and 

penetration through tank wall 

Overflow piping Rust, holes or other breaches in piping and 

penetration through tank wall 

Control valves Correct operation of level control valves, altitude 

valves, and related appurtenances 

Tank exterior 

Signs of deterioration, rust, or other breaches 

Locations where ladders, railing, cell tower supports 

and other attachments are made 

Tank interior 

Integrity of lining material 

Presence and extent of sediment within tank; 

existence of microbes within sediment 

Presence of dead animals 

Disinfectant residual Level of disinfectant in tank, ideally at different 

tank levels 

2

3

4 Treatment Processes 

5

6 For a PWS operating a treatment plant, including those where a chlorinator at a well is 

7 the treatmentan assessment of the proper operation of the treatment process is important to 

8 determine if a plant upset could be the source of the microbial contamination resulting in positive 

9 coliform samples. For most treatment facilities, regulatory data collected for compliance with 

10 related treatment requirements (e.g., Surface Water Treatment Rule, Ground Water Rule) should 

11 be available. A review of this data may indicate a potential treatment plant problem that could 

12 have allowed microbial contaminants to enter the distribution system. When reviewing the 

13 treatment data, particular attention should be paid to disinfection processes and turbidity 

14 removal, as these processes are responsible for the majority of microbial inactivation (Letterman 

15 et al. 1999). For disinfection processes, the disinfectant feed systems and resulting disinfectant 

16 concentration should be evaluated to ensure that proper dosing has taken place and desired 

17 residuals are maintained. For turbidity removal, coagulation/sedimentation and filtration 

18 processes should be evaluated to ensure that microbial contaminants could not have entered the 

19 distribution system along with a spike in turbidity. Power outages and other events that disrupt 

20 normal operations should also be considered. 

21

22 Appendix B includes an example of an assessment where a treatment system was 

23 determined to be the cause of positive coliform samples. In this case, pressure was lost during 

24 regular maintenance of a treatment system and the system may not have been properly 

25 disinfected prior to resuming service. 

26
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1 Table 3.6 Summary of Treatment Elements to Evaluate 

Treatment Element Typical Items to Evaluate 

Equipment 

(pumps, mixing units, settling 

units, pipes, valves, chemical feed 

units, filters) 

Equipment operational and maintained in 

accordance with the treatment plant Operation and 

Maintenance procedures 

Recent installations or repairs 

Treatment Process 

 

 

New sources 

Recent changes in the treatment process 

Interruptions in treatment – lapses in chemical feed 

or proper mixing 

Turbidity measurements at all appropriate locations 

in the treatment process (source, settled water, preand post-filtration, finished water, etc.) 

Disinfectant residual measurements and C x T 

calculations 

Flow rates at each plant process 

2

3

4 Wells 

5

6 For systems served by wells, the assessment should verify the integrity of the well and 

7 proper operation of the well system to ensure that contamination could not have entered the 

8 distribution system from the wells. Particular attention should be paid to potential pathways that 

9 would allow the entrance of surface water, soil, animals, or other foreign matter into the well. 

10 The well should also be constructed to prevent the accumulation of surface water around the well 

11 head and prevent inundation during periods of flooding or increased runoff. Table 3.6 outlines 

12 some typical items to evaluate for wells. Some elements may not be present depending on the 

13 design/configuration of the well and the type of pump in the well. 

14
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1 Table 3.7 Summary of Items to Evaluate at Wells 

Well Element Typical Items to Evaluate 

Well house / enclosure Signs of vandalism or forced entry 

Well cap / Well seal Tightness of well cap or seal, presence of gaps or openings 

Well vent Vent properly screened, self-draining, and has sufficient height 

above ground 

Well casing Holes, breaks, corrosion or deformation in casing and welds 

Annular grout seal Missing, sunken, bridged, or channeled grout surrounding the well 

casing 

Pump and pump assembly Attached to casing with no unprotected openings and has watertight 

seal 

Pitless adaptor Integrity of pitless adaptor connection 

Inundation Signs of inundation by floodwater or runoff; depressions around 

wellhead 

2

3 Appendix B provides an example of an assessment where well contamination was the 

4 likely cause of positive coliform samples. The well was found to have unsanitary conditions, 

5 possibly due to recent flooding, and a corroded casing. 

6

7 Springs 

8

9 For systems served by springs, the assessment should verify the sanitary condition and 

10 proper operation of the spring and associated piping. The PWS should evaluate the condition of 

11 the spring development, impacts from surface water runoff and weather conditions, and the 

12 physical condition of the spring box. Impacts from vandalism or forced entry should also be 

13 evaluated to determine if holes or other breaches could have occurred that would allow for the 

14 introduction of microbial contaminants. Signs of inundation should be checked, including 

15 deposits of soil or soil erosion. 

16

17 Appendix B includes an example of an assessment where a spring source was 

18 contaminated through a broken pipe. The pipe was replaced to correct the defect. 

19

20 Surface Water Sources 

21

22 Surface water sources can be impacted by climatic events which can influence the 

23 influent water quality to a given treatment process. Atypical events may impede the ability of 

24 the treatment process to perform as desired and may allow for the introduction of microbial 

25 contaminants into the distribution system. Heavy rainfall and rapid snowmelt can carry large 

26 soil loads into surface water sources, thereby increasing turbidity and baseline microbial 

27 contaminant concentrations. Similarly, flooding can alter the raw water quality and require 

28 treatment changes to achieve good finished water quality. 

29

30 For systems with several surface water sources, a change from one source to another 

31 could trigger a treatment upset that might result in microbial contamination entering the 

32 distribution system. 

33

34 3.7 Qualifications of Assessors 

35
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1 3.7.1 Level 1 Assessors 

2

3 A Level 1 assessment is a PWS self-assessment that should be conducted or managed by 

4 a responsible party of the PWS. This should be someone familiar enough with the system to 

5 answer the questions in the Level 1 assessment form or to gather correct information from others 

6 who work for the system. 

7

8 3.7.2 Level 2 Assessors 

9

10 Ideally, a well-performed Level 1 assessment will prevent most systems developing 

11 conditions that will trigger them to conduct a Level 2 assessment. However when it does occur, 

12 a Level 2 assessment is triggered by a more significant event; therefore a more comprehensive 

13 assessment is needed. The level of effort and resources committed to undertaking a Level 2 

14 assessment, relative to a Level 1 assessment, will be commensurate with the more 

15 comprehensive investigation and review of available information, and the engagement of 

16 additional parties and expertise. A Level 2 assessment will likely include field investigations, 

17 sampling and additional inspections of facilities beyond those performed in a Level 1 

18 assessment. 

19

20 Level 2 assessments must be conducted by a party approved by the State. Examples of 

21 such parties may include: 

22

23 • State or primacy agency personnel 

24 • An operator certified by the State to operate a system of similar size, type, and 

25 complexity 

26 • Circuit rider 

27 • A utility supervisor or manager supported by various utility experts 

28 • A consultant/consulting engineer 

29

30 For small non-community water systems: 

31

32 • Licensed plumber 

33 • Licensed well driller 

34

35 The State will determine its criteria and process for approval of Level 2 assessors and 

36 will determine which of the above parties are appropriate to conduct the assessment given the 

37 complexity of the system and the policies of the State. If the PWS or a third party conducts the 

38 Level 2 assessment, the PWS or third party must follow the State requirements for conducting 

39 the Level 2 assessment. Systems should be aware of who may be appropriate assessors for their 

40 PWS so that if the Level 2 assessment is ever triggered, the PWS does not lose time in 

41 identifying who will conduct this assessment. When a Level 2 assessment is triggered, the PWS 

42 should resolve uncertainties about the assessor by consulting with the State as soon as possible. 

43

44 Qualities of a Level 2 assessor may include: 

45

46 • An understanding of the objectives and structure of the RTCR 

47 • An understanding of the nature of the coliform group and E. coli, including its 

48 sources, control, and public health significance 
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1 • A familiarity with bacteriological sampling practices 

2 • A working knowledge in how to interpret distribution system water quality data 

3 • A working knowledge in how to interpret distribution system water operational data 

4 • A working knowledge in how to interpret source of supply data 

5 • An understanding of disinfection practices, and the potential implications of changes 

6 in disinfection practices 

7 • Familiarity with the system 

8

9 In general, the assessor needs “working knowledge” to oversee all elements covered by 

10 the Level 2 assessment. The depth of the understanding and knowledge required will depend on 

11 the complexity of the system being assessed. For example, a small system with only a well, 

12 storage tank and limited distribution system will require a different level of expertise than a large 

13 metropolitan water system. While both have operational data, in one case the assessor may be 

14 interpreting information manually recorded from a pressure gauge while in the other case the 

15 assessor may need a working familiarity with SCADA. 

16

17 It is important to recognize that in some cases, one individual may not have all the 

18 expertise and a team approach may be needed. It is also worth noting that utilities may gain 

19 value from having someone outside their system provide a “fresh set of eyes”. The State may 

20 wish to consider allowing certified operators with the appropriate qualifications to conduct Level 

21 2 assessments at other systems. 

22

23 3.8 Assessments and Sanitary Surveys 

24

25 The performance of sanitary surveys and assessments (when triggered to do so) are 

26 important tools in protecting the quality of drinking water. Sanitary survey requirements for 

27 surface and ground water systems have been established for all system sizes and types under the 

28 Interim Enhanced Surface Water Treatment Rule (IESWTR) (USEPA 1998a) (40 CFR 

29 142.16(b)(3)), and the Ground Water Rule (GWR) (USEPA 2006b) (40 CFR 142.16(o)(2)(i)). 

30 Hence, the proposed RTCR does not include new performance requirements for sanitary surveys 

31 (e.g., how and when to conduct sanitary surveys). However, the results of a sanitary survey can 

32 impact a system’s monitoring frequency under the proposed RTCR (see additional discussion in 

33 “What are the overlaps between sanitary surveys and a Level 1 or Level 2 assessment?” in this 

34 section). 

35

36 This section is not intended to represent guidance on the performance or requirements of 

37 conducting sanitary surveys. Other resources are available for that purpose. Sanitary survey 

38 resources, such as a prep course, learner’s guide, and inspector’s field guide can be found on line 

39 at http://www.epa.gov/safewater/dwa/sanitarysurvey/. This section discusses basic differences 

40 between sanitary surveys and Level 1 and Level 2 assessments. Specifically, this section 

41 addresses what a sanitary survey is, how often it is performed, the objective of a sanitary survey, 

42 and who does them relative to Level 1 and Level 2 assessments. 

43

44 What is a sanitary survey? 

45

46 A sanitary survey is a comprehensive on-site evaluation of all water system components 

47 and operations and maintenance procedures. Specifically, a sanitary survey is defined in 40 CFR 

48 141.2 as an “onsite review of the water source (identifying sources of contamination using 
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1 results of source water assessments where available), facilities, equipment, operation, 

2 maintenance, and monitoring compliance of a public water system to evaluate the adequacy of 

3 the system, its sources and operations and the distribution of safe drinking water.” The 

4 requirements specify eight elements that must be included in a sanitary survey: (1) source; (2) 

5 treatment; (3) distribution system; (4) finished water storage; (5) pumps, pump facilities, and 

6 controls; (6) monitoring and reporting and data verification; (7) system management and 

7 operation; and (8) operator compliance with State requirements. The performance of 

8 comprehensive and periodic sanitary surveys is important in the identification and correction of 

9 significant deficiencies to ensure the long-term safety of drinking water supplies. Sanitary 

10 surveys are important tools for identifying potential vulnerabilities to fecal contamination. 

11

12 What are the differences between a sanitary survey and a Level 1 or Level 2 assessment? 

13

14 Scope

15

16 A sanitary survey is much broader in scope than either a Level 1 or Level 2 assessment. 

17 Although a sanitary survey includes elements that are similar as in an assessment (e.g., 

18 evaluation of the source water, the distribution system, storage facilities, etc.), it covers other 

19 elements such as system management and operation, and operator compliance with State 

20 requirements that are beyond what an assessment requires. The Level 1 and Level 2 assessments 

21 are specific to only those elements related to sanitary defects that provide pathways of entry for 

22 microbial contamination or those that are indicative of a failure or imminent failure in a barrier 

23 that is already in place. More information regarding the specific elements of Level 1 and Level 2 

24 assessments can be found in Chapter 3.5 of this document. 

25

26 Frequency

27

28 Sanitary surveys are performed periodically and routinely on a schedule. The State must 

29 complete sanitary surveys for all surface water systems (including ground water under the direct 

30 influence of surface water) no less frequently than every three years for community water 

31 systems and no less frequently than every five years for non-community systems. Ground water 

32 community water systems must have sanitary surveys no less than every three years, with the 

33 possibility of having the frequency reduced to no less than every five years if the system has an 

34 outstanding performance. Non-community ground water systems (both non-transient and 

35 transient non-community) are required to have sanitary surveys no less than every five years. 

36 Level 1 and Level 2 assessments on the other hand are performed in response to treatment 

37 techniques triggers so they are not on a routine schedule. Specific triggers for Level 1 and Level 

38 2 assessments are found in Chapters 3.2 and 3.3 of this document, respectively. 

39

40 Who conducts them?

41

42 Sanitary surveys must be conducted by the State or an agent approved by the State or 

43 primacy agency. A Level 1 assessment as indicated in Chapter 3.2 is a self-assessment 

44 completed by the qualified PWS staff and reviewed by the State or primacy agency. A Level 2 

45 assessment is conducted by a party approved by the State. It could be conducted by the State or 

46 primacy agency, an approved third party, or qualified PWS staff or management who meet the 

47 certifications or qualifications specified by the State or primacy agency. Chapter 3.7 of this 

48 document discusses specific qualifications of assessors. 

49
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1 What are the overlaps between sanitary surveys and a Level 1 or Level 2 assessment? 

2 Sanitary survey outcomes can impact monitoring requirements under the proposed 

3 RTCR. For example, the proposed RTCR allows all systems to transition to the new rule at their 

4 current TCR monitoring frequency, including systems on reduced monitoring under the current 

5 TCR, provided they meet certain criteria. For systems serving 1,000 or fewer people, monitoring 

6 frequency will be evaluated during each sanitary survey conducted after the compliance effective 

7 date of the RTCR. The proposed RTCR does not change existing sanitary survey requirements 

8 under the IESWTR and the GWR except to add the special monitoring evaluation that States 

9 must conduct at systems serving 1,000 or fewer people. The purpose of these special monitoring 

10 evaluations is to ensure that the distribution system is evaluated in sufficient detail. These 

11 special monitoring evaluations are not anticipated to significantly increase the burden of 

12 conducting sanitary surveys because the systems (serving 1,000 or fewer people) are relatively 

13 simple, and the evaluation is performed during the routinely scheduled sanitary survey. 

14

15 For years in which the State performs a sanitary survey of a NCWS (at least every five 

16 years for NCWSs), a sanitary survey performed during the same year can also be used to satisfy 

17 the annual site visit requirement for systems wanting to qualify for annual monitoring. Also, in 

18 some instances, the performance of an assessment (especially a Level 2 assessment) may overlap 

19 with a scheduled sanitary survey. To the extent that the requirements to perform an assessment 

20 may be satisfied as part of the sanitary survey, PWSs and States may realize a cost savings 

21 compared to performing a separate assessment. It must be kept in mind though, that the 

22 assessment must be conducted within the required timeframe and not be delayed to when the 

23 sanitary survey is scheduled to be performed. Also, the person doing the assessment would have 

24 to be qualified to conduct a sanitary survey and the investigation would have to meet the 

25 minimum criteria of both the assessment as well as the sanitary survey. 

26

27 Sanitary defects that are identified during an assessment may or may not be considered to 

28 be a significant deficiency according to the guidelines set by the primacy agency. The PWS 

29 should coordinate with their primacy agency regarding whether the Level 2 assessment can be 

30 considered part of a required sanitary survey. 
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1 4. Corrective Actions 

2

3

4 This chapter discusses the corrective action requirements of the proposed RTCR and 

5 various examples of corrective actions that can help mitigate or eliminate sources of coliform 

6 contamination that may occur during operation and maintenance of a treatment process or a 

7 water system. Table 4.2 provides a summary of those corrective actions, and the purpose or type 

8 of water quality problem addressed by each action. 

9

10 As mentioned in Chapter 2, the three main objectives of the proposed RTCR are: (1) to 

11 evaluate the effectiveness of treatment, (2) to determine the integrity of the distribution system, 

12 and (3) to signal the possible presence of fecal contamination. While a number of other 

13 regulations also focus on treatment (such as the suite of Surface Water Treatment Rules or the 

14 Ground Water Rule), the proposed RTCR builds on the barriers established at the source and 

15 treatment plants and seeks to maintain a sufficient barrier in the distribution system. The 

16 corrective actions described in this chapter represent key actions for maintaining or restoring the 

17 integrity of the distribution system barrier. This multiple barrier approach is essential to 

18 protecting public health and systems may find that the corrective actions listed in this chapter 

19 may improve their compliance for a number of regulations, not just the proposed RTCR. The 

20 interrelated nature of regulations can also be a challenge as adjustments to improve compliance 

21 for one rule may inadvertently affect a system’s ability to comply with another rule. Issues such 

22 as these can be managed with careful consideration and are addressed in Chapter 4.4 of this 

23 document. 

24

25 4.1 Common Causes 

26

27 An overview of general causes of total coliforms and E. coli in the distribution system 

was presented in Chapter 1.4. Discussions and informal surveys with States and PWSs8 28 have 

29 identified the following as some of the common causes of total coliforms and E. coli detections 

30 in the distribution system, a number of which are interrelated: 

31

32 • Failure to disinfect (or improper disinfection) after maintenance work on the 

33 distribution system 

34 • Main breaks, especially in certain vulnerable locations such as under a stream or high 

35 groundwater level 

36 • Holes in storage tank, inadequate screening, etc. which could allow animals and/or 

37 fecal matter to enter the tank 

38 • Loss of system pressure (sometimes associated with main breaks or loss of power) 

39 • Lack of regular flushing programs 

40 • Biofilm build-up in the distribution system, including biofilms at multiple locations or 

41 that move throughout system, or those associated with seasonal changes and/or loss 

42 of disinfectant residual 

                                                           

8

 Informal surveys of their constituents were conducted from February to March 2010 by the American Water 

Works Association (AWWA), the Association of Metropolitan Water Agencies (AMWA), and the Association of 

State Drinking Water Agencies (ASDWA) to determine the common causes of coliform-positive results in the 

distribution system and the types of corrective actions taken in response to those positive results. 
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1 • Cross connections, especially at certain high-risk locations (e.g., hospitals, chemical 

2 plants, chemical holding/storage facilities, funeral homes, etc.) 

3 • Inadequate disinfectant residuals 

4 • Contaminated sampling taps 

5 • Sampling protocol errors. 

6

7 The specific cause(s) of total coliforms and E. coli in the distribution system will differ 

8 from system to system. The Level 1 and Level 2 assessments discussed in Chapter 3 are 

9 designed to help identify the specific causes so they can be appropriately addressed. 

10

11 4.2 Common Corrective Actions 

12

13 The type of corrective action performed will depend on the identified cause. Some 

14 actions can be performed in response to multiple types of causes, and multiple actions may be 

15 needed in response to a single identified cause. Table 4.1 describes some common general 

16 actions that would be taken in response to the common causes listed in Chapter 4.1. Each of the 

17 corrective actions listed in Table 4.1 are described in more detail in the following sections, along 

18 with examples that can help mitigate or eliminate the sources of coliform contamination. Table 

19 4.2 summarizes these actions along with the general purpose for taking such actions. 

20

21 Corrective actions should be completed in accordance with State guidance and industry 

22 best practices. States often have guidance for operation and maintenance of the water system, 

23 and for emergency response planning and implementation of cross connection control programs. 

24 Systems should be aware of State guidelines for investigation, operation and maintenance, and 

25 corrective action, and consult with the State as necessary to complete corrective actions that the 

26 State will consider to be sufficient. An example of State guidance is the Recommended 

27 Standards for Water Works (also known as the 10 States Standards) (Great Lakes et al. 2007). 

28

29 Appendix C of this document presents additional information on the common causes of 

30 coliform detection in the distribution system, possible corrective actions which systems can take 

31 to correct the problem, and additional sources of information for correcting the problem. 

32

33 Drinking water system components that are used to implement correction actions to 

34 distribution system problems should be in compliance with NSF/ANSI Standard 61. NSF/ANSI 

35 Standard 61 addresses drinking water system components that are in contact with finished 

36 drinking water and whether contaminants leach or migrate from the product/material into the 

37 drinking water at levels that are above acceptable levels in finished waters. 

38

39 In addition, Appendix D contains a listing of AWWA Standards that are typically 

40 minimum best practices and help to ensure that a product (e.g., pipes, fittings, meters, etc.) or a 

41 process (e.g., main flushing, main installation, etc.) described in a standard will provide 

42 satisfactory service. These standards can be valuable resources in implementing corrective 

43 actions. 
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1 Table 4.1: Common Causes and Associated Common Corrective Actions 

Common Cause Common Corrective Action(s) 

Failure to disinfect (or improper disinfection) 

after maintenance work in the distribution 

system 

Disinfection 

Main breaks Disinfection 

Replacement/Repair of Distribution System Components 

Holes in storage tank, inadequate screening, 

etc. 

Replacement/Repair of Distribution System Components 

Maintenance of Storage Facility 

Addition of Security Measures 

Development and Implementation of an Operations Plan 

Loss of system pressure Maintenance of Adequate Pressure 

Addition or Upgrade of On-line Monitoring and Control 

Biofilm accumulation in the distribution 

system 

Flushing 

Maintenance of Adequate Pressure 

Cross connections 

Maintenance of Adequate Pressure 

Implementation or Upgrade of a Cross Connection 

Control and Backflow Prevention Program 

Inadequate disinfectant residuals 

Disinfection 

Flushing 

Maintenance of Appropriate Hydraulic Residence Time 

Addition or Upgrade of On-line Monitoring and Control 

Contaminated sampling taps Replacement/Repair of Distribution System Components 

Sampler Training 

Sampling protocol errors Sampler Training 

Development and Implementation of an Operations Plan 

2

3
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1

2 Table 4.2 Summary of Corrective Actions 

Action Purpose 

Disinfection (Chapter 4.2.1) Improve or maintain disinfectant residual in the distribution 

system. 

Flushing (Chapter 4.2.2) 

Keep system clean and free of sediment. 

Reduce disinfectant demand of pipe surfaces. 

Remove stagnant, untreated, or contaminated water. 

Address water quality deterioration at dead-ends. 

Replacement / Repair of Distribution System 

Components (Chapter 4.2.3) 

Valves 

Water Mains 

Fittings 

Hydrants 

Meters 

Dedicated Sample Taps 

Reduce potential sources / pathways of contamination from 

improper installation or material degradation. 

Maintenance of Adequate Pressure (Chapter 4.2.4) 

Booster Pumping Stations 

Pump Modifications or Replacement 

Variable Frequency Drive 

Elevated Storage Facilities 

Surge Relief Valves 

Surge Tanks 

Minimize sudden changes in water velocity which impact 

system pressure. 

Reduce risk of backflow and intrusion contamination resulting 

from low pressures. 

Reduce risk of hydraulic disturbances to pipe surface biofilm. 

Maintenance of Appropriate Hydraulic Residence 

Time (Chapter 4.2.5) 

Looping Dead-Ends 

Installing Appropriate Main Sizes 

Automated Flushing Devices 

Storage Facility Modifications 

Mitigate water quality problems associated with increased water 

age (e.g., higher DBP formation, reduced disinfectant residual, 

increased microbial activity, nitrification, and taste-and-odor 

problems). 

Maintenance of Storage Facility (Chapter 4.2.6) 

Inspecting / Cleaning of Tanks 

Lining of Storage Tanks 

Vent / Hatch Repair 

Tank Repair 

Remove contamination from birds and insects. 

Remove accumulated sediment. 

Protect against tank wall corrosion. 

Prevent entry of vectors (e.g., birds, etc.) 

Implementation or Upgrade of a Cross Connection 

Control and Backflow Prevention Program 

(Chapter 4.2.7) 

Prevent flow of non-potable substances into the distribution 

system. 

Sampler Training (Chapter 4.2.8) 

Reinforces proper sampling and sample handling procedures to 

obtain uncontaminated samples. 

Reduces errors in sampling results. 

Addition or Upgrade of On-line Monitoring and 

Control (Chapter 4.2.9) 

Water Quality Monitoring & Control 

Pressure Monitoring & Control 

Automatically control and monitor disinfectant dosages and 

water quality parameters (other than total coliforms). 

Monitor pressure levels to identify physical problems in the 

system (e.g., pipe breaks, leaking valves, etc.). 

Addition of Security Measures (Chapter 4.2.10) 

Monitor potential locations for vandalism or security breaches 

that could lead to water contamination. 

Increase public confidence in protection of their drinking water. 

Development and Implementation of an Operations 

Plan (Chapter 4.2.11) 

Develop Standard Operating Procedures (SOPs) 

Develop a Sampling Plan 

Perform Routine Inspections 

Develop an Emergency Response Plan 

Ensure the availability of appropriately qualified 

operators 

Integrate all operations and maintenance functions to meet flow, 

pressure, and water quality goals. 

Establish a routine distribution system sampling plan. 

Implement an inspection and maintenance program to reduce 

sanitary defects. 

Define an emergency response plan for the distribution system 

to reduce reaction time and minimize confusion in emergencies. 

Ensure around-the-clock responsiveness. 
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1

2

3 4.2.1 Disinfection 

4

5 Many systems use disinfection (by applying either temporary disinfection, shock 

6 chlorination, or booster disinfection) as a response to positive coliform results. It is also 

7 commonly used as a precautionary measure, especially when the cause of a positive coliform 

8 sample has not been identified, to help mitigate any potential contamination that could be present 

9 in the system. If a system is found to have contamination that requires a long term solution, it 

10 may take time for the system to design and install a corrective action. In the meantime, the 

11 system cannot serve the contaminated water to its customers. The primacy agency may require 

12 the system, as part of its corrective action, to apply chlorination until the contamination is 

13 eliminated or a corrective action is put in place. When temporary chlorination is applied in 

14 response to a coliform occurrence, the system should notify the State Chlorination should be 

15 kept in place until the State has reviewed the situation and has determined if the contamination 

16 has been addressed and the temporary disinfection can be suspended or if the disinfection needs 

17 to be continued. 

18

19 Temporary disinfection can be conducted at the point of entry to the distribution system 

20 or can be installed at a location in the distribution system to target a specific area. Depending on 

21 the extent of the problem revealed by the Level 1 or Level 2 assessment, system-wide or targeted 

22 disinfection (such as shock chlorination) may be an appropriate corrective action. 

23

24 For non-disinfecting systems or those using free chlorine, temporary/additional 

25 disinfectant in the form of sodium hypochlorite (bleach) is often used because it is easier to 

26 install and operate than gaseous chlorination or other disinfection methods, particularly on a 

27 temporary basis. It is a low cost option that can provide some protection to a portion of a 

28 distribution system or across an entire pipe network. However, care should be used in the 

29 storage of hypochlorite as age and temperature have been shown to be associated with the 

30 conversion of hypochlorite to perchlorate (Stanford et al. 2009). 

31

32 It is important to note that temporary disinfection is better suited to deal with a single 

33 event and is not intended to deal with a chronic problem like source water contamination. 

34 Systems using chloramine as a secondary disinfectant should carefully balance chlorine addition 

35 with ammonia to maintain the desired chlorine to ammonia ratio for optimal chloramine 

36 formation. 

37

38 Booster disinfection facilities located throughout a distribution system can provide 

39 additional chemical treatment in the system. Booster disinfection can improve or maintain 

40 disinfectant residual levels in a distribution system. Prior to discharge into the distribution 

41 system, potable water from a treatment facility must have a certain disinfectant residual level to 

42 minimize microbial growth. These levels are defined by State and Federal government 

43 regulations. Organics and reduced metals in the water also consume disinfectant residuals; 

44 therefore, it is vital to maintain an appropriate disinfectant residual level in the system in order to 

45 avoid increased levels of total coliforms in the system. 

46

47 See Chapter 4.4 of this document for a discussion of simultaneous compliance issues 

48 systems should consider when using disinfection as a corrective action. 

49
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1 4.2.2 Flushing 

2

3 A water main flushing program helps to keep the system clean and free of sediment, can 

4 reduce the disinfectant demand of pipe surfaces, and removes stagnant water and untreated or 

5 contaminated water that may have entered the system (Kirmeyer and Friedman 2000). Flushing 

6 can also be used to address water quality deterioration at dead-ends. The volume of water 

7 flushed is related to the length of flushing time and flow rate from the hydrant. Water systems 

8 should flush until a disinfectant residual can be measured or some other water quality target is 

9 reached (other than just until the water appears clear). A system could perform scheduled 

10 system-wide flushing, and/or periodic unscheduled (or “spot”) flushing which can be used to 

11 address isolated water quality problems, including total coliform-positive samples. However, 

12 spot flushing should not be used as the only solution to positive coliform results or low residual 

13 events. Flushing should be used until the system identifies the source of the problem and a more 

14 permanent fix. 

15

16 Upon obtaining a positive coliform sample, a common response is to flush the area near 

17 the sample site to draw in fresh water and remove any contaminated water that may be present. 

18 This unscheduled spot flushing is different from a routine flushing program in that the flushing 

19 only occurs when triggered by a water quality measurement, customer complaint, or similar 

20 event. 

21

22 Minimum elements of a flushing scheduled/routine program are outlined in the AWWA 

23 G200 Standard (AWWA 2004) and include: (1) a preventive approach to address local problems 

24 or customer concerns and routine flushing to avoid water quality problems; (2) use of an 

25 appropriate flushing velocity to address water quality concerns; and (3) written procedures for all 

26 elements of the flushing program including water quality monitoring, regulatory requirements 

27 and specific flushing procedures. 

28

29 4.2.3 Replacement / Repair of Distribution System Components 

30

31 Distribution system components and appurtenances such as valves, pipes, fittings, 

32 hydrants, meters, and sample taps are integral parts of a water system. These components are 

33 also potential sources of contamination if improper installation or material degradation allows 

34 leaks or other entry points for contamination into a distribution system. Inspection of 

35 components may indicate that they should be replaced or repaired as part of proper maintenance, 

36 whether or not it is identified as the cause of the leak or as a possible entry point for 

37 contamination. Some components throughout the distribution system are located below grade, 

38 making a leak difficult to locate. However, a number of technologies have been developed to 

39 locate leaks below grade. Any repairs or replacements should be completed with proper 

40 attention to prevent contamination of the distribution system. See the AWWA standards listed in 

41 Chapter 4.5 of this document for more information on installation, repair, and replacement of 

42 distribution system components. 

43

44 Valves 

45

46 Valves are located throughout a distribution system to isolate portions of the system as 

47 needed. Leaks at the connection points between the valve and the adjacent pipe, as well as a 

48 valve seat or valve body, can create a pathway for contamination. 

49
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1 Water Mains 

2

3 The condition of distribution system piping can be vital to the quality of water being 

4 conveyed to a community. Contaminants may enter through holes, breaks, cracks or joints in the 

5 piping. The condition of a pipe can vary based on type, age, and location of the pipe. 

6 Depending on the condition of the pipe, the water main can be replaced or repaired to stop 

7 infiltration into the system. 

8

9 Fittings 

10

11 There are many types of fittings located throughout a distribution system. The most 

12 common type of distribution system fitting is a cross. A cross has four connections which make 

13 it more susceptible to leaks. Leaks can occur because of a crack on the fitting or through the 

14 gasket between the fitting and another appurtenance, e.g., a valve, cap, or pipe. 

15 

16 Hydrants 

17

18 Hydrants are located throughout a distribution system to provide potable water at 

19 required fire flow pressures for emergency situations. Hydrant connections are tapped off the 

20 distribution system; therefore, these connections can be possible locations for coliform 

21 contamination to enter a distribution system. Replacing a damaged or faulty fire hydrant can 

22 help eliminate sources of contamination into the distribution system as it eliminates a pathway 

23 for contamination. Systems should attempt to control usage of the hydrants as much as possible 

24 to eliminate unauthorized usa and install backflow prevention devices where possible. 

25

26 Meters 

27

28 Meters are located at entry points to commercial, residential, and industrial facilities to 

29 measure the amount of water that is consumed at a particular location. Sizes for each of the 

30 meters will vary based on the type and usage requirements of a facility. Contamination may 

31 enter through the connection points of the meter and the distribution system. Replacing a broken 

32 or faulty meter can help prevent contamination of the distribution system through leaks, as it 

33 eliminates a pathway for contamination. 

34

35 Dedicated Sample Taps 

36

37 Typical sample locations often include both customer taps and dedicated sampling 

38 stations. A dedicated sampling station is a device that is plumbed directly into a distribution 

39 system line to provide “improved access to the distribution system water and provide 

40 reproducible samples that are representative of water quality at the customer’s meter” (Kirmeyer 

41 and Friedman 2000). Installing dedicated sample taps can therefore minimize the occurrence of 

42 contamination that can result from improper sampling practices and minimize concerns about 

43 water quality in customer plumbing. 

44

45 Dedicated sampling stations should be of metal construction, have unthreaded nozzles or 

46 a design approved by the State, and be located so as to be representative of the water in the 

47 distribution system. They are typically covered to protect them from birds, insects, dirt and other 

48 sources of outside contamination. Freezing of dedicated sampling taps has occurred in northern 

49 climates and that possibility should be considered when deciding whether and how to install such 
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1 taps. Figure 4-1 is a graphic schematic detailing the components of a dedicated sampling station. 

2 Figure 4-2 is a photograph of a dedicated sampling station. 

3

4 Additional guidance on selection of an appropriate sample tap, including factors such as 

5 type of tap and sink, can be found in Narasimhan et al. 2004. 

6

7

8

9

10

11

12 Source: Water Distribution System Operation and Maintenance, A Field Study Training Program.  USEPA Office of Drinking  

13 Water and California Department of Health Services, Sanitary Engineering Branch.  Hornet Foundation Inc., Sacramento, Calif.

14 (1989, 2nd ed.).

15

16 Figure 4.1: Dedicated Sampling Station Schematic 

17
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1

2 Source: With permission courtesy of Koraleen Enterprises.

3

4 Figure 4.2: Dedicated Sampling Station 

5

6

7 4.2.4 Maintenance of Adequate Pressure 

8

9 Pressure losses can occur in the distribution system as a result of events such as flushing, 

10 main breaks, power outages, service line breaks, and fires. Pressure transients (also called 

11 pressure surges or water hammer) can occur when an abrupt change in water velocity occurs due 

12 to a sudden valve closure, pump shutdown or startup, or loss of power. The resulting pressure 

13 wave, with alternating low and high pressures, travels back and forth through the distribution 

14 system until the pressure is stabilized. Low pressure conditions in the distribution system can 

15 allow a flow reversal or backflow of non-potable water to enter the system from a cross 

16 connection or other source such as intrusion. Pressure transients can also create hydraulic 

17 disturbances that allow biofilm material on pipe surfaces to enter the bulk water. Systems should 

18 check with their State regarding distribution system pressure requirements. Industry guidelines 

19 suggest that system pressure should be maintained within the range of 35 to 100 psi at all points 

20 in the distribution system (AWWA 1996). The AWWA G200 standard indicates that the 

21 minimum residual pressure at the service connection under all operating conditions should be 

22 greater than 20 psi (AWWA 2004). Many states also have guidelines regarding distribution 

23 system operating pressure. Written standard operating procedures for pump, hydrant and valve 

24 operation under routine and emergency conditions can help minimize sudden changes in water 

25 velocity that impact system pressure. 

26 

27 Other actions that can help to maintain an adequate pressure in the distribution system 

28 include building new booster pump stations and elevated storage facilities, modifying existing 

29 high services pumps, and installing variable frequency drives, surge relief valves, and surge 

30 tanks. 

31

32 Booster Pumping Stations 

33

34 Booster pumping stations are used in the distribution systems to move water from lower 

35 pressure zones to higher pressure zones and to maintain pressure at desirable levels. As the 
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1 water system grows and changes, existing booster pump stations may no longer be able to 

2 maintain the desired pressure across the distribution system. In those cases, the construction of a 

3 new booster station may be required. The construction of a completely new booster pump 

4 station is not always required to maintain an appropriate pressure in a water system. There may 

5 be situations where a modification or replacement of an existing pump is sufficient. 

6

7 Variable Frequency Drive 

8

9 A variable frequency drive (VFD), also called a variable speed drive, allows a booster 

10 pump to supply the required amount of flow based on system demand with a pressure set point to 

11 maintain constant system discharge pressure, controlled to within a few psi of an operator–

12 adjustable system pressure set point. VFDs work with a system pressure transmitter to control 

13 the system pressure set point. 

14

15 Elevated Storage Facilities 

16

17 Elevated storage is provided within the distribution system to supply peak demand rates 

18 and equalize system pressures. In certain systems, elevated storage is more effective and 

19 economical than ground storage because by nature of its elevated location, pumping 

20 requirements may be reduced, and the storage can serve as a source of emergency supply since 

21 system pressure requirements can still be met temporarily when pumps are out of service. 

22 Elevated storage tanks are often sited in areas having the lowest system pressures during 

23 intervals of high water use. These areas are often those of greatest water demand or those 

24 farthest from pump stations. Elevated tanks are generally located at some distance from the 

25 pump station serving a distribution pressure level, but ideally are not placed outside of 

26 boundaries of the service area unless the facility can be located on a nearby hill. Elevated tanks 

27 are built on the highest available ground so as to minimize the required construction cost and the 

28 height requirements. 

29

30 Surge Relief Valves 

31

32 Surge relief valves provide pressure management by ejecting water out of a side orifice to 

33 prevent excessive high-pressure surges and can also be triggered to open on a downsurge in 

34 pressure in anticipation of an upsurge to follow. Surge relief valves must always be used with 

35 caution for they can make low-pressure conditions in a line worse than they would be without the 

36 valve. 

37

38 Surge Tanks 

39

40 The four common types of surge tanks include pneumatic or closed tanks, open 

41 standpipes (or air chambers), one-way surge tanks (allows water to flow only from the tank into 

42 the pipeline), and two-way surge tanks (allows flow to and from the tank). If water is stored in 

43 these tanks for long periods of time, the water may lose its disinfectant residual and microbial 

44 growth and other water quality problems may results. Proper operations and maintenance of 

45 surge tanks is required to prevent poor quality or contaminated water from entering the 

46 distribution system. 

47

48 Hydropneumatic tank systems are a popular way to provide pressure control and 

49 stabilization in smaller water distribution systems; however, they are not typically used in larger 
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1 systems. A hydropneumatic tank system allows for fluctuations in water distribution system 

2 pressure, and a potential cushion against water hammer. The system also minimizes booster 

3 pump on-off cycles so that a recommended frequency of 10-15 cycles per hour can be 

4 maintained. 

5

6 The pressure tank uses a compressed air head-space to maintain system pressure. As 

7 water system demand increases, water in the pressure tank discharges into the system and 

8 reduces the pressure tank’s water level, which expands the air cushion above the water and 

9 decreases the tank air pressure. When the air reaches a determined set point, the air compressor 

10 comes on to recharge the air space and cycles off when the high pressure set point is met. If the 

11 water demand continues to increase, the booster pumps will cycle on at the low water level and 

12 replenish the water level in the pressure tank. The pressure tank must be sized correctly, because 

13 its size determines the frequency of pump cycling. 

14

15 4.2.5 Maintenance of Appropriate Water Age, Hydraulic Residence Time, and Mixing 

16

17 Water quality problems associated with increased water age include reduced disinfectant 

18 residual, increased microbial activity, nitrification, and/or taste and odor problems. As water 

19 travels through the distribution system, chlorine continues to react with natural organic matter 

20 (NOM) to form disinfection by-products (DBPs). Thus, increased water age can also lead to 

21 higher DBP concentrations. Water systems should develop an overall strategy to manage the 

22 water age in their distribution systems, while considering the need to have adequate storage for 

23 emergencies. Establishing a water age goal is system-specific depending on system design and 

24 operation, water demands, and water quality (e.g., DBP formation potential). In the US, the 

25 average distribution system retention time is 1.3 days and the average maximum retention time is 

26 3.0 days based on a survey of 800 medium and large water utilities (AWWA and AwwaRF 

27 1992). Water age can be controlled through a variety of techniques including management of 

28 finished water storage facilities, looping of dead-ends, and re-routing of water by changing valve 

29 settings. Additional guidance is provided in the AwwaRF report, Managing Distribution System 

30 Retention Time to Improve Water Quality (Brandt et al. 2004). 

31

32 Looping Dead-Ends 

33

34 Dead-end pipes often result in stagnant water conditions where water age increases, 

35 which can cause water quality problems. One of the solutions to address the stagnant water issue 

36 is looping of dead-ends. However, looping should be evaluated carefully on a case-by-case basis 

37 as it may not actually reduce the long detention times present in those areas. 

38

39 Installing Appropriate Main Sizes 

40

41 Most distribution systems have been designed to meet a minimum hydraulic capacity. 

42 Additional capacity is generally included at the design stage to accommodate for future growth 

43 or to allow more flexibility in the configuration of a distribution system network. A PWS may 

44 also have a policy to limit the number of different pipe diameters within the system in order to 

45 simplify construction and maintenance. Consequently, network pipes tend to be larger than is 

46 necessary to meet the daily demand from the network leading to increased retention time. 

47 Hence, there can be an option to replace mains with smaller diameter pipes but still maintain the 

48 required hydraulic capacity. 

49
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1

2

3 Installing Automated Flushing Devices 

4

5 Automated flushing devices are used to purge accumulated sediments at low spots and 

6 dead-ends of pipelines at regular intervals, and to drain pipelines for repairs, maintenance, and 

7 inspection. These devices are best suited to rural networks in which security of the units and 

8 disposal of the water flushed is less problematic. An additional drawback of installing these 

9 devices is the volume and value of the wasted water may be unacceptable. However, in 

10 networks with long pipe runs terminating in dead-ends, there may be few viable alternatives to 

11 flushing for controlling retention time. 

12

13 Storage Facility Modifications 

14

15 Most storage facilities have been designed focusing more on quantity, cost, service life, 

16 appearance, and shape than on maintaining water quality. Water quality in storage facilities is 

17 affected by the mixing patterns that occur primarily during the filling cycle, the long term 

18 residence time, and the interaction between these two phenomena. Old water in stagnant zones 

19 can often have very high DBPs and low to no disinfectant residual. This water can be released 

20 into the system during periods of high demand. Increasing volume turnover reduces the average 

21 hydraulic residence time (HRT) in finished water storage facilities, thereby reducing DBP 

22 formation, loss of disinfectant, and microbial growth. Kirmeyer and Friedman (2000) 

23 recommend complete turnover every three to five days but suggest that water systems establish 

24 their own turnover goal based on system-specific needs and goals. Improving mixing in finished 

25 water storage facilities can help eliminate stagnant zones. Mixing can be improved by 

26 increasing inlet momentum, changing the inlet configuration, increasing the fill time, and by 

27 installing mixing devices within the storage facility. 

28

29 It may be necessary to reduce the water volume in a storage tank or increase demand on 

30 the tank to achieve increased volume turnover. Decommissioning storage facilities may be an 

31 appropriate strategy to reduce water age if existing facilities are oversized and not needed for 

32 emergency conditions, fire protection, or for maintaining system pressure. A professional 

33 engineer should review system needs, system design, and operation to determine if the existing 

34 storage capacity and tank operation are appropriate. 

35

36 Inlet/outlet configuration

37

38 Inlet and outlet configuration are critical in the development of proper mixing in a 

39 finished water storage facility. The inlet structure should be located and sized to disperse the jet 

40 into the storage facility as well as to maintain a jet sufficient for mixing. In particular, the 

41 location and orientation of the inlet pipe relative to the tank walls can have a significant impact 

42 on mixing characteristics. The physical modifications to the inlet pipe for improving mixing 

43 within the tanks include: 

44

45 • Changing the orientation of the inlet pipe and/or 

46 • Decreasing the inlet diameter to increase the jetting action. 

47

48 The outflow configuration does not significantly influence mixing, but operation of the 

49 inlet and outflow are important because flow entering the tank and leaving the tank at the same 
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1 time can negatively impact mixing and should be avoided. Furthermore, when the inlet/outlet is 

2 a common pipe, the ability to reduce the inlet diameter to achieve a higher inflow velocity and 

3 better jetting action will be constrained by the need to maintain an outflow capacity adequate to 

4 satisfy system operational and fire flow requirements. For this reason, it is recommended to 

5 eliminate common inlet/outlet pipes. 

6

7 Installation of mixing devices

8

9 Mixing the storage facility contents to reduce stagnant zones can also be accomplished by 

10 installing mixing devices. Special precautions are needed with mechanical mixing devices 

11 because of potential contamination to finished water by the mixer mechanism lubrication system. 

12 Multiple mixing devices may be needed and the PWS should consider the increased maintenance 

13 requirements inside the storage facility. 

14

15 Increasing volume turnover

16

17 As mentioned earlier in this section, increasing the volume turnover reduces the average 

18 HRT in the storage tank. Turnover can be accomplished by making operational modifications to 

19 the storage tank such as increasing the water level fluctuation or drawdown between fill and 

20 draw cycles. The water level should be lowered in one continuous operation not in small 

21 incremental drops throughout the day. 

22

23 Operational modifications may be limited by the following considerations: 

24

25 • Control of flow rates during tank filling may be needed to minimize the potential for 

26 low pressure in the distribution system; 

27 • Changes in operating protocol for booster stations and other tanks to achieve turnover 

28 while maintaining adequate pressure system-wide. 

29

30 4.2.6 Maintenance of Storage Facility 

31

32 Finished water storage tanks are an important component of a PWS’s distribution system. 

33 Tanks are usually designed for three purposes: reduce pressure fluctuations in the distribution 

34 system, equalize water demands, and provide water reserves for emergencies such as fires and 

35 power outages. 

36

37 The two main categories of water storage tanks include ground storage tanks and elevated 

38 storage tanks (see previous discussion on elevated storage tanks in Chapter 4.2.5). Ground 

39 storage tanks can be below grade, partially below grade, or at ground level in a distribution 

40 system and are usually constructed of a variety of materials, including steel, concrete, and 

41 fiberglass reinforced plastic. Elevated storage tanks are typically constructed of steel. 

42

43 Contamination from birds and insects can be a source of microbial contamination in the 

44 distribution system. Maintenance on a storage tank can significantly reduce the possibility of 

45 contamination or recontamination. Some actions include inspecting and cleaning, lining the 

46 interior of the tank, repairing vents and/or hatches, and repairing the tank itself. 

47

48 Inspection / Cleaning of Tanks 

49
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Proposed Revised Total Coliform Rule 4-14 August 2010 

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1 Tank inspections can provide useful information on the physical condition of the exterior 

2 and interior of the tank, identifying potential sources of microbial contamination. Inspections 

3 can also identify the accumulation of sediment within storage tanks due to particle settling in the 

4 tank or the dissolving of cementitious materials of a concrete tank from soft, low alkalinity, low 

5 pH waters. There are several water quality issues associated with sediment buildup in a storage 

6 tank, including increased disinfection demand, microbial growth, disinfection by-product 

7 formation, and increased turbidity. 

8

9 Lining of Storage Tanks 

10

11 Lining the interior of a water storage tank is another action that can be taken to reduce the 

12 potential for coliform contamination and recontamination of a distribution system. Corrosion 

13 and corrosion product buildup from excessive interior corrosion can also result in water quality 

14 issues such as increased disinfection demand, microbial growth, and increased turbidity. 

15

16 Vent / Hatch Repair 

17

18 One of the most common sources of contamination in a water storage tank is the 

19 improper design and maintenance of vents and roof hatches. These accessories can provide entry 

20 points for debris as well as microbial contamination from birds and insects. Aging water storage 

21 tanks with damaged tank covers can also be a source of microbial contamination. To prevent 

22 contamination and recontamination of the water supply, damaged vents, hatch roofs, and tank 

23 covers should be repaired or replaced immediately. 

24

25 Tank Repair 

26

27 Aging water storage tanks can provide entry points for debris as well as microbial 

28 contamination from birds and insects and should be replaced or repaired immediately to prevent 

29 contamination and recontamination of the water supply. 

30

31 4.2.7 Implementation or Upgrade of a Cross-connection Control and Backflow Prevention 

32 Program 

33

34 Implementing a Cross-connection Control and Backflow Prevention (CCCBFP) Program, 

35 including the installation of backflow prevention assemblies and devices, can prevent the flow of 

36 non-potable substances into the distribution system. When implementing the CCCBFP Program, 

37 the drinking water system should adhere to applicable State and/or local criteria, codes, and/or 

38 regulations. Some codes or regulations may include documenting installation procedures and the 

39 periodic testing of backflow prevention assemblies. CCCBFP can prevent the introduction of 

40 non-potable substances into the public water supply due to backsiphonage or backpressure. 

41

42 Backflow prevention equipment installation and maintenance is generally the consumer’s 

43 responsibility. However, depending on how a system implements the CCCBFP, the customer 

44 and the PWS can share costs for the equipment and equipment installation, inspection, testing, 

45 and maintenance. The PWS, on the other hand, is primarily responsible for the administration of 

46 cross-connection control and backflow prevention and the inspection, review, and approval of all 

47 backflow prevention assemblies and devices. 

48
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Proposed Revised Total Coliform Rule 4-15 August 2010 

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1 4.2.8 Sampler Training 

2

3 Implementation of a sampler training program provides guidelines for procedures that 

4 samplers must follow to collect valid, uncontaminated samples for analysis of total coliforms in 

5 the distribution system. Training sessions for operators reinforce proper sampling and sample 

6 handling procedures to obtain uncontaminated samples. 

7

8 4.2.9 Addition or Upgrade of On-line Monitoring and Control 

9

10 Currently, monitoring of total coliforms is performed through grab samples at the 

11 treatment plant and throughout the distribution system. These grab samples are then analyzed in 

12 a laboratory to determine whether total coliforms are present or not in the grab sample. To 

13 ensure sufficient treatment has been provided, grab sample results, disinfectant dosages, and 

14 certain water quality parameters, such as disinfectant residual levels, can be correlated. Since 

15 automatic monitoring is not available for total coliforms, PWSs can instead automatically control 

16 and monitor for disinfectant dosages and water quality parameters. 

17

18 Water Quality Monitoring and Control

19

20 The ability of a PWS to monitor disinfectant residuals in the distribution system can 

21 allow the PWS to determine if there is an area of possible contamination or an area that requires 

22 additional treatment. Low levels of disinfectant residuals in a system can be caused by an 

23 increase of organics in a system, which consume disinfectant residuals, or insufficient 

24 disinfectant dosages at the treatment facility. Maintenance of sufficient disinfectant residual 

25 levels in a distribution system is important in maintaining minimal levels of total coliforms in the 

26 system. 

27

28 Disinfectant residual can be monitored using routine grab samples, with adjustment of 

29 dosages based on results. Controlling and monitoring disinfectant dosages and water quality 

30 parameters can also be performed through the use of a Supervisory Control and Data Acquisition 

31 (SCADA) system at the treatment facility. Disinfectant dosing equipment can be monitored and 

32 analyzers can be placed in the treatment process to monitor water quality parameters. 

33 Monitoring water quality parameters via SCADA in a distribution system is possible; however, it 

34 can be costly. Determining the number and location of the analyzers is challenging and highly 

35 dependent upon the system size. Typically, analyzer equipment will draw samples from an 

36 above grade pipe or a sample tap to an analyzer that is placed in a building. Sample locations 

37 will require analyzer equipment, a building, electric power, and, in the case of some systems, 

38 integration to the PWS’s existing SCADA system. Method requirements for on-line 

39 amperometric chlorine monitors are more time intensive and difficult than grab sampling. 

40 

41 Pressure Monitoring and Control 

42

43 In addition to water quality monitoring, a PWS can monitor pressure levels throughout 

44 the distribution system. Installing online pressure monitoring and control will help minimize 

45 future incidents of pressure loss that can allow entry of contaminants into the distribution system. 

46 It can also help determine if there are any physical problems in the system, e.g., a crack in a pipe, 

47 a leaking valve, etc., that cause changes to the water quality of the system. Pressure readings can 

48 also be used to help locate areas of deficiency in a distribution system. Similar to the water 

49 quality monitoring, determining the number of pressure monitors and their locations is dependent 
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1 upon the system size. Pressure monitoring locations will also require the same equipment as 

2 water quality sampling locations. 

3

4 On-line distribution system monitoring through the SCADA system can alert operators if 

5 there are possible issues with the distribution system; however, monitoring the water quality or 

6 pressure will not identify the source of the contamination nor will it necessarily identify the 

7 location of the contamination. 

8

9 4.2.10 Addition of Security Measures 

10

11 Systems may need to install security measures in circumstances where the assessment or 

12 onsite inspection reveals vandalism or security breaches that could lead to water contamination. 

13 Measures that a water system may take to correct security breaches include installing a fence or 

14 locking buildings to restrict access to the system. Other possible security measures include 

15 employing a full time, on-site security staff and using alarms and cameras to detect security 

16 breaches. 

17

18 Water systems should prioritize their security measures and concentrate on the most 

19 vulnerable parts of the system, such as unstaffed facilities (e.g., finished water storage tanks). 

20 An important implementation issue is determining the extent to which the water system needs to 

21 be secured. This would depend on how widely spread the system/facility is, the number and 

22 complexity of the treatment trains, the extent of the watershed, the distance of the treatment plant 

23 from the influent wells, accessibility of the distribution system, etc. 

24

25 Installing security measures can increase the public’s confidence in the protection of their 

26 drinking water and indeed can provide substantial protection against vandalism that might result 

27 in contamination of the water. However, security measures are not always foolproof or absolute 

28 in combating vandalism or security breaches. 

29

30 4.2.11 Development and Implementation of an Operations Plan 

31

32 A water system should develop a distribution system operations plan to integrate all 

33 operations and maintenance functions to meet the goals of flow, pressure and water quality. The 

34 AWWA G200-04 standard describes the critical requirements for the effective operation and 

35 management of drinking water distribution systems. According to this standard, a water system 

36 should develop standard operating procedures (SOPs), comprehensive monitoring plans, routine 

37 inspections, and emergency response plans. 

38

39 Develop Standard Operating Procedures (SOPs) 

40

41 SOPs should be developed for each operation and maintenance function that affects 

42 system water quality (e.g., flushing programs, storage facility inspections). The water quality 

43 goals for both the distribution system and the particular function should be specified in the SOP. 

44 SOPs should be developed from information gathered from the various departments and crews 

45 involved in a given function. The SOPs should be written in terms that everybody will 

46 understand and they should include all activities needed to conduct the procedures, and describe 

47 the labor, equipment and materials needed to complete the activity. 

48

49 Develop Sampling Plan 
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Proposed Revised Total Coliform Rule 4-17 August 2010 

Assessments and Corrective Actions Guidance Manual 

1

2 The water system should establish a routine distribution system sampling plan that is 

3 representative of the entire distribution system. At a minimum, the sample sites should include 

4 sites required for regulatory compliance monitoring. Additional sites should be sampled as 

5 necessary to provide a complete picture of the water quality in the system. All samples should 

6 be collected in accordance with the latest edition of Standard Methods for the Examination of 

7 Water and Wastewater (APHA et al. 2005). 

8

9 Perform Routine Inspections 

10

11 Routine inspections of various distribution system components such as finished water 

12 storage facilities, water mains, pump stations, chemical storage facilities, valves, and fire 

13 hydrants are necessary to ensure high-quality water. The water systems should implement 

14 inspection and maintenance programs of these components as part of the SOPs. 

15

16 Develop Emergency Response Plan 

17

18 A written emergency response plan for the distribution system allows operating personnel 

19 to respond efficiently, effectively and rapidly to an emergency situation. Water quality system 

20 safety and reliability are improved if a water system has an emergency response plan. 

21

22 Utilize Appropriately Qualified Operators 

23

24 EPA established an operator certification program with minimum professional standards 

25 for the operation and maintenance of water systems. The EPA program issued guidelines that 

26 specify standards for certification and recertification of operators. States implement the 

27 minimum standards of the certification program guidelines. While the specific requirements 

28 vary from state to state, the goal of the program is to ensure that skilled professionals are 

29 overseeing the treatment and distribution of safe drinking water and compliance with the Safe 

30 Drinking Water Act. More information on the operator certification program can be found at: 

31 http://www.epa.gov/safewater/operatorcertification/index.html. 

32

33 Providing training sessions for operators reinforce proper operation and maintenance of 

34 these facilities and systems. These sessions can also help educate PWS staff on emerging 

35 treatment technologies, regulatory requirements, and other advances in the drinking water 

36 industry. 

37

38 4.3 Best Practices 

39

40 Best practices are actions that systems should and/or might choose to take following a 

41 Level 1 or Level 2 trigger regardless of whether a sanitary defect or likely cause is identified, or 

42 following any total coliform or E. coli occurrence (e.g., a single E. coli-positive sample). They 

43 can range from temporary measures to long term measures. 

44

45 In the survey conducted by AWWA, AMWA, ASDWA (see footnote 8), most 

46 respondents indicated that follow-up actions are taken following a positive coliform result even 

47 when the underlying cause is unidentified. Systems take these actions to ensure public health 

48 protection and generally do not involve major construction or capital improvement. Examples of 

49 common actions that were reported are flushing, increasing disinfectant residual, collecting 
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Proposed Revised Total Coliform Rule 4-18 August 2010 

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1 additional investigative samples, examining whether samples were collected from appropriate 

2 sample sites, and re-training staff/sampler on proper sampling procedures. Based on the results 

3 of the survey, the list below includes these actions and a few other ones as examples of best 

4 practices that systems may take following an assessment trigger or a positive coliform result, 

5 regardless of whether the cause or the sanitary defect is identified. Some of them have already 

6 been discussed in Chapter 4.2 of this document. These actions are not mutually exclusive and 

7 systems may choose to implement a combination of them if appropriate. Systems should also 

8 consider implications for long-term sustainability and public health protection when deciding 

9 which of these actions to implement. 

10

11 The proposed RTCR also identifies a list of “best technologies, treatment techniques, or 

12 other means” (also known as best available technologies or BATs) to help systems comply with 

13 the rule (see §141.63(e) of the proposed RTCR). They include appropriate well placement and 

14 construction, maintenance of a disinfectant residual throughout the distribution system, proper 

15 maintenance of the distribution system, filtration and disinfection of surface water, 

16 implementation of a cross-connection control program, and implementation of a wellhead 

17 protection program. Systems may choose to take advantage of these BATs when they trigger an 

18 assessment in order to avoid future triggers and/or violations, even if they are unable to find a 

19 likely cause/sanitary defect. Some of these BATs are also discussed in the list below. 

20

21 • Apply disinfection – A discussion of disinfection practices is in Chapter 4.2.1 of this 

22 document. Additional information on emergency disinfection practices can be found at 

23 http://www.epa.gov/safewater/faq/emerg.html

24

25 • Change or update distribution system maintenance operations – A well-maintained and 

26 operated distribution system is an important barrier in protecting water quality. Even if 

27 water from an extremely clean source is adequately treated, breakdowns in the 

28 distribution system can lead to waterborne illnesses. In particular, the contamination of 

29 treated water can result from main breaks, inadequate water pressure that allows intrusion 

30 or backflow of contaminants, deficiencies in storage tanks, and inadequate separation of 

31 water supply lines and sewers. 

32

33 Proper maintenance of the distribution system includes appropriate pipe replacement and 

34 repair procedures, main flushing programs, proper operation and maintenance of storage 

35 tanks and reservoirs, cross-connection control, and continual maintenance of positive 

36 water pressure in all parts of the distribution system. Even if a Level 1 or Level 2 

37 assessment does not reveal an underlying cause for the positive coliform samples, many 

38 systems may choose to change or update their distribution system maintenance operations 

39 as a follow-up action. Many of these actions are described in Chapters 4.2.3 to 4.2.7 of 

40 this document. 

41

42 • Perform unscheduled or spot flushing – A discussion of unscheduled or spot flushing is 

43 in Chapter 4.2.2 of this document. 

44

45 • Implement sampler training – A discussion of sampler training is in Chapter 4.2.8 of this 

46 document. 

47
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Proposed Revised Total Coliform Rule 4-19 August 2010 

Assessments and Corrective Actions Guidance Manual 

1 • Review sample siting plan – The sample siting plan should ensure that the quality of the 

2 water is representative of the distribution system. Utilities might consider reviewing and 

3 revising their sample siting plan as a universal follow-up action, regardless of whether an 

4 underlying cause for the positive coliform samples can be identified. 

5

6 • Select appropriate sample sites – Part of a successful sampling plan is the selection of 

7 clean, appropriate sample taps and sites from which to collect representative samples. In 

8 addition to reviewing the sample siting plan, systems may wish to consider the use of 

9 dedicated sample taps, which is discussed in Chapter 4.2.3 of this document. 

10

11 • Institute boil water orders – A number of systems have chosen to institute boil water 

12 orders even in cases where total coliforms are detected but no E. coli is present. In some 

13 States, boil water orders are a required follow-up action after a total coliform-positive 

14 sample has occurred. However, it should be noted that requirements vary from state to 

15 state and systems should follow State requirements for implementing boil water orders, 

16 whether they are required in response to a total coliform-positive or not. 

17

18 A boil water order requires that systems publicly advertise that water should be boiled 

19 prior to consumption. While a boil water order can be protective of public health, it also 

20 requires effort for consumers, has economic impacts to businesses, and can undermine 

21 public confidence in the water supply. Therefore a boil water order should not be 

22 implemented lightly and should be reserved for situations with significant potential to 

23 impact public health. A Level 2 trigger associated with an E. coli-positive may be more 

24 appropriate for a boil water order action than a Level 1 trigger associated with a total 

25 coliform-positive. Boil water orders may also be issued on a voluntary basis and may be 

26 helpful for educating sensitive populations. 

27

28 4.4 Simultaneous Compliance Issues 

29

30 As mentioned previously, the interrelated nature of regulations can be a challenge as 

31 adjustments to improve compliance for one rule may inadvertently affect a system’s ability to 

32 comply with another rule. Given that temporary disinfection is a common corrective action 

33 taken by systems that have experienced positive coliform results, a number of related issues are 

34 important to keep in mind. 

35

36 NTNCWSs and CWSs that do not typically practice disinfection and are planning on 

37 adding temporary disinfection are subject to the Stage 1 and Stage 2 Disinfectants/Disinfection 

38 By-Products Rules (DBPRs) (40 CFR 141.130 and 141.600) (USEPA 1998b; USEPA 2006a) for 

39 the monitoring period in which the disinfectant is used. Systems should check with their States 

40 to determine what the requirements are for compliance with the rules. For temporary 

41 disinfection by chlorine or chloramines, the system will have to ensure that maximum residual 

42 disinfectant levels (MRDLs) for chlorine/chloramines and maximum contaminant levels (MCLs) 

43 for total trihalomethanes (TTHM) and the group of five haloacetic acids (HAA5) are not 

44 exceeded. 

45

46 Alkalinity and pH adjustment and/or the addition of corrosion inhibitors are often used to 

47 meet Lead and Copper Rule (LCR) (40 CFR Part 141, Subpart I) requirements. Systems that are 

48 using measures such as these should also be aware that the pH of the water can alter the efficacy 

49 of the disinfectant. For a given level of inactivation, the higher the pH, the higher the 
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Proposed Revised Total Coliform Rule 4-20 August 2010 

Assessments and Corrective Actions Guidance Manual 

1 disinfection detention time and/or chlorine residual concentration required. See Revised 

2 Guidance Manual for Selecting Lead and Copper Control Strategies (USEPA 2003) for more 

3 information on simultaneous compliance with the LCR and other drinking water regulations. 

4

5 Systems should also be aware that changes in disinfectant residual may alter the 

6 corrosivity of the water. Chlorine is a powerful oxidant and reacts with many metals that are 

7 present in the distribution system. Rapid changes between high concentrations and low (or no) 

8 concentrations of oxidants can destabilize metal scales that form along the pipe wall, possibly 

9 allowing for metal release into the water. 

10

11

12
Proposed Revised Total Coliform Rule 5-1 July 2010 

Assessments and Corrective Actions Guidance Manual

5. References 

American Public Health Association (APHA), Water Environment Federation (WEF), and American 

Water Works Association (AWWA). 2005. Standard Methods for the Examination of Water and 

Wastewater, 21st Edition, Washington, DC . 

AWWA, 1996. Water Transmission and Distribution. Denver, CO. AWWA 

AWWA, 2004. G200 –Standard for Distribution Systems Operation and Management. Denver, CO. 

AWWA, 2008. Reliable Coliform Sampling for Water Systems, DVD, Denver, CO. 

AWWA and AwwaRF. 1992. Water Industry Data Base: Utility Profiles. Denver, CO. 

Brandt, M. J., J. Clement, J. Powell, R. Casey, D. Holt, N. Harris, and C.T. Ta. 2004. Managing 

Distribution System Retention Time to Improve Water Quality, Denver, CO: AWWARF. 

Clark, R.M., E.E. Geldreich, K.R. Fox, E.W. Rice, C.H. Johnson, J.A. Goodrich, J.A. Barnick, F. 

Abdesaken, J.E. Hill, and F.J. Angulo. 1996. A Waterborne Salmonella typhimurium outbreak in 

Gideon, Missouri: results from a field investigation, International Journal of Environmental 

Health Research 6:187-193. 

Edberg, S.C., E.W. Rice, R.J. Karlin and M. J. Allen. 2000. Escherichia coli: the best biological drinking 

water indicator for public health protection. Journal of Applied Microbiology 88:106S-116S. 

Great Lakes – Upper Mississippi River Board of State and Provincial Public Health and Environmental 

Managers, Water Supply Committee. 2007. Recommended Standards for Water Works. Albany, 

NY. Available at: http://10statesstandards.com/waterstandards.html [30 Jul 2010]. 

Helmi, K., S. Skraber, C. Gantzer, R. Willame, L. Hoffmann, and H.M. Cauchie. 2008. Interactions of 

Cryptosporidium parvum, Giardia lamblia, vaccinal poliovirus type 1, and bacteriophages 

phiX174 and MS2 with a drinking water biofilm and a wastewater biofilm. Applied and 

Environmental Microbiology. 74:2079-2088. 

Kirmeyer, G.J and M. Friedman. 2000. Guidance Manual for Maintaining Distribution System Water 

Quality. Denver, CO: AWWARF and AWWA. 

Letterman, R.D., A. Amirtharajah, and C.R. O’Melia. 1999. Coagulation and Flocculation, in Water 

Quality and Treatment, 5th edition. R.D. Letterman, ed., AWWA, Denver, CO. 
Proposed Revised Total Coliform Rule 5-2 July 2010 

Assessments and Corrective Actions Guidance Manual

Lieberman, R.J., Shadix, L.C., Newport, B.S., Crout, S.R., Buescher, S.E., Safferman, R.S., Stetler, R.E., 

Lye, D., Fout, G.S., and Dahling, D. 1994. “Source water microbial quality of some vulnerable 

public ground water supplies.” Proceedings, Water Quality Technology Conference, San 

Francisco, CA, October, 1994. 

Lieberman, R., L. Shadix, B. Newport, and C. Frebis. 2002. Microbial Monitoring of Vulnerable Public 

Groundwater Supplies. American Water Works Association Research Foundation, Denver, CO. 

162 pp. 

Narasimhan, R., J. Brereton, M. Abbaszadegan, A. Alum, and P. Ghatpande. 2004. Sample Collection 

Procedures and Locations for Bacterial Compliance Monitoring, Awwa Research Foundation, 

Denver, CO. 

Rangel, J.M., P.H. Sparling, C. Crowe, P.M. Griffin and D.L. Swerdlow, 2005. Epidemiology of 

Escherichia coli O157:H7 outbreaks, United States, 1982-2002. Emerging Infectious Diseases 

11(4):603-609. 

Skraber, S., J. Schijven, C. Gantzer, and A.M. de Roda Husman. 2005. Pathogenic viruses in drinkingwater biofilms: a public health risk? Biofilms. 2:105-117. 

Stanford, B., A. Pisarenko, S. Snyder, and G. Gordon. The Formation of Perchlorate, Bromate, and Other 

Contaminants in Hypochlorite Solutions: Implications for Water Utilities. Proceedings from 

Water Quality Technology Conference & Expedition. Seattle, Washington. November 18, 2009. 

USEPA and California Department of Health Services. 1989. Water Distribution System Operation and 

Maintenance, A Field Study Training Program, 2nd ed. Hornet Foundation Inc., Sacramento, CA. 

USEPA. 1998a. National Primary Drinking Water Regulations: Interim Enhanced Surface Water 

Treatment Rule; Final Rule. 63 FR 23361 (April 28, 1998). 

USEPA. 1998b. National Primary Drinking Water Regulations: Stage 1 Disinfectant Disinfection 

Byproduct Rule; Final Rule. 63 FR 69390. (December 16, 1998). 

USEPA. 2001. A Small Systems Guide to the Total Coliform Rule (EPA 816-R-01-017a). Available at: 

http://www.epa.gov/safewater/disinfection/tcr/pdfs/guide_tcr_smallystemsguide.pdf [21 Jun 

2010]. 
Proposed Revised Total Coliform Rule 5-3 July 2010 

Assessments and Corrective Actions Guidance Manual

USEPA. 2003. Revised Guidance Manual for Selecting Lead and Copper Control Strategies (EPA-816-R03-001). Available at 

http://www.epa.gov/ogwdw/lcrmr/pdfs/guidance_lcmr_control_stratageis_revised.pdf [20 Jul 

2010]. 

USEPA. 2006a. National Primary Drinking Water Regulations: Stage 2 Disinfectant Disinfection 

Byproduct Rule; Final Rule. 71 FR 388. (January 4, 2006). 

USEPA. 2006b. National Primary Drinking Water Regulations: Ground Water Rule; Final Rule. 71 FR 

65574. (November 8, 2006). 

USEPA. 2006c. Total Coliform Rule White Paper: Causes of Total Coliform-Positive Occurrences in 

Distribution Systems. Available at: 

http://www.epa.gov/safewater/disinfection/tcr/pdfs/issuepaper_tcr_causes.pdf [23 Mar 2010]. 

USEPA. 2006d. Total Coliform Rule: A Handbook for Small Noncommunity Water Systems serving less 

than 3,300 persons: One of the Simple Tools for Effective Performance (STEP) Guide Series 

(EPA 816-B-06-001). Available at: 

http://www.epa.gov/safewater/disinfection/tcr/pdfs/stepguide_tcr_smallsys-3300.pdf [21 Jun 

2010] 

USEPA. 2006e. EPA’s Interactive Sampling Guide for Drinking Water Operators (CD-ROM). EPA-816-

C-06-001. http://www.epa.gov/ogwdw000/smallsystems/samplingcd.html#one [30 Jul 2010]. 

USEPA. 2008. Total Coliform Rule / Distribution System (TCRDS) Federal Advisory Committee 

Agreement In Principle. Available at: 

http://www.epa.gov/safewater/disinfection/tcr/pdfs/tcrdsac/agreementinprinciple_tcrdsac_2008-

09-18.pdf [24 Mar 2010]. 

USEPA. 2010a. Technology and Cost Document for the Proposed Revised Total Coliform Rule. EPA815-R-10-002. 

USEPA. 2010b. National Primary Drinking Water Regulations: Revisions to the Total Coliform Rule.75 

FR 40926. (July 14, 2010). 
A-1 

Appendix A 

Example Assessment Forms

The following are examples of Level 1 and Level 2 assessment forms developed by the Total 

Coliform Rule Distribution System Advisory Committee Technical Work Group. 

 
A-2 

THIS PAGE INTENTIONALLY LEFT BLANK 
CONCEPT EXAMPLE 

Level 1 Assessment Form

A-3 A-3 

System Name: Source Water: PWSID # System Type: Population Served: PWS AddrOperator in Responsible Charge (ORC): Phone: City, State: County: Person that collected TC samples if different than ORC: Phone: Address, City, State, Zip: Date Assessment Completed: 

Questions (1-5) 

Reviewed and 

checked? 

(Type “3” if 

completed or 

“N/A”) 

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

1. Have any of the following occurred at relevant facilities prior to the collection of TC samples? -any interruptions in the treatment process  -any reported loss of pressure events (pressure < 5 psi)  -operation and maintenance activities that could have introduced total coliform 

 -reported vandalism and/or unauthorized access to facilities  -visible indicators of unsanitary conditions reported  -any fire fighting event, flushing operation, sheared hydrant, etc.  -any sites with low or inadequate disinfectant residual or sites where it is difficult to maintain a residual  -any other water quality parameters measured where results were out of the ordinary 

2. Have there been any recent operational changes to the system?

-sources introduced 

 -treatment or operational changes  -potential sources of contamination

3. Evaluate sample site. 

-condition or location of tap 

 -regular use of connection

4. Sample protocol followed and reviewed.

-flush tap 

 -remove aerator  -no swivel  -fresh sample bottles  -sample storage acceptable

5. Distribution System

-system pressure 

 -cross connection  -pump station  -air relief valves  -fire hydrants or blow off  -breaks  -repairs
CONCEPT EXAMPLE 

Level 1 Assessment Form

A-4 A-4 

Questions (1-5) 

Reviewed and 

checked? 

(Type “3” if 

completed or 

“N/A”) 

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

6. Storage Tank 

-screens 

 -security  -access opening  -condition of tank  -vent  -drain overflow  -pressure tank  -O&M

7. Treatment Process  -interruptions  -POE/POU  -softeners  -O&M8. Source - Well 

-sanitary seal -vent screened 

 -air gap  -cross connection  -security  -pump to waste line

9. Source - Spring 

-condition of spring development 

 -condition of spring box  -security

10. Source - Surface Water Supply  -heavy rainfall  -rapid snowmeltNote: Form to be completed based on data and documents available to the PWS operator in charge, maintained on file and returned to the Primacy Agency within XX days. Additional Comments: Print name of person completing form: Date: Signature: Reserved for State 1. Assessment has been successfully completed. 2. Likely reason for total coliform-positive occurrence is established. 3. System has corrected the problem. 4. Was a reset requested and / or granted? – Rationale 5. Name of State reviewer: 
CONCEPT EXAMPLE 

Level 2 Assessment Form

A-5 A-5 

System Name: Source Water: PWSSystem Type: Population Served: PWS Operator in Responsible Charge (ORC): Phone: City, State: County: Person that collected TC samples if different than ORC: Phone: Address, City, State, Zip: Date Assessment Completed: 

Questions 

Reviewed and 

checked? (Type 

“3” if 

completed or 

“N/A”)

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

1. Have any of the following occurred at relevant facilities prior to the collection of TC samples? a. Were there any operation and maintenance activities that could have introduced total coliforms? b. Have there been any interruptions in the treatment process? c. Has the system lost pressure to less than 5 psi? d. Have there been any vandalism and/or unauthorized access to facilities? e. Are there any visible indicators of unsanitary conditions observed? f. 

Have there been any analytical results or any additional samples collected, including source samples which were positive (not for compliance)? 

g. 

Have there been any sites with low or inadequate disinfectant residual? Are there sites where it is difficult to maintain a residual without flushing? 

h. Were any other water quality parameters measured and were any results out of the ordinary? i. 

Have there been any community illness suspected of being waterborne (e.g., Does the community public health official indicate 

that an outbreak has occurred.) 

j. Did the water system receive any TCR monitoring violations in the past 12 months? If yes, when. k. What was the most recent date on which satisfactory total coliform samples were taken? Date: ______________ l. Have there been a fire fighting event, flushing operation, sheared hydrant, etc. m. Other comments on records and maintenance? 
CONCEPT EXAMPLE 

Level 2 Assessment Form

A-6 A-6 

Questions 

Reviewed and 

checked? (Type 

“3” if 

completed or 

“N/A”)

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

2. Have there been any recent treatment or operational changes? a. Have any inactive sources recently been introduced into the system (e.g., auxiliary systems)? b. Have there been any new sources introduced into the system? c. Is there evidence of any potential sources of contamination (main breaks, low pressure, high turbidity, loss of disinfection, etc.)? 3. Evaluate sample site a. What is the condition of the tap? (Provide comments)b. What is the location of the tap? (Provide comments)c. What is the regular use of the connection? (Provide comments)d. Have there been any plumbing changes or construction? If yes, when and what was the repair or change? e. Have there been any plumbing breaks or failure? If yes, when? f. 

List any identified cross connections after the service connection or in premise plumbing. (Provide comments)

g. Were all of the backflow prevention devices present, operational and maintained? h. 

Were there any low pressure events or changes in water pressure after the service connection or in the premise plumbing? If yes, when? 

i. 

Is there any treatment devices after the service connection or in premise? (Circle response, if applicable)

Point of Entry (POE) Point of Use (POU) 

j. Other comments on sample site? 4. Sample protocol followed and reviewed a. Flush tap, remove aerator, no swivel, fresh sample bottles, sample storage acceptable 5. Distribution System a. System pressure: Is there evidence that the system experienced low or negative pressure? If yes, when? b. List any identified cross connections. c. Pump station: Are there any sanitary defects in the pump station? Are pump(s) operable? 
CONCEPT EXAMPLE 

Level 2 Assessment Form

A-7 A-7 

Questions 

Reviewed and 

checked? (Type 

“3” if 

completed or 

“N/A”)

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

d. Last pump maintenance/service date. (Respond if applicable) Date: _____________ Maintenance Performed? e. 

Air relief valves: Is the valve vault subject to flooding or does the vent terminate below grade? 

f. Fire hydrant/blow off: Are any located in an area with a high water table or pits? g. Is the distribution system secured to prevent unauthorized access? h. Are the backflow prevention devices at high risk sites present, operational and maintained? i. Have there been any water main repairs or additions? If yes when, and what was the repair or addition? j. Have there been any water main breaks? If yes, when? k. Was there any scheduled flushing of the distribution system? If yes, when? l. Is there any evidence of intentional contamination in the distribution system? m. Other comments on the distribution information. 6. Storage Facilities a. Are the overflow and vents properly screened? b. Is the facility secured to prevent unauthorized access? c. Does the access opening have the proper gasket and seal tightly? d. Could the physical condition of tank be a source of contamination? e. Is the vent turned down and maintaining an approved air gap at the termination point? f. Does the drain/overflow line terminate at a minimum of 12" air gap? g. If present, is the pressure tank maintaining an appropriate minimum pressure? h. Has proper O&M been performed? i. Was there any observed physical deterioration of the tank? j. Were there any observed leaks? k. Is there any evidence of intentional contamination at the storage tank? l. Has there been any facility maintenance (i.e. painting/coating)? If yes, when? 
CONCEPT EXAMPLE 

Level 2 Assessment Form

A-8 A-8 

Questions 

Reviewed and 

checked? (Type 

“3” if 

completed or 

“N/A”)

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

m. Is facility maintenance occurring per appropriate schedule? n. Does the tank "float" on the distribution system or are there separate inlet and outlet lines? o. What is the measured chlorine residual (total/free) of the water exiting the storage tank today? Residual ____________ p. Are there any unsealed openings in the storage facility such as access doors, vents or joints? q. Other comments on the storage system 7. Treatment Process. (If applicable) a. Treatment devices operational and maintained? b. Is there any recent installation or repair of treatment equipment? c. 

Were there any recent changes in the treatment process (e.g., addition of a process, change in chemical or dosage)? If yes, when, what was the change? 

d. 

Were there any interruptions of treatment (lapses in chemical feed, turbidity excursions, disinfection)? If yes which part, when and for how long? 

e. What is the free chlorine residual measured immediately downstream from the point of application? Residual: ____________ f. Did a review of the filter turbidity profiles reveal any anomalies? g. Were there any failures to meet the C x T calculations? h. Were the flow rates above the rated capacity? i. Were there any anomalies on the settled water turbidities? j. Other comments on the treatment system. 8. Source – Well a. Is the sanitary seal intact? b. Is the vent screened? c. Does the vent and pump to waste terminate in an approved air gap? d. Are there any unprotected cross connections at the wellhead? e. 

How is the well used? (Circle if applicable) Primary Backup Emergency Not a PWS Not Drinking W

f. How far does the casing extend above grade? Height ____________ Comments: 
CONCEPT EXAMPLE 

Level 2 Assessment Form

A-9 A-9 

Questions 

Reviewed and 

checked? (Type 

“3” if 

completed or 

“N/A”)

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

g. Is the well cap vented? h. Is there evidence of standing water near the wellhead? i. Is the wellhead secured to prevent unauthorized access? j. Have there been any sewer spills, source water spills or other disturbances? k. Other comments on the well system. (Are there aspects of well construction and operation that would bear on observed positives?) 9. Source – Spring a. What is the condition of the spring development? b. What is the condition of the spring box? c. Is the spring secured to prevent unauthorized access? d. Other comments on the spring system. 10. Source - Surface Water Supply a. Have there been any sewer spills, source water spills or other disturbances? b. Have there been any algal blooms? c. Has source water turnover occurred? d. Other source water comments Environmental Events a. Has there been heavy rainfall? b. Has there been any rapid snow melt or flooding? c. Have there been changes in available source water (e.g., significant drop in water table, well levels, reservoir capacity, etc.) d. Have there been any interruptions to electrical power? e. Have there been any extremes in heat or cold? Note : Form to be completed based on data and documents available to the PWS operator in charge, maintained on file and returned to the Primacy Agency within Additional Comments: 
CONCEPT EXAMPLE 

Level 2 Assessment Form

A- A-10 

Print name of person completing form: Date: Signature: Reserved for State 

1. Assessment has been successfully completed. Name of State Reviewer: 
B-1 

Appendix B 

Examples of Completed Assessments 

This appendix provides examples of completed Level 1 and Level 2 assessment forms (using the 

forms presented in Appendix A). Some States are already requiring some form of assessment 

and the completion of an assessment form whenever a PWS has a total coliform-positive sample. 

Those States provided EPA with some of the completed assessments performed by their 

respective PWSs. EPA developed the examples in this appendix based on the assessment forms 

provided by the States. Personal information about the PWS or any person mentioned in the 

example forms is fictitious in nature. They are provided to show the types of information that 

are expected to be included in the form. 

 
B-2 

Assessment Form Instructions 

1. Fill in system information under the first section of the form. The following information must 

be provided at a minimum: 

• System Name 

• Source Water (GW, SW, GWUDI, Purchased) 

• System Type (CWS, NTNCWS, TNCWS) 

• Population Served 

• Operator in Responsible Charge (ORC) 

• Phone 

• City, State 

• PWSID # 

• PWS Address 

2. Respond to all Questions 1-10: 

• Type “3” in the box for the items that were reviewed and checked or “N/A” if the item is 

not applicable to the system. 

• Print “Yes” or “No” in the “Issue(s) found?” column. 

• Describe any issues found and corrective action taken. 

• Be sure to include dates of any corrective actions taken. 

3. Sign and date form on last page. Form must be completed based on data and documents 

available to the PWS operator in charge, maintained on file, and sent to the primacy agency 

within XX days.

 
B-3 

Example No. 1 – Level 1 Assessment 

UTILITY PROFILE 

Buttermilk Falls Country Club is a non-transient, non-community water system that gets its 

water from a ground water source. It collects 1 routine sample per month. The system does not 

have any records of past violations. 

DESCRIPTION OF THE PROBLEM 

In November 2009, the routine monthly sample and one of its associated repeat samples came 

back positive for total coliforms. This triggered a Level 1 assessment. 

ASSESSMENT AND CORRECTIVE ACTION 

All applicable items listed in the Level 1 assessment form were all checked. Nothing unusual 

was found and all of the subsequent repeat samples came back negative. 

 
B-4 

THIS PAGE INTENTIONALLY LEFT BLANK
CONCEPT EXAMPLE NO. 1 

Level 1 Assessment Form 

 B-5 

System Name: Buttermilk Falls Country Club Source Water: Ground Water PWSID # 1System Type: NTNCWS Population Served: 120 PWS AddrOperator in Responsible Charge (ORC): J. Griffin Phone: 012-345-6789 123 AnywCity, State: Buttermilk Falls, MS County: Hoover Person that collected TC samples if different than ORC: C. Gary, HHH Labs Phone: 123-456-7890 Address, City, State, Zip: 222 Second St., Buttermilk Falls, MS 12121Date Assessment Completed: 11/12/2009 

Questions (1-5) 

Reviewed and 

checked? 

(Type “3” if 

completed or 

“N/A”) 

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

1. Have any of the following occurred at relevant facilities prior to the collection of TC samples? -any interruptions in the treatment process  -any reported loss of pressure events (5 psi)  -operation and maintenance activities that could have introduced total coliform 

 -reported vandalism and/or unauthorized access to facilities  -visible indicators of unsanitary conditions reported  -Has there been a fire fighting event, flushing operation, sheared hydrant, etc.

9 No 

2. Have there been any recent operational changes to the system?

-sources introduced 

 -treatment or operational changes  -potential sources of contamination

9 No 

3. Evaluate sample site. 

-condition or location of tap 

 -regular use of connection

9 No 

4. Sample protocol followed and reviewed.

-flush tap 

 -remove aerator  -no swivel  -fresh sample bottles  -sample storage acceptable

9 No 

5. Distribution System

-system pressure 

 -cross connection  -pump station  -air relief valves  -fire hydrants or blow off  -breaks  -repairs

9 No 
CONCEPT EXAMPLE NO. 1 

Level 1 Assessment Form 

 B-6 

Questions (1-5) 

Reviewed and 

checked? 

(Type “3” if 

completed or 

“N/A”) 

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

6. Storage Tank 

-screens 

 -security  -access opening  -condition of tank  -vent  -drain overflow  -pressure tank  -O&M

N/A 

7. Treatment Process  -interruptions  -POE/POU  -softeners  -O&M

N/A 

8. Source - Well 

-sanitary seal -vent screened 

 -air gap  -cross connection  -security  -pump to waste line

9 No 

9. Source - Spring 

-condition of spring development 

 -condition of spring box  -security

N/A 

10. Source - Surface Water Supply  -heavy rainfall  -rapid snowmelt

N/A 

Note: Form to be completed based on data and documents available to the PWS operator in charge, maintained on file and returned to the Primacy Agency within XX days. 

Additional Comments: At this time, the obvious cause of the total coliform‐positive results has not been identified.

Print name of person completing form: Betty Sutherland Date: 11-12-09 Signature: Reserved for State 1. Assessment has been successfully completed. 2. Likely reason for total coliform positive- occurrence is established. 3. System has corrected the problem. 4. Was a reset requested and / or granted? – Rationale 5. Name of State reviewer: 
B-7 

Example No. 2 – Level 1 Assessment 

UTILITY PROFILE 

Silver Lake is a mid-sized community water system that supplies treated ground water to 

approximately 24,200 people. It collects 25 routine samples per month. 

DESCRIPTION OF THE PROBLEM 

The system received a notice of violation for failing to take all of the required repeat samples 

after a total coliform-positive sample was detected, triggering the system to have a Level 1 

assessment. 

ASSESSMENT AND CORRECTIVE ACTION 

Upon thorough inspection of the distribution system, an air release valve was found submerged 

in a flooded valve vault. A permanent sump pump will be installed in the vault based on a 

schedule approved by the State. Shock chlorination measures were performed in accordance 

with State guidelines on the portion of the line where the air release valve was located. 

 
B-8 

THIS PAGE INTENTIONALLY LEFT BLANK
CONCEPT EXAMPLE NO. 2 

Level 1 Assessment Form 

B-9 

System Name: Silver Lake Source Water: Ground Water PWSID # 2System Type: CWS Population Served: 24,200 PWS AddrOperator in Responsible Charge (ORC): J. Troy Phone: 012-345-6789 123 AnywCity, State: Silver Lake, MI County: Hamilton Person that collected TC samples if different than ORC: B. Black, CDE Labs Phone: 123-456-7890Address, City, State, Zip: 111 First St., Gold Water, MI 20000 Date Assessment Completed: 02/12/2010 

Questions (1-5) 

Reviewed and 

checked? 

(Type “3” if 

completed or 

“N/A”) 

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

1. Have any of the following occurred at relevant facilities prior to the collection of TC samples? -any interruptions in the treatment process  -any reported loss of pressure events (5 psi)  -operation and maintenance activities that could have introduced total coliform 

 -reported vandalism and/or unauthorized access to facilities  -visible indicators of unsanitary conditions reported  -Has there been a fire fighting event, flushing operation, sheared hydrant, etc.

9 No 

2. Have there been any recent operational changes to the system?

-sources introduced 

 -treatment or operational changes  -potential sources of contamination

9 No 

3. Evaluate sample site. 

-condition or location of tap 

 -regular use of connection

9 No 

4. Sample protocol followed and reviewed.

-flush tap 

 -remove aerator  -no swivel  -fresh sample bottles  -sample storage acceptable

9 No 

5. Distribution System

-system pressure 

 -cross connection  -pump station  -air relief valves  -fire hydrants or blow off  -breaks  -repairs

9 Yes 

Visual inspection of distribution system conducted on 2/11/10 revealed a potential contamination source at end of distribution system. An air release valve was found submerged in a flooded vault.

Sump pump on 2/20/1030-day periaccordance where air v
CONCEPT EXAMPLE NO. 2 

Level 1 Assessment Form 

B-10 

Questions (1-5) 

Reviewed and 

checked? 

(Type “3” if 

completed or 

“N/A”) 

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

6. Storage Tank 

-screens 

 -security  -access opening  -condition of tank  -vent  -drain overflow  -pressure tank  -O&M

9 No 

7. Treatment Process  -interruptions  -POE/POU  -softeners  -O&M

9 No 

8. Source - Well 

-sanitary seal -vent screened 

 -air gap  -cross connection  -security  -pump to waste line

9 No 

9. Source - Spring 

-condition of spring development 

 -condition of spring box  -security

N/A 

10. Source - Surface Water Supply  -heavy rainfall  -rapid snowmelt

N/A 

Note: Form to be completed based on data and documents available to the PWS operator in charge, maintained on file and returned to the Primacy Agency within XX days. 

Additional Comments: 

Print name of person completing form: Adam Lockland Date: 02-12-2010 Signature: Reserved for State 1. Assessment has been successfully completed. 2. Likely reason for total coliform-positive occurrence is established. 3. System has corrected the problem. 4. Was a reset requested and / or granted? – Rationale 5. Name of State reviewer: 
B-11 

Example No. 3 – Level 1 Assessment 

UTILITY PROFILE 

Eagle Cliff is a community water system that receives its water from a spring source and serves 

5,500 people. It collects 6 routine samples per month. 

DESCRIPTION OF THE PROBLEM 

In July 2009, the routine sample and one of its associated repeat samples both came back total 

coliform-positive triggering a Level 1 assessment. 

ASSESSMENT AND CORRECTIVE ACTION 

Upon inspection of the distribution system piping, small factures were found in the water main 

leading from the spring source to a water tank. The piping was replaced and additional samples 

were taken to determine whether coliforms were still present in the system. The results came 

back negative. 

 
B-12 

THIS PAGE INTENTIONALLY LEFT BLANK
CONCEPT EXAMPLE NO. 3 

Level 1 Assessment Form 

B-13 

System Name: Eagle Cliff Source Water: Spring PWSID # 3System Type: CWS Population Served: 5,500 PWS AddrOperator in Responsible Charge (ORC): F. Langdon Phone: 012-345-6789 456 AnywaCity, State: Eagle Cliff, AL County: Hoover Person that collected TC samples if different than ORC: C. Heart Phone: 123-456-7890 Address, City, State, Zip: 333 Third St., Eagle Cliff, AL 10000 Date Assessment Completed: 9/1/2009 

Questions (1-5) 

Reviewed and 

checked? 

(Type “3” if 

completed or 

“N/A”) 

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

1. Have any of the following occurred at relevant facilities prior to the collection of TC samples? -any interruptions in the treatment process  -any reported loss of pressure events (5 psi)  -operation and maintenance activities that could have introduced total coliform 

 -reported vandalism and/or unauthorized access to facilities  -visible indicators of unsanitary conditions reported  -Has there been a fire fighting event, flushing operation, sheared hydrant, etc.

9 No 

2. Have there been any recent operational changes to the system?

-sources introduced 

 -treatment or operational changes  -potential sources of contamination

9 No 

3. Evaluate sample site. 

-condition or location of tap 

 -regular use of connection

9 No 

4. Sample protocol followed and reviewed.

-flush tap 

 -remove aerator  -no swivel  -fresh sample bottles  -sample storage acceptable

9 No 

5. Distribution System

-system pressure 

 -cross connection  -pump station  -air relief valves  -fire hydrants or blow off  -breaks  -repairs

9 Yes Small fractures detected in raw water line from spring to tank. Raw water 
CONCEPT EXAMPLE NO. 3 

Level 1 Assessment Form 

B-14 

Questions (1-5) 

Reviewed and 

checked? 

(Type “3” if 

completed or 

“N/A”) 

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

6. Storage Tank 

-screens 

 -security  -access opening  -condition of tank  -vent  -drain overflow  -pressure tank  -O&M

9 No 

7. Treatment Process  -interruptions  -POE/POU  -softeners  -O&M

9 No 

8. Source - Well 

-sanitary seal -vent screened 

 -air gap  -cross connection  -security  -pump to waste line

N/A 

9. Source - Spring 

-condition of spring development 

 -condition of spring box  -security

9 No 

10. Source - Surface Water Supply  -heavy rainfall  -rapid snowmelt

N/A 

Note: Form to be completed based on data and documents available to the PWS operator in charge, maintained on file and returned to the Primacy Agency within XX days. 

Additional Comments: 

Print name of person completing form: Michael Taylor Date: 09-01-2009 Signature: Reserved for State 1. Assessment has been successfully completed. 2. Likely reason for total coliform-positive occurrence is established. 3. System has corrected the problem. 4. Was a reset requested and / or granted? – Rationale 5. Name of State reviewer: 
B-15 

Example No. 4 – Level 1 Assessment 

UTILITY PROFILE 

Eggleston Glen is a large municipal water system that is supplied by a ground water source under 

the direct influence of surface water (GWUDI). The system treats its water before serving it to 

its 985,000 customers. It collects over 300 routine samples per month. 

DESCRIPTION OF THE PROBLEM 

In August 2009, more than 5% of the monthly total coliform samples came back positive 

triggering a Level 1 assessment. Many of the positive samples were in the same general location 

in the distribution system and in proximity to a large ground storage tank. Several days prior to 

the collection of the positive samples, the system experienced pressure loss for a period of 4 

hours while the media in the GAC filters at one of the plants was being changed out. During this 

time the tank levels dropped to near empty. 

ASSESSMENT AND CORRECTIVE ACTION 

Normally stagnant water from the tank entered the distribution system during the pressure loss 

event causing the total coliform positive results. The tank was taken off-line, cleaned and shock 

chlorinated in accordance with State guidelines before putting it back on service. The 

distribution system near the tank was also flushed to improve water turnover. 

 
B-16 

THIS PAGE INTENTIONALLY LEFT BLANK
CONCEPT EXAMPLE NO. 4 

Level 1 Assessment Form 

B-17 

System Name: Eggleston Glen Source Water: GWUDI PWSID # 4System Type: CWS Population Served: 985,000 PWS AddrOperator in Responsible Charge (ORC): J. Griffin Phone: 012-345-6789 123 AnywaCity, State: Eggleston Glen, CO County: Hoover Person that collected TC samples if different than ORC: V. Lewis, GHG Labs Phone: 123-456-7890 Address, City, State, Zip: 444 Fourth St., Littletown, CO 20000 Date Assessment Completed: 8/28/2009 

Questions (1-5) 

Reviewed and 

checked? 

(Type “3” if 

completed or 

“N/A”) 

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

1. Have any of the following occurred at relevant facilities prior to the collection of TC samples? -any interruptions in the treatment process  -any reported loss of pressure events (5 psi)  -operation and maintenance activities that could have introduced total coliform 

 -reported vandalism and/or unauthorized access to facilities  -visible indicators of unsanitary conditions reported  -Has there been a fire fighting event, flushing operation, sheared hydrant, etc.

9 Yes 

Loss of system pressure for 4 hours while changing media in GAC filters. Tank level dropped to near empty. This may have allowed "old" water to enter the system from system tank. 

Distribution the tank to cleaned, anguidelines be checked month. 

2. Have there been any recent operational changes to the system?

-sources introduced 

 -treatment or operational changes  -potential sources of contamination

9 No 

3. Evaluate sample site. 

-condition or location of tap 

 -regular use of connection

9 No 

4. Sample protocol followed and reviewed.

-flush tap 

 -remove aerator  -no swivel  -fresh sample bottles  -sample storage acceptable

9 No 

5. Distribution System

-system pressure 

 -cross connection  -pump station  -air relief valves  -fire hydrants or blow off  -breaks  -repairs

9 No 
CONCEPT EXAMPLE NO. 4 

Level 1 Assessment Form 

B-18 

Questions (1-5) 

Reviewed and 

checked? 

(Type “3” if 

completed or 

“N/A”) 

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

6. Storage Tank 

-screens 

 -security  -access opening  -condition of tank  -vent  -drain overflow  -pressure tank  -O&M

9 No 

7. Treatment Process  -interruptions  -POE/POU  -softeners  -O&M

9 No 

8. Source - Well 

-sanitary seal -vent screened 

 -air gap  -cross connection  -security  -pump to waste line

9 Yes See item No. 1 

9. Source - Spring 

-condition of spring development 

 -condition of spring box  -security

9 No 

10. Source - Surface Water Supply  -heavy rainfall  -rapid snowmelt

N/A 

Note: Form to be completed based on data and documents available to the PWS operator in charge, maintained on file and returned to the Primacy Agency within XX days. 

Additional Comments: 

Print name of person completing form: John Gilmore Date: 08-28-2009 Signature: Reserved for State 1. Assessment has been successfully completed. 2. Likely reason for total coliform-positive occurrence is established. 3. System has corrected the problem. 4. Was a reset requested and / or granted? – Rationale 5. Name of State reviewer: 
B-19 

Example No. 5 – Level 2 Assessment 

UTILITY PROFILE 

Warsaw Falls is a community water system that gets its water from ground water sources. It 

serves a population of 2,550 people and collects 3 routine samples every month. 

DESCRIPTION OF THE PROBLEM 

In January 2010, the system had an E. coli MCL violation (a routine sample that was E. colipositive followed by a repeat sample that was total coliform-positive) that triggered a Level 2 

assessment. 

ASSESSMENT AND CORRECTIVE ACTION 

The Level 2 assessment revealed unsanitary conditions around one particular well that was 

located in a parking lot, which may or may not have been the source of the contamination. The 

system operator noted the need to re-locate or significantly improve the well due to its location 

and the poor condition of the well casing. The system coordinated with the State to develop 

interim measures and to work out a schedule to perform the remaining corrective action beyond 

the 30-day period. The pressure tank was also recently replaced but was not believed to be the 

source of the contamination as the whole system was shock chlorinated after the tank was 

replaced. 

 
B-20 

THIS PAGE INTENTIONALLY LEFT BLANK
CONCEPT EXAMPLE NO. 5 

Level 2 Assessment Form 

B-21 

System Name: Warsaw Falls Recreation Center Source Water: Ground Water PWSSystem Type: CWS Population Served: 2,550 PWS Operator in Responsible Charge (ORC): Peter Garrison Phone: 012-345-6789 123 City, State: Warsaw Falls, FL County: Ford Person that collected TC samples if different than ORC: J. Smith, ABC Labs Phone: 123-456-7890 Address, City, State, Zip: 012 Main St., Bigtown, FL 11111 Date Assessment Completed: 02/10/2010 

Questions 

Reviewed and 

checked? 

(Type “3” if 

completed or 

“N/A”) 

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

1. Have any of the following occurred at relevant facilities prior to the collection of TC samples? a. Were there any operation and maintenance activities that could have introduced total coliforms? 9 No b. Have there been any interruptions in the treatment process? 9 No c. Has the system lost pressure to less than 5 psi? 9 No d. Have there been any vandalism and/or unauthorized access to facilities? 9 No e. Are there any visible indicators of unsanitary conditions observed? 9 Yes Unsanitary conditions around well including garbage and parking lot run-off. See if. 

Have there been any analytical results or any additional samples collected, including source samples which were positive (not for compliance)? 

9 No 

g. 

Have there been any community illness suspected of being waterborne (e.g., Does the community public health official indicate 

that an outbreak has occurred.) 

9 No 

h. Did the water system receive any TCR monitoring violations in the past 12 months? If yes, when. 9 No i. What was the most recent date on which satisfactory total coliform samples were taken? Date: Dec 2009j. Have there been a fire fighting event, flushing operation, sheared hydrant, etc. 9 No k. Other comments on records and maintenance? None2. Have there been any recent treatment or operational changes? a. Have any inactive sources recently been introduced into the system (e.g., auxiliary systems)? 9 No 
CONCEPT EXAMPLE NO. 5 

Level 2 Assessment Form 

B-22 

Questions 

Reviewed and 

checked? 

(Type “3” if 

completed or 

“N/A”) 

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

b. Have there been any new sources introduced into the system? 9 No c. Is there evidence of any potential sources of contamination (main breaks, low pressure, high turbidity, loss of disinfection, etc.)? 9 No 3. Evaluate sample site a. What is the condition of the tap? (Provide comments) Good b. What is the location of the tap? (Provide comments) Good c. What is the regular use of the connection? (Provide comments) Raw water tap for sample collection d. Have there been any plumbing changes or construction? If yes, when and what was the repair or change? 9 No e. Have there been any plumbing breaks or failure? If yes, when? 9 No f. 

List any identified cross connections after the service connection or in premise plumbing. (Provide comments)

None 

g. Were all of the backflow prevention devices present, operational and maintained? 9 No h. 

Were there any low pressure events or changes in water pressure after the service connection or in the premise plumbing? If yes, when? 

9 No 

i. 

Is there any treatment devices after the service connection or in premise? (Circle response, if applicable)

Point of Entry (POE) Point of Use (POU) 

j. Other comments on sample site? None 4. Sample protocol followed and reviewed a. Flush tap, remove aerator, no swivel, fresh sample bottles, sample storage acceptable 9 No 5. Distribution System a. System pressure: Is there evidence that the system experienced low or negative pressure? If yes, when? 9 No b. List any identified cross connections. 9 No c. Pump station: Are there any sanitary defects in the pump station? Are pump(s) operable? 9 No d. Last pump maintenance/service date. (Respond if applicable) Date: 12/2006 Maintenance Performed? Mechanical seal replac
CONCEPT EXAMPLE NO. 5 

Level 2 Assessment Form 

B-23 

Questions 

Reviewed and 

checked? 

(Type “3” if 

completed or 

“N/A”) 

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

e. 

Air relief valves: Is the valve vault subject to flooding or does the vent terminate below grade? 

9 No 

f. Fire hydrant/blow off: Are any located in an area with a high water table or pits? 9 No g. Is the distribution system secured to prevent unauthorized access? 9 No h. Are the backflow prevention devices at high risk sites present, operational and maintained? 9 No i. Have there been any water main repairs or additions? If yes when, and what was the repair or addition? 9 No j. Have there been any water main breaks? If yes, when? 9 No k. Was there any scheduled flushing of the distribution system? If yes, when? 9 No l. Is there any evidence of intentional contamination in the distribution system? 9 No m. Other comments on the distribution information. None 6. Storage Facilities a. Are the overflow and vents properly screened? 9 No b. Is the facility secured to prevent unauthorized access? 9 No c. Does the access opening have the proper gasket and seal tightly? 9 No d. Could the physical condition of tank be a source of contamination? 9 No The pressure tank was recently replaced. 

Whotank corrwork 

e. Is the vent turned down and maintaining an approved air gap at the termination point? 9 No f. Does the drain/overflow line terminate at a minimum of 12" air gap? 9 No g. If present, is the pressure tank maintaining an appropriate minimum pressure? 9 No h. Has proper O&M been performed? 9 No i. Was there any observed physical deterioration of the tank? 9 No j. Were there any observed leaks? 9 No k. Is there any evidence of intentional contamination at the storage tank? 9 No l. Has there been any facility maintenance (i.e. painting/coating)? If yes, when? 9 No 
CONCEPT EXAMPLE NO. 5 

Level 2 Assessment Form 

B-24 

Questions 

Reviewed and 

checked? 

(Type “3” if 

completed or 

“N/A”) 

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

m. Is facility maintenance occurring per appropriate schedule? 9 No n. Does the tank "float" on the distribution system or are there separate inlet and outlet lines? 9 No o. What is the measured chlorine residual (total/free) of the water exiting the storage tank today? Residual N/Ap. Are there any unsealed openings in the storage facility such as access doors, vents or joints? 9 No q. Other comments on the storage system None 7. Treatment Process. (If applicable) a. Treatment devices operational and maintained? N/A b. Is there any recent installation or repair of treatment equipment? N/Ac. Were there any recent changes in the treatment process? If yes, when, what was the change? N/Ad. 

Were there any interruptions of treatment (lapses in chemical feed, turbidity excursions, disinfection)? If yes which part, when and for how long? 

N/A

e. What is the free chlorine residual measured immediately downstream from the point of application? Residual: N/Af. Did a review of the filter turbidity profiles reveal any anomalies? N/Ag. Were there any failures to meet the C x T calculations? N/Ah. Were the flow rates above the rated capacity? N/Ai. Were there any anomalies on the settled water turbidities? N/Aj. Other comments on the treatment system. None 8. Source – Well a. Is the sanitary seal intact? 9 No b. Is the vent screened? 9 No c. Does the vent and pump to waste terminate in an approved air gap? 9 No d. Are there any unprotected cross connections at the wellhead? 9 No e. 

How is the well used? (Circle if applicable) Primary Backup Emergency Not a PWS Not Drinking W
CONCEPT EXAMPLE NO. 5 

Level 2 Assessment Form 

B-25 

Questions 

Reviewed and 

checked? 

(Type “3” if 

completed or 

“N/A”) 

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

f. How far does the casing extend above grade? Height 14 inches Comments: g. Is the well cap vented? 9 No h. Is there evidence of standing water near the wellhead? 9 Yes After heavy rain events, there is standing water for a day or two. i. Is the wellhead secured to prevent unauthorized access? 9 No j. Have there been any sewer spills, source water spills or other disturbances? 9 No k. Other comments on the well system. (Are there aspects of well construction and operation that would bear on observed positives?) 

Well needs significant rehabilitation or relocation, requiring more than 30 days. Coordinschedule and interim measures. Well will be kept off-line to greatest extent possible, with disinfection to be applied at 2 mg/L whenever well is put on-line. Engineering feasibility recommendation and proposed completion schedule due to State by 3/10/10. Corrective aState by 3/25/10.

9. Source – Spring a. What is the condition of the spring development? N/A b. What is the condition of the spring box? N/Ac. Is the spring secured to prevent unauthorized access? N/Ad. Other comments on the spring system. None10. Source - Surface Water Supply a. Have there been any sewer spills, source water spills or other disturbances? N/Ab. Have there been any algal blooms? N/Ac. Has source water turnover occurred? N/Ad. Other source water comments None Environmental Events a. Has there been heavy rainfall? 9 Yes See Item 8. b. Has there been any rapid snow melt or flooding? 9 No c. Have there been changes in available source water (e.g., significant drop in water table, well levels, reservoir capacity, etc.) 9 No d. Have there been any interruptions to electrical power? 9 No e. Have there been any extremes in heat or cold? 9 No Note : Form to be completed based on data and documents available to the PWS operator in charge, maintained on file and returned to the Primacy Agency within 
CONCEPT EXAMPLE NO. 5 

Level 2 Assessment Form 

B-26 

Additional Comments: Print name of person completing form: Chris Weaver Date: 02/03/2010 Signature: Reserved for State 

1. Assessment has been successfully completed. Name of State Reviewer: 
B-27 

Example No. 6 – Level 2 Assessment 

UTILITY PROFILE 

Chimney Bluffs Community Church is a transient non-community water system that gets its 

water from a ground water source. It serves a population of about 200 people and takes a routine 

sample every quarter. 

DESCRIPTION OF THE PROBLEM 

The system had two total coliform-positive samples in July 2009 and again in March 2010 

triggering a Level 2 assessment (2 Level 1 assessments within a rolling 12-month period). Since 

the system does not have anyone approved by the State to perform a Level 2 assessment, the 

Operator in Responsible Charge (ORC) identified an assessor approved by the State from the 

State website. 

ASSESSMENT AND CORRECTIVE ACTION 

The system noted three possible sources of contamination: 1) inadequate/improper chlorination 

of an in-line conditioner after replacement of pressure tank and plumbing; 2) need for 

replacement of filters in the reverse osmosis system; and 3) use of a swivel faucet at the 

sampling site. The system suspected the first possible source as the cause of the contamination 

and chlorinated the in-line conditioner in March 2010. The old swivel faucet was also replaced. 

 
B-28 

THIS PAGE INTENTIONALLY LEFT BLANK
CONCEPT EXAMPLE NO. 6 

Level 2 Assessment Form 

B-29 

System Name: Chimney Bluffs Community Church Source Water: Ground Water PWSSystem Type: TNCWS Population Served: 200 PWS Operator in Responsible Charge (ORC): Mary Spelling Phone: 012-345-6789 123 City, State: Chimney Bluffs, AZ 1000County: Jackson Person that collected TC samples if different than ORC: A. Brown, ABC Labs Phone: 123-456-7890 Address, City, State, Zip: 7556 Desert Ave, Tempe, AZ 99999 Date Assessment Completed: 04/06/2010 

Questions 

Reviewed and 

checked? 

(Type “3” if 

completed or 

“N/A”) 

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

1. Have any of the following occurred at relevant facilities prior to the collection of TC samples? a. Were there any operation and maintenance activities that could have introduced total coliforms? 9 Yes 

The pressure tank and plumbing in and around the pump room were recently replaced. System includes an in-line water conditioner. It is unknown if water conditioner was chlorinated or by-passed during the chlorination prior to putting tank and plumbing back in service. 

Watput b

b. Have there been any interruptions in the treatment process? 9 No c. Has the system lost pressure to less than 5 psi? 9 No d. Have there been any vandalism and/or unauthorized access to facilities? 9 No e. Are there any visible indicators of unsanitary conditions observed? 9 No f. 

Have there been any analytical results or any additional samples collected, including source samples which were positive (not for compliance)? 

9 No 

g. 

Have there been any community illness suspected of being waterborne (e.g., Does the community public health official indicate 

that an outbreak has occurred.) 

9 No 

h. Did the water system receive any TCR monitoring violations in the past 12 months? If yes, when. 9 Yes July 2009 i. What was the most recent date on which satisfactory total coliform samples were taken? Date: Dec 2009j. Have there been a fire fighting event, flushing operation, sheared hydrant, etc. 9 No k. Other comments on records and maintenance? None 2. Have there been any recent treatment or operational changes? 
CONCEPT EXAMPLE NO. 6 

Level 2 Assessment Form 

B-30 

Questions 

Reviewed and 

checked? 

(Type “3” if 

completed or 

“N/A”) 

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

a. Have any inactive sources recently been introduced into the system (e.g., auxiliary systems)? 9 No b. Have there been any new sources introduced into the system? 9 No c. Is there evidence of any potential sources of contamination (main breaks, low pressure, high turbidity, loss of disinfection, etc.)? 9 No 3. Evaluate sample site a. What is the condition of the tap? (Provide comments) Fair b. What is the location of the tap? (Provide comments) church rectory c. What is the regular use of the connection? (Provide comments) potable water source for the rectory d. Have there been any plumbing changes or construction? If yes, when and what was the repair or change? 9 No e. Have there been any plumbing breaks or failure? If yes, when? 9 No f. 

List any identified cross connections after the service connection or in premise plumbing. (Provide comments)

In-line water conditioner 

g. Were all of the backflow prevention devices present, operational and maintained? 9 No h. 

Were there any low pressure events or changes in water pressure after the service connection or in the premise plumbing? If yes, when? 

9 No 

i. 

Is there any treatment devices after the service connection or in premise? (Circle response, if applicable)

Point of Entry (POE) Point of Use (POU) 

j. Other comments on sample site? None 4. Sample protocol followed and reviewed a. Flush tap, remove aerator, no swivel, fresh sample bottles, sample storage acceptable 9 Yes Sample site had old swivel faucet. Fau5. Distribution System a. System pressure: Is there evidence that the system experienced low or negative pressure? If yes, when? 9 No b. List any identified cross connections. 9 No c. Pump station: Are there any sanitary defects in the pump station? Are pump(s) operable? 9 No d. Last pump maintenance/service date. (Respond if applicable) Date: N/A Maintenance Performed? 
CONCEPT EXAMPLE NO. 6 

Level 2 Assessment Form 

B-31 

Questions 

Reviewed and 

checked? 

(Type “3” if 

completed or 

“N/A”) 

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

e. 

Air relief valves: Is the valve vault subject to flooding or does the vent terminate below grade? 

9 No 

f. Fire hydrant/blow off: Are any located in an area with a high water table or pits? 9 No g. Is the distribution system secured to prevent unauthorized access? 9 No h. Are the backflow prevention devices at high risk sites present, operational and maintained? 9 No i. Have there been any water main repairs or additions? If yes when, and what was the repair or addition? 9 No j. Have there been any water main breaks? If yes, when? 9 No k. Was there any scheduled flushing of the distribution system? If yes, when? 9 No l. Is there any evidence of intentional contamination in the distribution system? 9 No m. Other comments on the distribution information. None 6. Storage Facilities a. Are the overflow and vents properly screened? N/A b. Is the facility secured to prevent unauthorized access? N/Ac. Does the access opening have the proper gasket and seal tightly? N/Ad. Could the physical condition of tank be a source of contamination? N/Ae. Is the vent turned down and maintaining an approved air gap at the termination point? N/Af. Does the drain/overflow line terminate at a minimum of 12" air gap? N/Ag. If present, is the pressure tank maintaining an appropriate minimum pressure? N/Ah. Has proper O&M been performed? N/Ai. Was there any observed physical deterioration of the tank? N/Aj. Were there any observed leaks? N/Ak. Is there any evidence of intentional contamination at the storage tank? N/Al. Has there been any facility maintenance (i.e. painting/coating)? If yes, when? N/Am. Is facility maintenance occurring per appropriate schedule? N/A
CONCEPT EXAMPLE NO. 6 

Level 2 Assessment Form 

B-32 

Questions 

Reviewed and 

checked? 

(Type “3” if 

completed or 

“N/A”) 

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

n. Does the tank "float" on the distribution system or are there separate inlet and outlet lines? N/Ao. What is the measured chlorine residual (total/free) of the water exiting the storage tank today? Residual N/Ap. Are there any unsealed openings in the storage facility such as access doors, vents or joints? N/Aq. Other comments on the storage system None 7. Treatment Process. (If applicable) a. Treatment devices operational and maintained? 9 No b. Is there any recent installation or repair of treatment equipment? 9 Yes 

The filters were replaced in the reverse osmosis system that feeds the faucets connected to the rectory and the kitchen. 

Filtecontbe re

c. Were there any recent changes in the treatment process? If yes, when, what was the change? 9 No d. 

Were there any interruptions of treatment (lapses in chemical feed, turbidity excursions, disinfection)? If yes which part, when and for how long? 

9 No 

e. What is the free chlorine residual measured immediately downstream from the point of application? Residual: N/Af. Did a review of the filter turbidity profiles reveal any anomalies? N/A g. Were there any failures to meet the C x T calculations? N/Ah. Were the flow rates above the rated capacity? N/Ai. Were there any anomalies on the settled water turbidities? N/Aj. Other comments on the treatment system. None 8. Source – Well a. Is the sanitary seal intact? 9 No b. Is the vent screened? 9 No c. Does the vent and pump to waste terminate in an approved air gap? 9 No d. Are there any unprotected cross connections at the wellhead? 9 No e. 

How is the well used? (Circle if applicable)

 Primary Backup Emergency Not a PWS Not Drinking W

f. How far does the casing extend above grade? Height ____________ Comments: 
CONCEPT EXAMPLE NO. 6 

Level 2 Assessment Form 

B-33 

Questions 

Reviewed and 

checked? 

(Type “3” if 

completed or 

“N/A”) 

Issue(s) 

found? 

(Y/N) 

Issue Description Cor

g. Is the well cap vented? 9 No h. Is there evidence of standing water near the wellhead? 9 No i. Is the wellhead secured to prevent unauthorized access? 9 No j. Have there been any sewer spills, source water spills or other disturbances? 9 No k. Other comments on the well system. (Are there aspects of well construction and operation that would bear on observed positives?) None 9. Source – Spring a. What is the condition of the spring development? N/A b. What is the condition of the spring box? N/Ac. Is the spring secured to prevent unauthorized access? N/Ad. Other comments on the spring system. None 10. Source - Surface Water Supply a. Have there been any sewer spills, source water spills or other disturbances? N/Ab. Have there been any algal blooms? N/Ac. Has source water turnover occurred? N/Ad. Other source water comments None Environmental Events a. Has there been heavy rainfall? 9 No b. Has there been any rapid snow melt or flooding? 9 No c. Have there been changes in available source water (e.g., significant drop in water table, well levels, reservoir capacity, etc.) 9 No d. Have there been any interruptions to electrical power? 9 No e. Have there been any extremes in heat or cold? 9 No Note : Form to be completed based on data and documents available to the PWS operator in charge, maintained on file and returned to the Primacy Agency within Additional Comments: 
CONCEPT EXAMPLE NO. 6 

Level 2 Assessment Form 

B-34 

Print name of person completing form: John Marshall Date: 04/08/2010 Signature: Reserved for State 

1. Assessment has been successfully completed. Name of State Reviewer: 
C-1 

Appendix C 

Common Sanitary Defects and Corrective Actions

Appendix C presents a summary of the causes of total coliform- / E. coli-positive (TC+/EC+) 

results that have been frequently found in the past and the corresponding corrective action(s) that 

systems can take to correct the problem. It is intended to give concise guidance in a look-up 

table format that PWSs can easily refer to in the event that they are triggered to have an 

assessment and perform corrective action. Some of the materials in the following table are 

discussed in more detail in Chapter 4 of this document. 

The list is by no means comprehensive or exhaustive and does not include investigation, 

operation and maintenance, or corrective action guidance particular to each State. Systems 

should be aware of State guidelines and consult with the State as necessary. 

The list of sanitary defects is based on the common causes of TC+/EC+ reported by States and 

PWSs. EPA is interested in hearing from the public on other possible causes of TC+ and 

EC+ they want to see address in this guidance manual. 

 

 
C-2 

THIS PAGE INTENTIONALLY LEFT BLANK
C-3 

Sanitary Defects / 

Cause(s) of TC+ and 

EC+ 

Conditions That May Point to Cause 

of TC+/EC+ Possible Corrective Action(s) For A

Biofilms • Taste and odor complaints 

• Colored or turbid water that takes a 

long time to clear 

• Elevated heterotrophic plate count 

(HPC) bacteria levels 

• Numerous isolates with similar 

genotypic profile 

• Conduct unidirectional flushing to 

remove biofilm and sediments from distribution system. 

• Maintain adequate pressure in 

system to prevent sloughing of biofilm by installing booster pump stations, variable frequency drives, elevated storage facilities, surge relief valves, and surge tanks, and modifying high service pumps. Install automatic pressure monitoring and control. 

• Replace/rehabilitate pipe where 

biofilm sloughing is occurring. 

• Maintain disinfectant residuals in 

the distribution system. 

• Apply temporary disinfection, 

shock chlorination, and/or booster disinfection, in accordance with State guidelines. 

• Manage water age by looping dead 

ends; increasing volume turnover; and/or installing appropriate main sizes, automated flushing devices, or mixing devices. 

• Wat

FouManand Syst

• Wat

FouLimin DLabExp

• Wat

FouConDis

• Wat

FouAffein MSyst

• Cam

“EfSysBacJourIss. 107

Contamination of water during main installation, repair, or rehabilitation 

• Break/repair activities that could 

have allowed entry of contaminants or dislodged accumulated pipe debris into bulk water 

• Pressure loss associated with break 

• Flush system (spot or routine). 

• Apply temporary disinfection, 

shock chlorination, and/or booster disinfection in accordance with State guidelines. 

• AW

for Mai
C-4 

Sanitary Defects / 

Cause(s) of TC+ and 

EC+ 

Conditions That May Point to Cause 

of TC+/EC+ Possible Corrective Action(s) For A

• Low disinfectant residual • Colored or turbid water 

• Review/enhance existing 

procedures for main installation, repair, or rehabilitation procedures. 

• Maintain adequate pressure in the 

system by installing booster pump stations, variable frequency drives, elevated storage facilities, surge relief valves, and surge tanks, and modifying high service pumps. Install automatic pressure monitoring and control. 

Cross-connections • Pressure loss event within a portion 

of the distribution system 

• Total coliform-positive samples 

occur at high elevation and/or low pressure location(s) 

• Presence of a high-risk customer 

for backflow (e.g., industrial user) 

• Eliminate cross-connection. 

• Implement cross-connection 

control and backflow prevention (CCBFP) program. 

• Install backflow prevention 

assemblies and devices. 

• Flush system (spot or routine). • Apply temporary disinfection, 

shock chlorination, and/or booster disinfection in accordance with State guidelines. 

• Maintain adequate pressure in 

system to prevent backflow and backsiphonage by installing booster pump stations, variable frequency drives, elevated storage facilities, surge relief valves, and surge tanks, and modifying high service pumps. Install automatic pressure monitoring and control. 

• Cro

Man002

Errors in the sampling protocol (i.e., proper 

• Changes in sampler or protocol • Review current protocol and if 

inadequate, identify alternate 

• Wat

Fou
C-5 

Sanitary Defects / 

Cause(s) of TC+ and 

EC+ 

Conditions That May Point to Cause 

of TC+/EC+ Possible Corrective Action(s) For A

sampling protocols were not followed – e.g., tap was not flushed, aerator was not removed, etc.) 

protocol. 

• Enhance training on site 

preparation, flushing protocols, and sanitary sample collection and transport procedures. 

• Sanitize sample coolers and ice 

packs. Ensure that samples are shipped properly and securely (e.g., bottles do not tip or become contaminated during transport). 

ColLocCom200

• Inte

for Opehttpom/

Inadequacies of the sample site (e.g., unsanitary conditions, leaks and breaches, unprotected access, improper construction, improper location) 

• Changes in sampling site use • Presence of unsanitary conditions 

at the sampling site 

• Develop a sample siting plan that is 

representative of the water quality in the distribution system. 

• Install dedicated sampling taps. • Correct leaks or other site 

deficiencies and breaches. 

• Sanitize or replace sampling site. 

• Wat

FouColLocCom200

• Inte

for Opehttpom/

Inadequate disinfectant residual levels in the distribution system 

• Variable raw and/or treated water 

quality conditions 

• Inadequate disinfectant at entry 

point 

• Inadequate disinfectant at booster 

stations 

• Interruptions in disinfection 

processes 

• Increases in temperature that lead 

to accelerated disinfectant decay 

• Apply temporary disinfection, 

shock chlorination, and/or booster disinfection in accordance with State guidelines. 

• Manage water age by looping dead 

ends; increasing volume turnover; and/or installing appropriate main sizes, automated flushing devices, or mixing devices. 

• Install/upgrade on-line water 

• AW

for OpeMan
C-6 

Sanitary Defects / 

Cause(s) of TC+ and 

EC+ 

Conditions That May Point to Cause 

of TC+/EC+ Possible Corrective Action(s) For A

 quality monitoring and control. 

• Flush system (spot or routine). 

Intrusion through pipe leaks, pipeline fracture cracks, leaking joints, submerged air-vacuum/ air-release valves, and deteriorating seals 

• Pressure loss or reduction in a 

portion of the distribution system 

• Presence of leaks, cracks and other 

entry points 

• High groundwater table and/or 

presence of sewers near the susceptible water main 

• Numerous isolates with unique 

genotypic profile 

• Repair/replace leaky component. 

• Maintain adequate pressure in 

system by installing booster pump stations, variable frequency drives, elevated storage facilities, surge relief valves, and surge tanks, and modifying high service pumps. Install automatic pressure monitoring and control. 

• Wat

Fouand TraDis

Pressure loss (can result from events such as flushing, main breaks, power outages, fires, or improper operations and management (O&M) practices) 

• Recent maintenance activities, 

main breaks, power outages, fires 

• Turbidity increase or fluctuations 

• Flush distribution system (spot or 

routine). 

• Apply temporary disinfection, 

shock chlorination, and/or booster disinfection in accordance with State guidelines. 

• Improve O&M practices. • Maintain adequate pressure by 

installing booster pump stations, variable frequency drives, elevated storage facilities, surge relief valves, and surge tanks, and modifying high service pumps. 

• Install automatic pressure 

monitoring and control. 

• AW

for Mai

• AW

for OpeMan

Sediment build-up in storage tank or reservoir 

• Increased disinfectant demands • Increase in turbidity, particularly in 

water samples collected when tank is draining 

• Elevated HPC in samples from tank 

or reservoir 

• Low disinfectant residual in 

• Drain and flush tank or reservoir. 

• Shock chlorination of tank or 

reservoir in accordance with State guidelines. 

• AW

(DisStor
C-7 

Sanitary Defects / 

Cause(s) of TC+ and 

EC+ 

Conditions That May Point to Cause 

of TC+/EC+ Possible Corrective Action(s) For A

samples from tank or reservoir 

Storage tank physical deficiencies like holes, inadequate screening, etc. (can allow entry of birds, animals, insects, and other vectors that can fecally contaminate the water) 

• Presence of physical deficiencies • Recent work on or near the tank 

• Recent vandalism, storm events, or 

other events that could impact tank integrity 

• Repair broken parts of storage tank 

like the vent and hatch. 

• Repair / install screens. • Install / improve security measures. 

• AW

(DisStor

Contamination during flushing/firefighting activities 

• Turbidity increase or fluctuations • Color increase or fluctuations 

• Pressure fluctuations 

• Ensure unidirectional flushing 

approach is used for flushing program and that water quality objectives (i.e., chlorine, turbidity, and iron) are met prior to terminating flushing. 

• Wat

FouImpOptDisPro

• Wat

Fouof WDis

• Wat

Fouof DWatPlan

Treatment breakthrough • Variable raw and/or treated water 

quality conditions 

• Inadequate disinfectant at entry 

point 

• Elevated HPC bacteria levels occur 

throughout the distribution system 

• Increase disinfectant residual. 

Apply temporary disinfection, shock chlorination, and/or booster disinfection in accordance with State guidelines. 

• Flush system (spot or routine). • Assess performance of treatment 

processes and remedy cause of coliform breakthrough (e.g., 

• Sma

Safe Reghttper/
C-8 

Sanitary Defects / 

Cause(s) of TC+ and 

EC+ 

Conditions That May Point to Cause 

of TC+/EC+ Possible Corrective Action(s) For A

replace filter, decrease particle loading, etc.). 

Vandalism and/or unauthorized access to facilities 

• Recent work or other events at a 

distribution system facility 

• Presence of broken or disabled 

security equipment 

• Flush system (spot or routine). 

• Install / improve security measures 

(e.g., install a fence, lock buildings, install alarms and cameras) 

• Develop and implement an 

operations plan. 

• Develop standard operating 

procedures (SOPs). 

• Develop emergency response plan. 

• AW

for OpeMan

• Wat

FouSystWat
D-1 

Appendix D 

Industry Standards for Operating a Public Water System 

The American Water Works Association (AWWA) has developed standards based on the 

collective knowledge of its membership. The information contained in these standards has been 

collected and improved over many years and has gone through rigorous review and development. 

AWWA Standards are typically minimum best practices and help to ensure that a product (e.g., 

pipes, fittings, meters, etc.) or a process (e.g., main flushing, main installation, etc.) described in 

a standard will provide satisfactory service. 

Although not a complete list, the following AWWA Standards may be useful as a reference 

when implementing the corrective action(s) discussed in the RTCR Assessments and Corrective 

Actions Guidance Manual and its appendices. 
D-2 

THIS PAGE INTENTIONALLY LEFT BLANK

 
D-3 

Standard Number Topic 

AWWA A100 Water Wells 

AWWA B300 Hypochlorites 

AWWA B301 Liquid Chlorine 

AWWA C104/A21.4 Cement-Mortar Lining for Ductile-Iron Pipe and Fittings for Water 

AWWA C110/A21.10 Ductile-Iron and Gray-Iron Fittings for Water 

AWWA C111/A21.11 Rubber-Gasket Joints for Ductile-Iron Pressure Pipe and Fittings 

AWWA C115/A21.15 

Flanged Ductile-Iron Pipe with Ductile-Iron or Gray-Iron Threaded 

Flanges 

AWWA C116/A21.16 

Protective Fusion-Bonded Epoxy Coatings for the Interior and Exterior 

Surfaces of Ductile-Iron and Gray-Iron Fittings for Water Supply 

Service 

AWWA C150/A21.50 Thickness Design of Ductile-Iron Pipe-Erratum: 02/2003 

AWWA C151/A21.51 Ductile-Iron Pipe, Centrifugally Cast, for Water- Erratum 

AWWA C153/A21.53 Ductile-Iron Compact Fittings, for Water Service 

AWWA C200 Steel Water Pipe - 6 in. (150 mm) and Larger 

AWWA C203 

Coal-Tar Protective Coatings and Linings for Steel Water Pipelines - 

Enamel and Tape - Hot Applied 

AWWA C205 

Cement-Mortar Protective Lining and Coating for Steel Water Pipe - 4 

in. (100 mm) and Larger - Shop Applied 

AWWA C206 Field Welding of Steel Water Pipe 

AWWA C207 

Steel Pipe Flanges for Waterworks Service - Sizes 4 in. Through 144 in. 

(100 mm Through 3,600 mm) 

AWWA C208 Dimensions for Fabricated Steel Water Pipe Fittings 

AWWA C209 

Cold-Applied Tape Coatings for the Exterior of Special Sections, 

Connections, and Fittings for Steel Water Pipelines 

AWWA C210 

Liquid-Epoxy Coating Systems for the Interior and Exterior of Steel 

Water Pipelines 

AWWA C213 

Fusion-Bonded Epoxy Coating for the Interior and Exterior of Steel 

Water Pipelines 

AWWA C214 Tape Coating Systems for the Exterior of Steel Water Pipelines 

AWWA C215 Extruded Polyolefin Coatings for the Exterior of Steel Water Pipelines 

AWWA C216 

Heat-Shrinkable Cross-Linked Polyolefin Coatings for the Exterior of 

Special Sections, Connections, and Fittings for Steel Water Pipelines 

AWWA C217 

Petrolatum and Petroleum Wax Tape Coatings for the Exterior of 

Connections and Fittings for Steel Water Pipelines 

AWWA C218 

Coating the Exterior of Aboveground Steel Water Pipelines and 

Fittings-Third Edition 

AWWA C222 

Polyurethane Coatings for the Interior and Exterior of Steel Water Pipe 

and Fittings-First Edition 

AWWA C224 

Two-Layer Nylon-11-Based Polyamide Coating System for the Interior 

and Exterior of Steel Water Pipe, Connecctions, Fittings, and Special 

Sections 
D-4 

Standard Number Topic 

AWWA C225 

Fused Polyolefin Coating systems for the Exterior of Steel Water 

Pipelines-First Edition 

AWWA C300 Reinforced Concrete Pressure Pipe, Steel-Cylinder Type 

AWWA C301 

Prestressed Concrete Pressure Pipe, Steel-Cylinder Type-Erratum - 

January 2000 

AWWA C302 Reinforced Concrete Pressure Pipe, Noncylinder Type 

AWWA C303 Concrete Pressure Pipe, Bar-Wrapped, Steel-Cylinder Type 

AWWA C304 Design of Prestressed Concrete Cylinder Pipe 

AWWA C400 

Asbestos-Cement Pressure Pipe, 4 in. Through 16 in. (100 mm Through 

400 mm), for Water Distribution Systems 

AWWA C401 

The Selection of Asbestos-Cement Pressure Pipe, 4 in. Through 16 

in.(100 mm Through 400 mm), for Water Distribution Systems 

AWWA C402 

Asbestos-Cement Transmission Pipe, 18 in. Through 42 in. (450 mm 

Through 1,050 mm), for Water Supply Service 

AWWA C403 

Selection of Asbestos-Cement Transmission Pipe, Sizes 18 in. Through 

42 in. (450 mm Through 1,050 mm), for Water Supply Service 

AWWA C500 Metal-Seated Gate Valves for Water Supply Service 

AWWA C502 Dry-Barrel Fire Hydrants 

AWWA C503 Wet-Barrel Fire Hydrants 

AWWA C508 

Swing-Check Valves for Waterworks Service, 2-in. Through 24-in. (50- 

mm Through 600-mm) NPS 

AWWA C509 Resilient-Seated Gate Valves for Water Supply Service 

AWWA C512 

Air Release, Air/ Vacuum, and Combination Air Valves for Waterworks 

Service 

AWWA C515 

Reduced-Wall, Resilient-Seated Gate Valves for Water Supply ServiceSecond Edition 

AWWA C600 Installation of Ductile-Iron Water Mains and Their Appurtenances 

AWWA C602 

Cement-Mortar Lining of Water Pipelines in Place - 4 in. (100 mm) and 

Larger 

AWWA C605 

Underground Installation of Polyvinyl Chloride (PVC) Pressure Pipe 

and Fittings for Water-First Edition 

AWWA C606 Grooved and Shouldered Joints 

AWWA C651 Disinfecting Water Mains 

AWWA C652 Disinfection of Water-Storage Facilities 

AWWA C653 Disinfection of Water Treatment Plants 

AWWA C654 Disinfection of Wells 

AWWA C700 Cold-Water Meters - Displacement Type, Bronze Main Case 

AWWA C701 Cold-Water Meters - Turbine Type, for Customer Service 

AWWA C702 Cold-Water Meters - Compound Type 

AWWA C703 Cold-Water Meters - Fire Service Type 

AWWA C704 Propeller-Type Meters for Waterworks Applications 
D-5 

Standard Number Topic 

AWWA C706 Direct-Reading, Remote-Registration Systems for Cold-Water Meters 

AWWA C707 Encoder-Type Remote-Registration Systems for Cold-Water Meters 

AWWA C708 Cold-Water Meters - Multijet Type 

AWWA C710 Cold-Water Meters - Displacement Type, Plastic Main Case 

AWWA C712 Cold-Water Meters - Singlejet Type-First Edition 

AWWA C713 Cold-Water Meters Fluidic-Oscillator Type-First Edition 

AWWA C800 Underground Service Line Valves and Fittings 

AWWA C900 

Polyvinyl Chloride (PVC) Pressure Pipe and Fabricated Fittings, 4 in. 

Through 12 in.(100 mm Through 300 mm), for Water Distribution 

AWWA C901 

Polyethylene (PE) Pressure Pipe and Tubing, 1/2 in. (13 mm) Through 3 

in. (76 mm), for Water Service 

AWWA C903 

Polyethylene-Aluminum-Polyethylene & Cross-linked PolyethyleneAluminum-Cross-linked Polyethylene Composite Pressure Pipes, 1/2 In. 

(12 mm) Through 2 In. (50 mm), for Water Service 

AWWA C905 

Polyvinyl Chloride (PVC) Pressure Pipe and Fabricated Fittings, 14 

Inches Through 48 Inches (350mm Through 1,200mm), for Water 

Transmission and Distribution 

AWWA C906 

Polyethylene (PE) Pressure Pipe and Fittings, 4 in. (100 mm) Through 

63 in. (1,575 mm), for Water Distribution and Transmission 

AWWA C907 

Injection-Molded Polyvinyl Chloride (PVC) Pressure Fittings, 4 In. 

Through 12 In. (100 mm Through 300 mm), for Water Distribution 

AWWA C909 

Molecularly Oriented Polyvinyl Chloride (PVCO) Pressure Pipe, 4 in. 

Through 12 in. (100 mm Through 600 mm), for Water Distribution 

AWWA C950 Fiberglass Pressure Pipe 

AWWA D100 Welded Steel Tanks for Water Storage 

AWWA D102 Coating Steel Water-Storage Tanks 

AWWA D103 Factory-Coated Bolted Steel Tanks for Water Storage 

AWWA D104 

Automatically Controlled, Impressed-Current Cathodic Protection for 

the Interior of Steel Water Tanks 

AWWA D110 Wire- and Strand-Wound, Circular, Prestressed Concrete Water Tanks 

AWWA D115 

Circular Prestressed Concrete Water Tanks with Circumferential 

Tendons-First Edition 

AWWA D130 Flexible-Membrane Materials for Potable Water Applications 

AWWA G100 Water Treatment Plant Operation and Management-First Edition 

AWWA G200 Distribution Systems Operation and Management