EPA United States

Environmental

Protection

Agency

Office of Water

(4607)

EPA 815-R-01-025

October 2001

SMALL SYSTEM REQUIREMENTS

FOR THE STAGE 1 DISINFECTANTS

AND DISINFECTION BYPRODUCTS 

RULE

SMALL ENTITY COMPLIANCE GUIDE
NOTICE

This guide was prepared pursuant to section 212 of the Small Business Regulatory

Enforcement Fairness Act of 1996 ("SBREFA"), Pub. L. 104-121. THIS DOCUMENT IS

NOT INTENDED, NOR CAN IT BE RELIED UPON, TO CREATE ANY RIGHTS

ENFORCEABLE BY ANY PARTY IN LITIGATION WITH THE UNITED STATES. The

statements in this document are intended solely as guidance to aid you in complying with the

Stage 1 Disinfectants/Disinfection Byproducts (Stage 1 DBP) Rule (63 FR 69390, December

16, 1998). While the guidance contained in this document may assist you, the public, and

State and federal regulators in applying regulatory requirements, the guidance is not a

substitute for those legal requirements; nor is it a regulation itself. Thus it does not impose

any legally-binding requirements on any party, including EPA, States, or the regulated

community. In any civil or administrative action against a small business, small government

or small non-profit organization for a violation of the Stage 1 DBP Rule, the content of this

guide may be considered as evidence of the reasonableness or appropriateness of proposed

fines, penalties or damages. EPA may decide to revise this guide without public notice to

reflect changes in EPA's approach to implementing the Stage 1 DBP Rule or to clarify and

update the text. To determine whether EPA has revised this guide and/or obtain copies,

contact the Safe Drinking Water Hotline at 1-800-426-4791.
i

SMALL SYSTEM REQUIREMENTS FOR THE

STAGE 1 DISINFECTANTS AND DISINFECTION

BYPRODUCTS RULE

TABLE OF CONTENTS

Page

Abbreviations used in this document

I. Introduction

II. What Does This Regulation Require?

III. Step-by-Step Procedures for Compliance With This Rule

IV. Questions and Answers About the Stage 1 DBPR

V. The Compliance Assurance Process

APPENDICES

A. Glossary of terms used in this guide

B. Where to obtain more information

C. Questionnaire - How useful was this guide?

D. What to do if you use chlorine dioxide

E. What to do if you use ozone

F. What to do if you are required to do enhanced coagulation or

enhanced softening

G. Stage 1 Disinfectants and Disinfection Byproducts Rule: A Quick

Reference Guide

 ii

 I-1

 II-1

 III-1

 IV-1

 V-1

 A-1

 B-1

 C-1

 D-1

 E-1

 F-1

 G-1
ii

Abbreviations used in this document

BAT: Best available technology

CDC: Centers for Disease Control

CWS: Community water system

DBP: Disinfection byproducts

DBPP: Disinfection byproduct precursor

DBPR: Disinfectants and Disinfection Byproducts Rule

DOC: Dissolved organic carbon

DWSRF: Drinking Water State Revolving Fund

EPA: United States Environmental Protection Agency

ESWTR: Enhanced Surface Water Treatment Rule

FACA: Federal Advisory Committee Act

FR: Federal Register

GAC10: Granular activated carbon with ten minute empty bed contact time and 180 day

reactivation frequency 

HAA5: Haloacetic acids (five)

ICR: Information Collection Rule

IESWTR: Interim Enhanced Surface Water Treatment Rule

MCL: Maximum contaminant level 

MCLG: Maximum contaminant level goal

M-DBP: Microbial and Disinfectants/Disinfection Byproducts

mg/L: Milligrams per liter

MRDL: Maximum residual disinfectant level

MRDLG: Maximum residual disinfectant level goal

NTNCWS: Nontransient noncommunity water system

PWS: Public water system

Reg-Neg: Regulatory Negotiation

RUS: Rural Utilities Service

SBREFA: Small Business Regulatory Enforcement Fairness Act 

SDWA: Safe Drinking Water Act, or the "Act," as amended in l986 and 1996

SUVA: Specific ultraviolet absorbance

SWTR: Surface Water Treatment Rule

TOC: Total organic carbon

TTHM: Total trihalomethanes

TNCWS: Transient noncommunity water systems

UV: Ultraviolet light
I-1

I. INTRODUCTION

This document is published by the Environmental Protection Agency (EPA) as our official

compliance guide for small public water systems, as required by the Small Business Regulatory

Enforcement Fairness Act of 1996. Before you begin using the guide, you should know that the

information in this guide was compiled and published on October 31, 2001. EPA is continually

improving and upgrading its rules, policies, compliance programs, and outreach efforts. You can

determine whether EPA has revised or supplemented the information in this guide by calling the

Safe Drinking Water Hotline at 800-426-4791.

A. Who should use this guide?

This guide is intended for use by small public water systems - those serving fewer than 10,000

people. It is specifically intended for small community water systems (CWS) and nontransient

noncommunity water systems (NTNCWS) that add a chemical disinfectant or oxidant, such as

chlorine, chloramines, ozone, or chlorine dioxide, as part of the drinking water treatment process. 

Finally, there are a limited number of requirements that apply to transient noncommunity water

systems that add chlorine dioxide as part of their drinking water treatment process.

B. What does the guide cover?

This guide contains a general introduction to the background, development, and benefits of this

rule. Section II contains background information on the development of this rule, along with a

general explanation of the rule’s requirements and a brief discussion of other rules that EPA is

developing that will help address pathogen and chemical byproduct risks that are not addressed in

this rule. Section III contains a detailed explanation of the regulatory requirements of the Stage 1

Disinfectants and Disinfection Byproducts Rule (Stage 1 DBPR) for systems serving fewer than

10,000 people, including sections specifically addressing requirements for systems based on

source water type and disinfectant or treatment used. Section IV includes questions and answers

about provisions in the rule. Section V is an overview of EPA’s compliance assurance process.

Appendix A contains a glossary of terms used in the rule and in this guide. Appendix B contains

instructions on how to order the technical guidance manuals and other publications that EPA has

developed to support implementation of and compliance with this rule. Appendix C is a

questionaire on how to make future versions of this guide more useful. Appendices D, E, and F

contained detailed explanations of requirements for technologies that few small systems use

(chlorine dioxide, ozone, and conventional filtration treatment, respectively), but are required to

comply with if used.

C. How do I use the Guide?

We suggest that you read through the entire guide. Refer to Appendix A if you find a term that
I-2

you are not familiar with. After looking at the entire guide, go back to Section III to begin to

identify specific requirements that apply to your system.

D. How do I obtain a complete copy of the rule?

The Stage 1 Disinfectants/Disinfection Byproducts Rule was published in the Federal Register on

December 16, 1998 (63 FR 69390). You may call the Safe Drinking Water Hotline at 800-426-

4791 to request a copy. You may also download a copy at

http://www.epa.gov/safewater/mdbp/dbpfr.html. Appendix B has further information on

ordering the guidance manuals that support this rule or downloading them from the Internet.The

Code of Federal Regulation will also provide needed information, refer to the following sections

in 40 CFR Ch. 1:

Title Section number

Maximum contaminant level goals for

disinfection byproducts.

141.53

Maximum residual disinfectant level goals for

disinfectants.

141.54

Maximum contaminant levels for disinfection

byproducts.

141.64

Maximum residual disinfectant levels. 141.65

General requirements. 141.130

Analytical requirements. 141.131

Compliance requirements. 141.132

Reporting and recordkeeping requirements. 141.134

Treatment technique for control of

disinfection byproduct (DBP) precursors.

141.135

The Code of Federal Regulation can be accessed on the internet at

http://www.gpo.gov/nara/cfr/index.html. 
II-1

II WHAT DOES THIS REGULATION REQUIRE?

A. What human health issues does this rule address and why is it important?

In 1990, EPA’s Science Advisory Board, an independent panel of experts established by

Congress, cited drinking water contamination as one of the most important environmental risks

and indicated that disease-causing microbial contaminants (i.e., bacteria, protozoa, and viruses) -

also known as pathogens - are probably the greatest remaining health-risk management

challenge for drinking water suppliers. Data from the Centers for Disease Control (CDC) confirm

this concern and indicate that between 1980 and 1994, 379 waterborne disease outbreaks were

reported, with over 500,000 cases of disease. During this period, a number of agents were

implicated as the cause, including protozoa, viruses, bacteria, and several chemicals. Most of the

cases (but not most of the outbreaks) were associated with surface water, including a 1993

outbreak of 400,000 cases of cryptosporidiosis (caused by the protozoan Cryptosporidium) in

Milwaukee.

One of the key regulations EPA has developed to date to counter pathogens in drinking water is

the 1989 Surface Water Treatment Rule (SWTR). Among its provisions, the rule requires that a

surface water system have sufficient treatment to reduce the source water concentration of

Giardia lamblia and viruses by at least 99.9 percent (3 log) and 99.99 percent (4 log),

respectively. The goal of the SWTR is to reduce risk to less than one infection per year per

10,000 people. However, the SWTR’s limitations include: 1) some systems have high pathogen

concentrations that, when reduced by the levels required under the rule, still may not meet this

health goal, and 2) the rule does not specifically control for the protozoan Cryptosporidium.

In addition to these microbial issues, there is another potentially complicating public health

concern. Many water systems treat their water with a chemical disinfectant in order to inactivate

pathogens. The public health benefits of common disinfection practices are significant and wellrecognized; however, disinfection poses risks of its own. While disinfectants are effective in

controlling many harmful microorganisms, they react with organic and inorganic matter (known

as disinfection byproduct precursors—DBPPs) in the water and form DBPs, some of which pose

health risks at certain levels. Since the discovery of chlorination byproducts in drinking water in

1974, many toxicological studies have shown some DBPs to be carcinogenic (cancer-causing)

and/or to cause reproductive or developmental effects in laboratory animals. Additionally,

exposure to high levels of disinfectants over long periods of time may cause health problems,

including damage to blood and kidneys. While many of these studies have been conducted at

high doses, the weight-of-evidence indicates that disinfectants and DBPs present a potential

public health problem that must be addressed. One of the most complex questions facing water

supply professionals is how to reduce risks from disinfectants and DBPs while providing

increased protection against microbial contaminants. Much of the population is exposed to these

risks; therefore, a substantial concern exists.

Health risks associated with some DBPs are currently addressed by the regulation of total
II-2

trihalomethanes (TTHM) at public water systems (PWSs) serving 10,000 or more people. EPA,

however, believes that the Stage 1 DBPR will significantly decrease the risks posed by DBPs and

disinfectants. The Stage 1 DBPR will broaden public health protection by 1) reducing the TTHM

allowable level, 2) regulating disinfectants and additional DBPs, 3) reducing risks from

unregulated DBPs, and 4) extending coverage to all systems, including small PWSs not currently

regulated for TTHM or other DBPs.

The new rules are a product of six years of collaboration among water suppliers; environmental,

consumer, and public health groups; local elected officials; and local, State, and Federal

regulatory and public health agencies. To address the complex issues associated with regulating

pathogens, EPA first launched a rule-making process in 1992 and convened a Regulatory

Negotiation (RegNeg) Advisory Committee under the Federal Advisory Committees Act

(FACA), representing a range of stakeholders affected by possible regulation. The RegNeg

Committee met over a period of 10 months and arrived at a consensus proposal for taking

incremental steps toward addressing both DBPs and microbial pathogens. The 1992 consensusbuilding process resulted in the three following regulatory proposals—

- A staged approach to regulation of DBPs (referred to as the Stage 1 and Stage 2 DBPRs)

incorporating maximum contaminant levels (MCLs), maximum residual disinfectant

levels (MRDLs), and treatment technique requirements;

- A companion Enhanced Surface Water Treatment Rule (ESWTR), to be finalized at

different times for large (those serving at least 10,000 people) and small systems,

designed to improve control of pathogens and prevent inadvertent reductions in microbial

safety as a result of DBP control efforts; and,

- An Information Collection Rule (ICR) to collect information necessary to reduce many

key uncertainties (about issues such as health effects and formation and occurrence of

DBPs) prior to subsequent negotiations for the Stage 2 DBPR.

Congress amended the Safe Drinking Water Act (SDWA) in 1996 and affirmed the strategy

developed by the RegNeg Committee. Congress also established a series of new statutory

deadlines for the rules.

In 1997, a similar FACA process was implemented with the Microbial-Disinfectants/Disinfection

Byproducts (M-DBP) Advisory Committee. The M-DBP Committee convened to collect, share,

and analyze new information available since the rules were proposed in 1994 and review

previous assumptions made during the RegNeg process, as well as build consensus on the

regulatory implications of this new information. The Stage 1 DBPR and the IESWTR are the

result of the FACA process.

B. Summary of the new regulation
II-3

This section contains a summary of the major requirements of this rule, but does not include

specific monitoring requirements or how to calculate compliance. Compliance for some

regulated compounds is based on a running annual average, while compliance for others is based

on shorter periods. See Section III for details.

MCLGs and MCLs for disinfection byproducts

The Stage 1 DBPR sets maximum contaminant level goals (MCLGs) for some of the regulated

DBPs, a more stringent maximum contaminant level (MCL) for total trihalomethanes (TTHM),

and new MCLs for haloacetic acids (five) (HAA5), bromate, and chlorite. MCLGs are set at

concentrations at which no known or anticipated adverse health effects are expected to occur,

with an adequate margin of safety. They are non-enforceable public health goals. MCLs are

enforceable contaminant standards set as close as is feasible to MCLGs. These MCLs, along

with the maximum residual disinfectant levels (MRDLs) and the treatment technique explained

in the following paragraphs, will help reduce exposure to DBPs and disinfectants and their

associated health effects.

Disinfection Byproduct MCLG (mg/L) MCL (mg/L)

Total Trihalomethanes (TTH M),

consisting of:

ND 0.080

Chloroform ND ND

Bromodichloromethane 0 ND

Bromoform 0 ND

Dibromochloromethane 0.06 ND

Five Haloacetic Acids (HAA5),

consisting of:

ND 0.060

Monochloroacetic Acid ND ND

Dichloroacetic Acid 0 ND

Trichloroacetic Acid 0.3 ND

Monobromoacetic Acid ND ND

Dibromoacetic Acid ND ND

Chlorite 0.8 1.0

Bromate 0 0.010

ND - not determined

MRDLGs and MRDLs for disinfectant residuals
II-4

To protect against potential health risks caused by high levels of residual disinfectants, the Stage

1 DBPR sets the following maximum residual disinfectant level goals (MRDLGs) and maximum

residual disinfectant levels (MRDLs). Like MCLGs and MCLs, respectively, MRDLGs are nonenforceable, while MRDLs are enforceable and are set as close as is feasible to MRDLGs.

Disinfectant MRDLG (mg/L) MRDL (mg/L)

Chlorine 4 4.0

Chloramines 4 4.0

Chlorine Dioxide 0.8 0.8

Treatment technique for disinfection byproduct precursors

The rule includes an enforceable treatment technique that applies to subpart H systems (systems

that use surface water or ground water under the direct influence of surface water—GWUDI—as

a source) using conventional filtration treatment. There are very few small systems that will have

to meet this requirement, since it does not apply if you use only ground water or if you treat

surface water using a filtration technology other than conventional filtration treatment. The

treatment technique was established because disinfectants can react with organic and inorganic

disinfection byproduct precursors (DBPPs) to form both regulated and non-regulated DBPs. The

treatment technique applies to subpart H systems with conventional filtration treatment because

the Advisory Committee determined that such systems generally had higher levels of disinfection

byproduct precursors and conventional filtration treatment was able to lower those levels (and

consequently DBP levels) economically. The treatment technique requirements in the rule are

designed to provide public health protection by reducing the production of both regulated and

unregulated DBPs. Compliance with the treatment technique can be achieved by removing

specified percentages of total organic carbon (TOC) using enhanced coagulation or enhanced

softening. Alternatively, systems may comply by showing they meet alternative compliance

criteria that indicate additional removal of DBPPs by that particular system is unnecessary or

impractical. For example, there is an alternative compliance criterion for systems which have a

low level of TOC in their source or treated water. The treatment technique and these alternatives

are discussed in Appendix F.

Best available technology (BAT)

EPA has specified the Best Available Technology (BAT) for each MCL and MRDL established

in the rule. These technologies and methods are believed to be effective in controlling chemicals

in drinking water while remaining economically feasible for PWSs to employ. PWSs must use

the specified BAT if they wish to qualify for variances. Otherwise, systems are not required to

install BAT and may use any technology to achieve compliance.
II-5

Chemical Best Available Technology

DBPs

TTHM and HAA5 Enhanced coagulation or granular activated carbon (GAC 10), with

chlorine as the primary and residual disinfectant

Chlorite Control of treatment processes to reduce disinfectant demand and control

of disinfection treatment processes to reduce disinfectant levels

Bromate Control of ozone treatment process to reduce production of bromate

Disinfectants

Chlorine, chloramine, 

and chlorine dioxide

Control of treatment processes to reduce disinfectant demand and control

of disinfection treatment processes to reduce disinfectant levels

Public water system recordkeeping and reporting requirements

For each disinfectant, contaminant, contaminant group, and treatment technique, EPA has

developed routine compliance monitoring schemes to be protective of acute and chronic health

concerns. The compliance monitoring requirements vary by the size and type of system, the

treatment employed, and the disinfectant used. In many cases, systems may reduce monitoring to

a frequency and location that will provide a worst-case sample after establishing a baseline that

demonstrates that violations are unlikely.

Systems required to sample quarterly or more frequently must report to the State within 10 days

after the end of each quarter in which the samples were collected. Those required to sample less

frequently than quarterly must report to the State within 10 days after the end of each monitoring

period in which samples were collected. Systems that are required to conduct additional

monitoring because of the disinfectant used (e.g., chlorine dioxide) are subject to additional

reporting requirements if certain concentrations are exceeded. Specifics concerning monitoring

and reporting are in Section III and Appendices D, E, and F.

Laboratory methods and certification

The rule specifies analytical methods for measuring each relevant water quality parameter,

disinfectant, contaminant, and DBPP. Consistent with current regulations, only certified

laboratories can analyze samples for compliance with the MCLs. For disinfectants and other

specified parameters that EPA believes can be adequately measured by other than certified

laboratories, and for which there is good reason to allow on-site analysis (e.g., for samples that

may deteriorate before reaching a certified laboratory), EPA requires that analyses be conducted

by a party approved by the State.

Benefits of the Rule

The Stage 1 DBPR is expected to reduce the risks associated with exposure to disinfectants and

DBPs. The MCLs will reduce exposure to specific DBPs from the use of ozone (byproduct:

bromate), chlorine dioxide (byproduct: chlorite), and chlorine (byproducts: TTHM and five

haloacetic acids - HAA5). In addition, the implementation of a treatment technique (enhanced
II-6

coagulation/ enhanced softening) will reduce overall exposure to the broad range of nonspecified DBPs. In the Regulatory Impact Analysis for the Stage 1 DBPR, EPA estimated that the

rule will result in a national annual average reduction in TTHM levels of 24 percent. As many as

140 million people will have increased protection from DPBs and their potential health risks,

including bladder cancer and adverse developmental and reproductive health effects. 

C. Compliance timetable

The 1979 Total Trihalomethane (TTHM) Rule requirements apply only to systems serving

10,000 or more people. The Stage 1 Disinfectants and Disinfection Byproducts Rule (DBPR)

covers a larger number of PWSs, applying to all community water systems (CWSs) and

nontransient noncommunity water systems (NTNCWSs) that add a chemical disinfectant for

either primary or residual treatment or as an oxidant. In addition, certain requirements apply to

transient noncommunity water systems (TNCWSs) that use chlorine dioxide.

Subpart H systems (systems that use surface water or ground water under the direct influence of

surface water—GWUDI—as a source) serving 10,000 or more people must comply with the

requirements of the Stage 1 DBPR no later than January 1, 2002. Subpart H systems that serve

fewer than 10,000 people, and all affected ground water systems, must comply with the

requirements no later than January 1, 2004. The timetable for the Stage 1 DBPR is presented in

Table 1.
II-7

Table 1: Timetable for the Stage 1 DBPR Requirements for Systems serving fewer

than 10,000 People

Date Rule Requirement1

December 16, 1998 Rule published in Federal Register.

February 16, 1999 Methods specified in §141.131 for analyzing disinfection byproducts, disinfection

residuals, and DBP precursors effective.

January 2003 Subpart H systems using conventional filtration treatment may begin optional

monitoring to determine Step 1 TOC removals before the compliance date.

January 1, 2004 - Requirements effective for systems serving fewer than 10,000 people.

 - Monitoring requirem ents

 - Reporting a nd record keeping re quiremen ts

 - Compliance

 - MCLs fo r TTH M, HA A5, bromate 2, and chlorite 3

 - MRDLs for chlorine, chloramines, and chlorine dioxide3

 - Treatment technique for control of DBP precursors4

- Subpart H and groun d water T NCW Ss that use chlo rine dioxid e must com ply with

requirements for chlorine dioxide.

June 30, 2005 Systems that made a clea r and irrevo cable financ ial commitm ent before th e applicab le

compliance date to install technologies that limit TTHM and H AA5 to 0.040 mg/L and

0.030 mg/L, respectively, must have these technologies installed and operating.

NOTES:

1. Compliance monitoring must begin when noted. The first compliance calculations are made based on whether

compliance is monthly or more frequently (such as chlorine dioxide and chlorite) or as a running annual average

(such as TTHM and bromate). Systems are not required to use data collected prior to the date noted in this table for

compliance determ inations.

2. Only for systems that use ozone

3. Only for systems that use chlorine dioxide

4. Only for subpart H systems that use conventional filtration treatment

D. How does this rule relate to other federal, State, and local requirements?

The Stage 1 DBPR and the IESWTR were published simultaneously to address the inherent

tradeoffs between protection from microbial contamination and the potential health effects from

disinfectants and their byproducts. These rules are the first in a series of rules that will continue

to address the public health concerns associated with microbial pathogens and chemical

disinfectants. Of course, you are still required to continue to meet all existing requirements. 

There are other rules being developed that may apply to your system. The future regulations

intended for the control of pathogens and DBPs are listed below. You may call the Safe

Drinking Water Hotline at 1-800-426-4791 for more information on or the current status of these

rules or other drinking water rules.
II-8

Long Term 1 Enhanced Surface Water Treatment Rule

While the Stage 1 DBPR applies to systems of all sizes, the IESWTR generally applies only to

subpart H systems serving at least 10,000 people. The exception is that the State is required to

conduct a sanitary survey at your system every three to five years. The LT1ESWTR will

strengthen microbial protection for subpart H systems serving fewer than 10,000, while also

addressing the risk tradeoff issue as small systems implement the Stage 1 DBPR. EPA believes

that the rule will generally track the approaches in the IESWTR for improved turbidity control

(including individual filter monitoring) and disinfection benchmarking and profiling.

Filter Backwash Recycling Rule

EPA is also required to develop standards for recycling of filter backwash. The Agency

published the final rule on June 8, 2001 (66 FR 31086).

Long Term 2 Enhanced Surface Water Treatment/Stage 2 Disinfection Byproducts Rules

In the 1996 Amendments to the Safe Drinking Water Act, EPA is required to finalize the Stage 2

DBPR to further address risks from disinfection byproducts, based on new health effects

research, occurrence data, and treatment information. EPA plans to also develop a Long Term 2

ESWTR to ensure that microbial protection is not compromised and may include site-specific

treatment requirements if data are available to make decisions. EPA began discussions with

stakeholders on the development of these rules in December 1998 and set up an advisory

committee in March 1999 and is currently developing rule proposals for public comment.

Ground Water Rule

EPA is also developing a rule to ensure microbial protection for ground water systems through

the use of disinfection and other strategies (wellhead protection, well construction codes,

vulnerability assessments). 
III-1

III STEP-BY-STEP PROCEDURES FOR

COMPLIANCE WITH THIS RULE

A. How can I tell if I am subject to this rule?

The Stage 1 DBPR applies to all community water systems and nontransient noncommunity

water systems that add a chemical disinfectant, as well as transient noncommunity water systems

that use chlorine dioxide (since chlorine dioxide has short-term health effects that may occur

based on limited exposure). However, systems will monitor at various frequencies depending on

source water type (subpart H and ground water) and size. Additionally, chemicals monitored may

also vary depending on system type and the primary disinfectant used. For this reason, tables that

outline the monitoring and reporting requirements are presented for each system size and type. 

If you do not know what type of water system you operate, contact your State Drinking Water

regulatory agency. If you do not know who your State agency is, call the Safe Drinking Water

Hotline at 800-426-4791.

B. What requirements am I subject to?

This section includes the federal requirements that you must comply with. The requirements for

monitoring and compliance are found in section III.D., while those for recordkeeping are found

in section III.E. and those for reporting are found in III.F.

Your State may impose different requirements, as long as those requirements are at least as

stringent as the federal requirements. Your State may also impose more requirements than the

federal requirements, such as additional monitoring or compliance with stricter standards.
III-2

You must conduct the monitoring, compliance determinations, reporting , and recordkeeping

specified in this section. In addition, you are required to conduct additional monitoring,

compliance determinations, reporting and recordkeeping if:

1. You use chlorine dioxide in treating your water. This includes any use of chlorine

dioxide, not just chlorine dioxide used for meeting disinfection requirements. Additional

requirements are found in Appendix D.

2. You use ozone in treating your water. This includes any use of ozone, not just ozone

used for meeting disinfection requirements. Additional requirements are found in

Appendix E.

3. You are a subpart H system (you treat either surface water or ground water under the

direct influence of surface water) and you use conventional filtration treatment (consisting

of coagulation, flocculation, sedimentation, and filtration) in treating your water. 

Additional requirements are found in Appendix F.

In addition, you must develop and implement a monitoring plan that specifies 1) location and

schedules for collecting all required samples, 2) procedures for calculating compliance with

MCLs, MRDLs, and treatment techniques, and 3) if receiving water as a consecutive system, or

supplying water to a consecutive system, how the entire distribution system is represented by the

monitoring plan. If you are a subpart H system serving more than 3,300 people, you must submit

your monitoring plan to the State with your first monitoring report. If you are a ground water

system or a subpart H system serving 3,300 or fewer people, you are just required to keep your

monitoring plan on file.

Finally, your system must be operated by a qualified operator. Your State will set criteria for

qualification; EPA expects that many States will have different levels of qualification, based on

type of source water, type of treatment, and population served. You should contact the State to

get further information.

C. When do I need to comply?

You must begin to comply with the requirements in the rule as of January 1, 2004. For those

chemicals that you must monitor for monthly or more frequently (such as chlorine), you must

take your first samples in January 2004. For those chemicals that you must monitor for quarterly

(such as TTHM for some systems), you must take your first samples in the January-March 2004

quarter. For those chemicals that you must monitor for annually (such as TTHM for some

systems), you must take your first samples in the month of warmest water temperature in 2004

(generally in the July-September quarter, since that is probably the period of warmest water

temperature). You need to develop and follow a monitoring plan that indicates the location and

timing of all monitoring required by this rule by the time you take your first compliance sample.
III-3

There are no requirements for you to conduct any monitoring prior to 2004 under the Stage 1

DBPR, and failure to conduct monitoring prior to 2004 is not a violation. However, EPA

believes that you should conduct monitoring on your own to see whether you need to modify

your treatment practices to meet the requirements of this rule prior to the compliance date. This

will allow you to fully consider many low-technology, lower-cost alternatives and to conduct

necessary bench- or pilot-scale testing to improve performance without going into violation.

D. What, when, and how must I monitor or test?

There are three categories of small systems that have monitoring requirements under this rule. 

They are:

- Subpart H systems that serve 500 to 9,999 people.

- Subpart H systems that serve fewer than 500 people.

- Ground water systems that serve fewer than 10,000 people.

If you do not know what type of system you are, you should contact your State agency to confirm

this information.
III-4

General Monitoring Requirements for the Stage 1 DBPR

Monitored

Parameters

System Type

Subpart H 500-

9,999 people

Subpart H

<500people

Ground water

<10,000 people

TTHM yes yes yes

HAA5 yes yes yes

Chlorine only if chlorine is used

as residual disinfectant

only if chlorine is used

as residual disinfectant

only if chlorine is used

as residual disinfectant

Chloramines only if chloramines are

used as residual

disinfectant

only if chloramines are

used as residual

disinfectant

only if chloramines are

used as residual

disinfectant

Chlorine dioxide only if chlorine dioxide

is used

only if chlorine dioxide

is used

only if chlorine dioxide

is used

Bromate only if ozone is used only if ozone is used only if ozone is used

Chlorite only if chlorine dioxide

is used

only if chlorine dioxide

is used

only if chlorine dioxide

is used

DBPP precursor

removal (enhanced

coagulation/enhanced

softening

only if conventional

filtration treatment1

 is

used

only if conventional

filtration treatment1

 is

used

No

NOTES:

1. “Conventional filtration treatment” consists of coagulation, flocculation, sedimentation, and filtration.

Monitoring for TTHM and HAA5 is based on the number of treatment plants that you operate. 

Generally, this is equal to the number of entry points into the distribution system. However, the

State can consider multiple entry points from the same aquifer as a single treatment plant for

monitoring purposes. Contact the State if you think this may apply to you. 

You may also elect to do optional monitoring in order to qualify for reduced monitoring for

certain parameters. You are not required to conduct this monitoring and conducting this

monitoring does not guarantee that you will qualify for reduced monitoring. Since not all

systems are required to do the basic monitoring, make sure that you are required to do the basic

monitoring before you decide to do the optional monitoring.
III-5

Optional Monitoring for the Stage 1 DBPR

Optional

Parameter

Purpose of Monitoring Type of System

Bromide Qualify for reduced bromate

monitoring

Any system that uses ozone

TOC Qualify for reduced TTHM and

HAA5 monitoring

Any subpart H system that does not

use conventional filtration treatment 1

Ultraviolet

(UV)

absorbance

Qualify for one of the alternative

compliance criteria for DBP

precursor removal compliance 2

Any subpart H system that uses

conventional filtration treatment

Dissolved

organic

carbon (DOC)

Qualify for one of the alternative

compliance criteria for DBP

precursor removal compliance 2

Any subpart H system that uses

conventional filtration treatment

NOTES:

1. Subpart H systems that use conventional filtration treatment are required to conduct TOC monitoring

under the DBP precursor removal (enhanced coagulation/enhanced softening) requirements. Those

systems may use this required monitoring to qualify for reduced monitoring. Other subpart H systems

may not qualify for reduced monitoring unless they conduct optional TOC monitoring.

2. UV absorbance and DOC monitoring are used to determine whether a system can meet the alternative

compliance criteria for either source water specific UV absorbance (SUVA) or treated water SUVA.
III-6

What ROUTINE TTHM, HAA5, CHLORINE, AND CHLORAMINE MONITORING must I conduct

under the Stage 1 DBPR?

Chemical Routine Frequency Where monitoring must be conducted

TTHM and

HAA5

Subpa rt H system serving 50 0-9,999 people

1 sample per plant per quarter Location representing maximum residence time1

.

Subpa rt H system serving fewer than 5 00 peo ple

1 sample per plant per year, during the

month of warmest water temperature 2

Location representing maximum residence time1.

Groun d water sy stem servin g fewer tha n 10,00 0 peop le

1 sample per plant per year, during the

month of warmest water temperature 2

Location representing maximum residence time1.

Chlorine and

Chloramines3

All systems se rving fewe r than 10 ,000 pe ople

Same time as total coliform samples are

taken

Same points as total coliform samples are taken.

NOTES:

1. If you decide to sample more frequently than the minimum required, at least 25% of all samples collected each

quarter (including those taken in excess of the required frequency) must be taken at locations that represent the

maximum residence time of the water in the distribution system. The remaining samples must be taken at locations

representa tive of at least aver age residen ce time in the en tire distribution system (accou nt for numb er of peop le

served, different sources of water, different treatment me thods)

2. If your one sample per year exceeds either 0.080 mg/L for TTHM or 0.060 mg/L for HAA5, you are not

immediately in violation. You must begin to take samples at this same location every quarter. Once you have four

quarterly samples, you will make your first compliance determination.

3. If you are a subpart H system, you may use the results of residual disinfectant concentration sampling conducted

under §141.74(b)(6)(i) for systems that do not filter or §141.74(c)(3)(i) for systems that filter, in lieu of taking

separate samples. 
III-7

What REDUCED MONITORING FOR TTHM, HAA5, CHLORINE, AND CHLORAMINES may I conduct under the

Stage 1 DBPR?

Chemical Reduced

Frequency

Where monitoring

must be conducted

Conditions to qualify for reduced

monitoring

TTHM and HAA5 Subpa rt H system serving 50 0-9,999 people

1 sample per plant per

year during month of

warmest temperature 1

In the distribution system

at a location representing

maximum residence

time.

- Annual average source water TOC 4.0

mg/L and

- Annual average TTHM 0.040 m g/L

and

- Annual average HAA5 0.030 m g/L

Subpa rt H system serving fewer than 5 00 peo ple

You ma y NOT reduce your monitoring to less than the routine frequency of one time per year

per plant.

Groun d water sy stem servin g fewer tha n 10,00 0 peop le

1 sample per plant per

three year cycle during

month of warmest

temperature 2

In the distribution system

at a location representing

maximum residence

time.

- Annual average TTHM 0.040 m g/L

and annual average HAA5 0.030 m g/L

for two consecutive years

OR

- Annual average TTHM 0.020 m g/L

and annual average HAA5 0.015 m g/L

for one year

Chlorine and

Chloramines

All systems

You ma y NOT reduce monitoring for d isinfectant residuals.

NOTES:

1. You may remain on reduced monitoring frequency as long as your TTHM concentration does not exceed 0.060

mg/L, your HAA5 concentration does not exceed 0.045 mg/L, and your annual average source water TOC level does

not exceed 4.0 mg/L. If you exceed any of these concentrations, you must revert to routine monitoring.

2. You may remain on reduced monitoring frequency as long as your TTHM concentration does not exceed 0.060

mg/L and your HAA5 concentration does not exceed 0.045 mg/L. If you exceed either the TTHM or HAA5

concentra tions, you must revert to routin e monitorin g if you do no t exceed 0 .080 mg /L for TT HM a nd 0.06 0 mg/L

for HAA5. You must go to increased (quarterly) monitoring if you exceed either 0.080 mg/L for TTHM or 0.060

mg/L for HAA5.
III-8

How do I DETERMINE IF MY SYSTEM IS IN COMPLIANCE with the TTHM and HAA5

MCLs and MRDLs in the Stage 1 DBPR?

Chemical Compliance is based on...

TTHM and HAA5 If you monitor each plant at least once per quarter

Runn ing ann ual arith metic av erage, co mputed quarter ly, of qua rterly ar ithmetic

avera ges of all sa mples colle cted (rou tine mon itoring). 

- If annual arithmetic average of quarterly averages covering any consecutive 4-quarter period

exceeds the MCL, then you are in violation.

- You must notify the public and report to the State if in violation.

If you monitor each plant no more than once per year

Annu al arithm etic aver age of a ll samples co llected (ro utine an d reduc ed mon itoring). 

- If annual sample (or average of annual samples, if you have more than one plant) exceeds the

MCL , then you must b egin quarterly monitoring a t each plant.

- If an annual ave rage excee ds the MCL and yo u are on red uced mo nitoring, you must revert to

routine mo nitoring imme diately.

Chlorine and

Chloramines

All systems

Runn ing ann ual arith metic av erage, co mputed quarter ly, of qua rterly av erages o f all

samples collected.

- If annual arithmetic average of quarterly averages covering any consecutive 4-quarter period

exceeds the MRDL, then you are in violation.

- You must notify the public and report to the State if in violation.

- If you switch between chlorine and chloramines for residual disinfection during the year,

compliance must be determined by including together all monitoring results of both chlorine

and chlora mines. 

NOTES:

1. Where compliance is based on a running annual average of monthly or quarterly samples or averages and your

failure to monitor makes it impossible to determine compliance with the MCLs or MRDLs, this failure to monitor

will be treated as a violation fo r the entire period cove red by the an nual averag e. 

2. All samples taken and analyzed under the provisions of the monitoring plan must be included in determining

complian ce, even if that num ber is greater than the minimum require d. 

3. If during the first year of monitoring, any individual quarter’s average will cause the running annual average of

that system to exceed the MCL, you are out of compliance at the end of that quarter.

E. What records do I need to keep and for how long?

You must keep records records of chemical monitoring and compliance determination for10

years. You must keep your monitoring plan as long as it is current. You must also keep

superceded monitoring plans for as long as you are required to keep monitoring results collected

under those monitoring plans.
III-9

F. What, when, and to whom must I report?

Chemical What must be reported 1, 2, 3

TTHM and

HAA5

If you monitor each plant at least once per quarter

- Number of samples taken during last quarter (routine monitoring)

- Location, date, result of each sample taken during last quarter

- Arithmetic average of all samples taken in last quarter

- Annual arithmetic average of quarterly averages for last 4 quarters

- Whether MCL was violated

If you monitor each plant no more than once per year

- Number of samples taken during last quarter (routine monitoring)

- Location, date, result of each sample taken during last quarter

- Arithmetic average of all samples taken in last quarter

- Annual arithmetic average of quarterly averages for last 4 quarters

- Whether MCL was violated

Chlorine and

Chloramines

All systems

- Number of samples taken during each month of last quarter

- Monthly arithmetic average of all samples taken in each month

- Arithmetic average of all monthly averages for last 12 months

- Whether MRDL was violated

NOTES:

1. If you are required to sample quarterly or more frequently, you must report to the State within 10 days

after the end of each quarter in which samples were collected. 

2. If you are required to sample less frequently than quarterly, you must report to the State within 10

days after the end of each monitoring period in which samples were collected. 

3. The State may choose to perform calculations and determine whether the MCL, MRDL, or treatment

technique was met in lieu of having you report that information.

G. What do I have to do if I use chlorine dioxide, ozone, or conventional

filtration treatment?

If you use chlorine dioxide, ozone, or conventional filtration treatment, you have additional

requirements under this rule. The additional requirements if you use chlorine dioxide are in

Appendix D. The additional requirements if you use ozone are in Appendix E. The additional

requirements if you use conventional filtration treatment are in Appendix F.
III-10

H. How do I minimize harm if I think I am out of compliance?

If you are out of compliance, you are required to contact your State agency within 48 hours of the

failure to comply. When you contact the State, explain the situation fully and ask for

recommendations on what to do. There are many actions that you might take that will cause the

problem to get worse. For example, if you stop adding a disinfectant if you have a TTHM

violation, you risk compromising the protection from disease-causing microorganisms. If you

stop water from entering the distribution system, you risk losing pressure in the distribution

system needed for fire fighting and to prevent infiltration. Therefore, it is important to work with

the State to address your unique circumstances.

I. Where do I go for help?

There are many sources of information available to help you meet the requirements in this rule. 

You can review EPA’s guidance manuals (see Appendix B on how to order these manuals). You

can contact your State drinking water agency. You can contact your State or regional chapters of

such organizations such as the National Rural Water Association and the American Water Works

Association. You can contact a larger water supplier in your area who might be willing to help. 

You can also contact EPA’s regional offices or the Safe Drinking Water Hotline at 800-426-

4791.

J. Are there opportunities for flexibility?

There are opportunities for systems to apply for variances and exemptions from the requirements

of this rule. You should contact your State to see what is necessary for approval. Also, the 1996

Amendments to the Safe Drinking Water Act allow for the use of point-of-use or point-of-entry

devices for compliance if the units are owned, controlled, and maintained by the public water

system or by a person under contract to the system to ensure proper operation and maintenance

and compliance with the MCL or treatment technique and the units are equipped with mechanical

warnings to ensure that customers are automatically notified of operational problems. Again, you

should contact your State for more information.
IV-1

IV. QUESTIONS AND ANSWERS ABOUT THE STAGE 1 DBPR

A. Am I in violation of the MRDL if I have to increase my chlorine or chloramine

concentration in the distribution system following a line break?

No. You are allowed to increase residual disinfectant levels in the distribution system above the

MRDLs for chlorine and chloramines (but not for chlorine dioxide) to a level and for a time

necessary to address specific microbiological contamination problems caused by circumstances

such as line breaks or cross-connection events. Compliance is not based on an individual

measurement, but on the average of all measurements taken over the previous year.

B. How do I conduct a self-audit of my drinking water system to help me evaluate whether

I am in compliance with the Stage 1 DBPR?

Since compliance is based on monitoring results, the best way to evaluate compliance is to

conduct monitoring prior to the compliance date in 2004 for any requirements that you will be

required to meet. This will allow you to evaluate your options for meeting requirements to

ensure compliance in 2004. Your options may include (but are not limited to) improved

operation of your existing treatment processes, modification of existing processes, or capital

improvements such as new technologies.

C. What are the implications of this rule for my existing permits?

You should contact the State to determine whether there are any implications.

D. How do I finance system improvements to comply with these regulations?

There are two major sources of Federal financial assistance available for water systems: the

Drinking Water State Revolving Fund (DWSRF) and the Water and Waste Disposal Loan and

Grant Program of the Rural Utilities Service (RUS) of the U. S. Department of Agriculture. 

The 1996 SDWA Amendments authorized $9.6 billion for the DWSRF program. To date,

Congress has appropriated $4.2 billion, which includes $825 million for the program in Fiscal

Year 2001. By the end of September 2000, States had been awarded $3.2 billion in capitalization

grants and, from that, had provided more than $2.8 billion in assistance to eligible drinking water

systems. The Federal capitalization grant, together with State matching funds, is currently

making available about $1 billion per year. States have considerable discretion in designing their

DWSRF program, and have the option of offering special assistance to systems that the State

considers to be disadvantaged. Special assistance may include principal forgiveness, a negative

interest rate, an interest rate lower than that charged to non-disadvantaged systems, and extended

repayment periods of up to 30 years. Federal law allows DWSRF assistance to be provided to

both publicly- and privately-owned systems, although some States are unable or choose not to

provide assistance to privately-owned systems.

EPA recognizes that public water systems and States face a significant challenge in

implementing new requirements that are needed to ensure the continued provision of safe

drinking water. While the DWSRF program is proving to be a significant source of funding, it
IV-2

cannot be viewed as the only source of funding. It will take a concerted effort on the part of

Federal, State and local governments, private business, and utilities to address the significant

infrastructure needs identified by public water systems. In order to ensure that the DWSRF

program is used to focus attention on the highest priority needs, all States must give priority to

those drinking water infrastructure improvement projects that will have the greatest public health

benefit or ensure compliance with SDWA. State DWSRF programs are currently making loans

available to the highest ranked projects on their lists and are also using a portion of the grants to

support other important drinking water program activities. 

The RUS program is focused on providing a safe, reliable water supply and wastewater treatment

to residents of rural America. The program offers a combination of low interest loans and grants

to systems serving rural areas and cities and towns of up to 10,000 persons and which are

publicly owned (including Native American systems) or operated as not-for-profit corporations. 

In recent years the RUS program has typically offered assistance totaling about $1.3 billion per

year, about 60% of which is directed to drinking water projects. Thus, about $780 million per

year is available for rural drinking water systems from this program. Together with the

approximately $1 billion per year being made available through the DWSRF, this results in a

total of about $1.78 billion per year of Federal financial assistance available for drinking water.

Other Federal financial assistance programs exist that may help systems with SDWA compliance

related expenditures. However, these other programs are not generally as large or focused on

drinking water as are the DWSRF and RUS programs. EPA's Environmental Financial Advisory

Board has developed a "Guidebook of Financial Tools", which offers a comprehensive summary

of public and private programs and mechanisms for paying for drinking water and other

environmental systems. The handbook is available through EPA's web site at:

http://www.epa.gov/efinpage/guidbk98/index.htm.

The Federal financial assistance programs described previously clearly face numerous,

competing demands on their resources. EPA's 1995 Drinking Water Infrastructure Needs

Survey identified a total 20-year need for all systems of $138.4 billion. The single largest

category of need (accounting for over half of the total need) is installation and rehabilitation of

transmission and distribution systems. Treatment needs constitute the second largest category of

need, accounting for over 1/4 of total needs. Storage and source rehabilitation and development

constitute the remaining major categories of needs. Thus, systems seeking financial assistance

for installation of DBP treatment are competing for resources with systems seeking assistance for

compliance with other rules and with systems seeking resources for basic infrastructure repair

and replacement. In seeking to meet these numerous and competing needs, the Agency

recognizes the importance of priority setting for financial assistance programs. Systems having

the financial capability to secure funding through the capital markets should do so, leaving the

Federal financial assistance programs to assist the truly needy systems. Since the demand for

assistance will likely outstrip the supply of assistance, you may want to discuss an exemption

with your State, which, if granted, will provide additional time for you to secure financial

assistance.
V-1

V. THE COMPLIANCE ASSURANCE PROCESS

A. How is my system’s compliance with the Stage 1 DBPR requirements determined?

Compliance calculations are based on the results of the monitoring you are required to conduct

(see Section III for details). Some States conduct monitoring for small systems, either on a

regulatory basis or on a fee-for-service basis. You calculate compliance using the procedures

identified in Section III; States also may just require you to submit your analytical results and the

State will calculate compliance.

B. If I discover a violation, how can I work with my State to correct it?

If you discover that you have violated the Stage 1 Disinfectants and Disinfection Byproducts

Rule, you need to call the primacy agency (generally your State drinking water agency, but it may

be EPA or an approved tribe) to discuss the situation. The primacy agency is the entity which is

responsible for enforcing drinking water regulations.

You remain ultimately responsible for resolving the violation. However, if the violation can be

easily and expeditiously resolved, the primacy agency may be willing to work with you to

remedy the problem. If the cause of the violation is unknown, you may choose to work with the

primacy agency and/or a third-party contractor to determine how to correct the violation and

create a long-term compliance solution.

The primacy agency may issue a Notice of Violation (NOV), Administrative Order (AO), and/or

a Bilateral Compliance Agreement (BCA) notifying you of the violation and ordering you to

resolve the problem causing the violation(s). The primacy agency is authorized to demand a

penalty for any violation of the Stage 1 Disinfectants and Disinfection Byproducts Rule. Failure

to expeditiously remedy the cause of the violation(s) may result in a federal or State civil judicial

enforcement action demanding both injunctive relief and a significant penalty.

You may also be required to provide public notice and/or provide an alternate water source, such

as bottled water, if the violation impacts public health or may cause an imminent and substantial

endangerment to public health or the environment. Public notice means providing health impact

information to people who consume the water your system treats.

C. If EPA or the State discovers a violation, what might be its response?

To maximize compliance, EPA and States implement a balanced program of compliance

assistance, compliance incentives, and traditional law enforcement through the courts. Small

systems that must comply with complicated new statutes or rules often want to do the right thing,

but may lack the requisite knowledge, resources, or skills. Compliance assistance information

and technical advice helps small systems to understand and meet their obligations. Compliance

incentives, such as EPA’s Small Business Policy, encourage persons to voluntarily discover,

disclose, and correct violations before they are identified by the government. A strong law

enforcement program protects all of us by targetting persons who neither comply nor cooperate to

address their problems.
V-2

EPA and States use a variety of methods to determine whether systems are complying, including

inspecting facilities, reviewing records and reports, and responding to citizen complaints. If EPA

or a State learns that a system is violating the law, we may file an enforcement action seeking

penalties of up to $27,500, per violation, per day. The proposed penalty in a given case will

depend on many factors, including the number, length, and severity of the violations, the

economic benefit obtained by the violator, and its ability to pay. EPA has policies in place to

ensure penalties are calculated fairly. These policies are available to the public. In addition, any

system charged with a violation has the right to a public hearing.

In summary, EPA recognizes that we can achieve the greatest possible protection by encouraging

small systems to work with the State or us to discover, disclose, and correct violations. That is

why we have issued self disclosure, small business, and small community policies to eliminate or

reduce penalties for small and large entities that cooperate with EPA to address compliance

problems. In addition, we have established compliance assistance centers to serve over a million

small businesses. For more information on these and other programs for small businesses, please

contact the Small Business Ombudsman Clearinghouse/Hotline at 800-368-5888 (or 202-260-

1211 from the Washington, DC metropolitan calling area).

D. What is the legal status of the guide?

A judge can look at a compliance guide to help determine what penalty is appropriate or

reasonable. The content of the guide cannot otherwise be reviewed by the court.

In this compliance guide, we have tried to make clear what you must do to comply with the Stage

1 Disinfectants and Disinfection Byproducts Rule, as required by SBREFA. We hope you find

this presentation of regulatory requirements useful and the additional information helpful in

reaching and maintaining compliance.
APPENDICES

A. Glossary of terms used in this guide

B. Where to obtain more information

C. Questionaire - How useful was this guide?

D. Requirements for systems that use chlorine dioxide.

E. Requirements for systems that use ozone.

F. Requirements for systems that use conventional filtration treatment.
A-1

APPENDIX A - GLOSSARY OF SELECTED TERMS USED IN

THIS GUIDE

Alternative compliance criteria means the eight criteria in the Stage 1 DBPR that systems may

use to demonstrate compliance with the disinfection byproduct precursor (TOC) removal

requirements in lieu of the requirement to remove specified levels of disinfection byproduct

precursors.

Conventional filtration treatment means a series of processes including coagulation, flocculation,

sedimentation, and filtration resulting in significant particulate removal.

Disinfection byproduct precursors means organic or inorganic compounds that react with

disinfectants to form disinfection byproducts.

Enhanced coagulation means the addition of sufficient coagulant for improved removal of

disinfection byproduct precursors by conventional filtration treatment.

Enhanced softening means the improved removal of disinfection byproduct precursors by

precipitative softening.

GAC10 means granular activated carbon filter beds with an empty-bed contact time of 10

minutes based on average daily flow and a carbon reactivation frequency of every 180 days.

Ground water under the direct influence of surface water (GWUDI) means any water beneath the

surface of the ground with significant occurrence of insects or other macroorganisms, algae, or

large-diameter pathogens such as Giardia lamblia or Cryptosporidium or significant and

relatively rapid shifts in water characterisitics such as turbidity, temperature, conductivity, or pH

which closely correlate to climatological or surface water conditions. States were required to

determine whether ground water was under the influence of surface water for all systems by

1999.

Haloacetic acids (five) (HAA5) mean the sum of the concentrations in milligrams per liter of the

haloacetic acid compounds (monochloroacetic acid, dichloroacetic acid, trichloroacetic acid,

monobromoacetic acid, and dibromoacetic acid), rounded to two significant figures after

addition.

Maximum residual disinfectant level (MRDL) means a level of a disinfectant added for water

treatment that may not be exceeded at the consumer's tap without an unacceptable possibility of

adverse health effects. For chlorine and chloramines, a PWS is in compliance with the MRDL

when the running annual average of monthly averages of samples taken in the distribution

system, computed quarterly, is less than or equal to the MRDL. For chlorine dioxide, a PWS is

in compliance with the MRDL when daily samples are taken at the entrance to the distribution

system and no two consecutive daily samples exceed the MRDL. MRDLs are enforceable in the

same manner as maximum contaminant levels under the Safe Drinking Water Act. There is

convincing evidence that addition of a disinfectant is necessary for control of waterborne

microbial contaminants. Operators may increase residual disinfectant levels of chlorine or
A-2

chloramines (but not chlorine dioxide) in the distribution system to a level and for a time

necessary to protect public health to address specific microbiological contamination problems

caused by circumstances such as distribution line breaks, storm runoff events, source water

contamination, or cross-connections.

Maximum residual disinfectant level goal (MRDLG) means the maximum level of a disinfectant

added for water treatment at which no known or anticipated adverse effect on the health of

persons would occur, and which allows an adequate margin of safety. MRDLGs are

nonenforceable health goals and do not reflect the benefit of the addition of the chemical for

control of waterborne microbial contaminants.

Pathogens means disease-causing organisms, such as some bacteria, viruses, and protozoa.

Subpart H systems means public water systems using surface water or ground water under the

direct influence of surface water as a source that are subject to the requirements of the Surface

Water Treatment Rule.

SUVA means Specific Ultraviolet Absorption at 254 nanometers (nm), an indicator of the humic

content of a water. It is a calculated parameter obtained by dividing a sample’s ultraviolet

absorption at a wavelength of 254 nm (UV254) (in m-1) by its concentration of dissolved organic

carbon (DOC) (in mg/L).

Total Organic Carbon (TOC) means total organic carbon in mg/L measured using heat, oxygen,

ultraviolet irradiation, chemical oxidants, or combinations of these oxidants that convert organic

carbon to carbon dioxide, rounded to two significant figures. 
B-1

APPENDIX B - WHERE TO OBTAIN MORE INFORMATION

EPA has developed a series of guidance manuals to support the Stage 1 Disinfectants and

Disinfection Byproducts Rule. The manuals will aid EPA, State agencies, and you in

implementing the rule, and will help to ensure that implementation is consistent.

Guidance Manual for Enhanced Coagulation and Enhanced Precipitative Softening (EPA

815-R-99-012)

Objective: To assist utilities in implementing, monitoring, and complying with the treatment

technique requirements in the final Stage 1 Disinfectants and Disinfection Byproducts Rule and

to provide guidance to State staff responsible for implementing the treatment requirements.

Contents: The manual provides detailed information on the total organic carbon (TOC) removal

requirement; explains how to set an alternative TOC removal percentage under the Step 2

procedure; details monitoring, reporting, and compliance requirements; and discusses strategies

that can be employed to mitigate the potential secondary effects on plant performance due to

implementation of the treatment technique.

Alternative Disinfectants and Oxidants Guidance Manual (EPA 815-R-99-014)

Objective: To provide technical data and engineering information on disinfectants and oxidants

that are not as commonly used as chlorine, so that systems can evaluate options for developing

disinfection schemes to control water quality problems such as zebra mussels and Asiatic clams,

and oxidation to control water quality problems associated with iron and manganese.

Contents: The manual discusses six disinfectants and oxidants: ozone, chlorine dioxide,

potassium permanganate, chloramines, ozone/hydrogen peroxide combinations, and ultraviolet

light. A decision tree is provided to assist in evaluating which disinfectant(s) is most appropriate

given certain site-specific conditions (e.g., water quality conditions, existing treatment and

operator skill). The manual also contains a summary of existing alternative disinfectants used in

the United States and cost estimates for the use of alternative disinfectants. 

M/DBP Simultaneous Compliance Manual (EPA 815-R-99-015)

Objective: To assist public water systems on complying simultaneously with various drinking

water regulations (e.g., Stage 1 Disinfectants and Disinfection Byproducts Rule, Interim

Enhanced Surface Water Treatment Rule, Lead and Copper Rule and the Total Coliform Rule). 

The manual discusses operational problems you may encounter when implementing these rules.

Contents: The manual provides detailed information on the requirements in the Stage 1

Disinfectants and Disinfection Byproducts Rule and the Interim Enhanced Surface Water

Treatment Rule.

For more information, contact EPA's Safe Drinking Water Hotline, 1 (800) 426-4791, or see

the Office of Ground Water and Drinking Water web page at http://www.epa.gov/safewater/

standards.html. The rule is available at www.epa.gov/safewater/mdbp/dbpfr.html.

To order a copy of guidance manuals you may contact the Safe Drinking Water Hotline at (800)

426-4791 or you may download an electronic version from the OGWDW website at

http://www.epa.gov/safewater/mdbp/implement.html.
C-1

APPENDIX C - QUESTIONNAIRE

Title of Rule or Program: 

Name of Commenter (optional): 

Please take a moment to let us know if you found this guide useful by answering the following

questions. Thank you; your feedback is important to us.

1. I could easily understand what requirements I must meet. 

2. The guide is written in understandable language. 

3. The guide helped me understand the steps I must take to comply with the rule. 

4. If you have suggestions to improve the guide, please indicate below.

 

Please fold on dashed line and return by mail. Thank you.

— — — — — — — — — — — — — — — — — — — — — — — — — — — — — — —

Affix

Postage

Here

U.S. EPA

Regulatory Management Division

Mail Code 2136

1200 Pennsylvania Avenue, NW

Washington, DC 20460
D-1

APPENDIX D. What do I have to do if I use chlorine dioxide?

What ROUTINE MONITORING must I conduct under the Stage 1 DBPR?

Chemical Frequency Where monitoring must be conducted

Chlorite 1 Daily Entrance to the distribution system.

1 3-samp le set per mo nth Near first customer (1), location representative of average residence time

(1), location representative of maximum residence time in distribution

system (1).

Additional: On any day

following any d aily

sample that e xceeds 1 .0

mg/L, you must take a 3-

sample set

Near first customer (1), location representative of average residence time

(1), location representative of maximum residence time in distribution

system (1). The system may use results to meet monthly 3-sample set

monitoring requirement if the monthly 3-sample set has not yet been

taken.

Chlorine

Dioxide

Daily Entrance to the distribution system.

Additiona l: For any daily

sample that e xceeds 0 .8

mg/L, you must take 3

samples the following day

• If chlorine dioxide or chloramines are used for residual disinfection or

chlorine with no booster chlorination is used for residual disinfection:

all samples as close as possible to the first customer at intervals of at

least 6 hours

• If chlorine with booster chlorination is used for residual disinfection:

one samp le as close as p ossible to the first c ustomer, o ne sample at a

location representative of averag e residence time, one samp le as close

as possible to the end of the distribution system (reflecting maximum

residence time)

NOTES:

1

 Not required for transient noncommunity water systems

What REDUCED MONITORING may I conduct under the Stage 1 DBPR?

Chemical Frequency Where monitoring must

be conducted

Conditions for reduced

monitoring

Chlorite (d aily)1 No reduced monitoring allowed NA NA

Chlorite

(monthly) 1

1 3-sample set per quarter Near first customer (1),

location representative of

average residence time(1),

location representative of

maximum residence tim e in

distribution system. (1)

• No daily o r monthlt

sample has exceeded the

MCL and

• No additional monitoring

has been required and

• No qua rterly sample

exceeds the MCL

Chlorine Dioxide No reduced monitoring allowed NA NA

NOTES:

1

 Not required for transient noncommunity water systems
D-2

How do I DETERMINE IF MY SYSTEM IS IN COMPLIANCE with the MCLs and MRDLs of

the Stage 1 DBPR?

Chemical Compliance is based on...

Chlorite Averag e of 3-sample sets.

• If arithmetic ave rage of any 3 -sample set in the month exc eeds the M CL, the system is in

violation.

• The system must notify the public and report to the State if in violation.

Chlorine

Dioxide—

Acute

Violation

Consecutive daily samples collected.

• If any daily sample taken at entrance to distribution system exceeds 0.8 mg/L, and on the

following da y one or mo re of the three sa mples taken in the distribution system excee ds 0.8

mg/L, the system is in acute violation.

• The system must take immediate corrective action to lower the level of chlorine dioxide below

0.8 mg/L, and within 24 hours notify the public and consult with the State.

• Failure to take samples in the distribution system following an exceedance of the MRDL at the

entrance to the distribution system is also an a cute violation . System must, w ithin 24 hou rs, notify

public of acute violation and consult with the State.

Chlorine

Dioxide—

Nonac ute

Violation

Consecutive daily samples collected.

• If any two consecutive daily samples taken at entrance to distribution system exceed 0.8 mg/L,

and all distribution system samples are below 0.8 mg/L, the system is in nonacute violation.

• The system must take imm ediate corrective action to lower the lev el of chlorine d ioxide be low0.8

mg/L, notify the public and report to the State.

• Failure to take samples at the distribution system entrance following an exceedance of the MRDL

is also a violation. System must notify public of nonacute violation and report to the State.

What do I have to REPORT to the State under the Stage 1 DBPR?

Chemical What must be reported1, 2, 3

Chlorite • Number of entry point samples taken each month for last three months

• Location, date, result of each sample (both entry point and distribution system samples) taken

during last three months

• For each month in the reporting period, the arithmetic average of all samples taken in each 3-

sample set taken in the distribution system

• Whether MCL violations occurred, in which month(s) violations occurred, and how many times

MCL violations oc curred ea ch month

Chlorine

Dioxide

• Dates, results, locations of samples taken during last quarter

• Whether MRDL was exceeded

• Whether MRD L was exceeded in any two consecutive daily samples and whether resulting

violation was acute or no nacute

NOTES:

1. Systems required to sample quarterly or more frequently must report to the State within 10 days after the end of

each qua rter in which sam ples were co llected. 

2. Systems required to sample less frequently than quarterly must report to the State within 10 days after the end of

each monitoring period in which samples were collected.

3. The State may choose to perform calculations and determine whether the MCL, MRDL, or treatment technique

was met in lieu of having the system report that information.
E-1

APPENDIX E. What do I have to do if I use ozone?

What ROUTINE MONITORING must I conduct under the Stage 1 DBPR?

Chemical Frequency Where monitoring must be conducted

Broma te 1 sample per ozone plant

per mon th

Entrance to the distribution system.

Bromide 1 sample per ozone plant

per mon th

In source water (only required if the system wishes to qualify for reduced

bromate monitoring).

What REDUCED MONITORING may I conduct under the Stage 1 DBPR?

Chemical Frequency Where monitoring

must be conducted

Conditions for reduced

monitoring

Broma te 1 sample per ozone plant per

quarter

Entrance to the

distribution system.

• Annual average source water

bromide concentra tion <0.05 mg/L1

Bromide No red uced mo nitoring if

wishing to conduct reduced

bromate monitoring

NA NA

NOTES:

1

 System must base the initial qualification for reduced monitoring on at least one year’s worth of monitoring and

must resume monthly bromate monitoring if running annual average of source water bromide 0.05 mg/L.

How do I DETERMINE IF MY SYSTEM IS IN COMPLIANCE with the bromate MCL in the

Stage 1 DBPR?

Chemical Comp liance is ba sed on... 1, 2

Broma te Running annual arithmetic average, computed quarterly, of monthly samples (or average of

all samples taken during the month if more than 1 sam ple was collected).

• If average o f samples co vering any co nsecutive 4-q uarter perio d exceed s the MCL, the system is

in violation.

• The system must notify the public and report to the State if in violation.

NOTES:

1. Where compliance is based on a running annual average of monthly or quarterly samples or averages and the

system’s failure to m onitor mak es it impossib le to determine comp liance with the M CLs or M RDLs, this fa ilure to

monitor will b e treated as a violation for the entire period covered by the annua l average. 

2. All samples taken and analyzed under the provisions of the monitoring plan must be included in determining

complian ce, even if that num ber is greater than the minimum require d. 

3. If during the first year of monitoring, any individual quarter’s average will cause the running annual average of

that system to exceed the MCL, the system is out of compliance at the end of that quarter.
E-2

What do I have to REPORT to the State under the Stage 1 DBPR?

Chemical What must be reported1, 2, 3

Broma te • Number of samples taken during last quarter

• Location, date, result of each sample taken during last quarter

• Arithmetic average of monthly arithmetic averages of all samples taken in last year

• Whether MCL was exceeded

NOTES:

1. Systems required to sample quarterly or more frequently must report to the State within 10 days after the end of

each qua rter in which sam ples were co llected. 

2. Systems required to sample less frequently than quarterly must report to the State within 10 days after the end of

each mo nitoring perio d in which sam ples were co llected. 

3. The State may choose to perform calculations and determine whether the MCL, MRDL, or treatment technique

was met in lieu of having the system report that information.
F-1

APPENDIX F. What do I have to do if I am a subpart H system

with conventional filtration treatment?

If you are a subpart H system with conventional filtration treatment, you must (a) remove organic

disinfection byproduct precursors (DBPP), measured as total organic carbon, through enhanced

coagulation or enhanced softening, (b) demonstrate that your DBPP cannot be removed through

these processes, or (c) demonstrate that the level or nature of your DBPP does not require their

removal.

There are many ways to achieve compliance with this requirement. You should review the

“Guidance Manual for Enhanced Coagulation and Enhanced Precipitative Softening “(EPA 815-

R-99-012), which is available as indicated in Appendix B of this manual. This guidance manual

will assist you in implementing, monitoring, and complying with the treatment technique

requirements in the Stage 1 Disinfectants and Disinfection Byproducts Rule. The guidance

manual provides detailed information on the total organic carbon (TOC) removal requirement;

explains how to set an alternative TOC removal percentage under the Step 2 procedure; details

monitoring, reporting, and compliance requirements; and discusses strategies that can be

employed to mitigate the potential secondary effects on plant performance due to implementation

of the treatment technique. Because the “Guidance Manual for Enhanced Coagulation and

Enhanced Precipitative Softening “ is so detailed, its specific guidance is not repeated here. 

Instead, you should review this appendix to determine whether the requirement applies to you. If

this requirement applies to you, you should refer to the guidance manual.

What is the goal of enhanced coagulation and enhanced precipitative softening?

The goal of enhanced coagulation and precipitaive softening is to provide additional removal of

the natural organic material (referred to as total organic carbon or “TOC”) that is a precursor to

DBP formation. TOC and disinfectants commonly used in drinking water treatment can react to

form DBPs. Adding additional amounts of coagulant or lime to coagulation or softening

treatment trains, respectively, can increase the removal of TOC and thereby lower DBP levels in

finished water. 

Which systems does the treatment technique apply to?

The treatment technique applies to subpart H systems (systems using surface water or

groundwater under the direct influence of surface water) that use conventional treatment. 

Conventional treatment is defined as coagulation or lime addition, flocculation, sedimentation,

and filtration. 

How is the treatment technique implemented?

Public water systems (PWSs) are required to remove a specified percentage of TOC from the

raw water. The percent removal is based on raw water TOC and alkalinity levels. A pair of TOC

samples must be taken simultaneously in the raw water and no later than the combined filter

effluent at least once per month to calculate the percent removal and demonstrate compliance via

a running annual average. If a PWS is unable to meet the required TOC removal, the State may
F-2

set an alternative TOC percent removal based on jar or pilot testing that reflects the treatability

of their water. PWSs may also use one of the alternative compliance criteria to demonstrate

compliance. 

What are alternative compliance criteria?

Some systems may have water that is low in DBPPs or have DBPPs that are non-reactive or

cannot be removed through enhanced coagulation or enhanced softening. For these systems,

EPA has designated different standards for demonstrating compliance, known as alternative

compliance criteria. There are six alternative compliance criteria that are available to all systems,

plus two more that are available only to systems that use precipitative softening. They are

discussed in detail in the “Guidance Manual for Enhanced Coagulation and Enhanced

Precipitative Softening“.

What ROUTINE MONITORING must I conduct under the Stage 1 DBPR?

Chemical Frequency Where monitoring must be conducted

TOC and

Alkalinity

(conventional

treatment)

- Two TOC samples per plant

per month

- One alkalinity sample per

plant per month at same time as

source water TOC sample is

taken

TOC (two samples)

• In source water prior to any treatment

• No later than the point of combined filter effluent

turbidity monitoring and representative of filtered

water 

Alkalinity

• Same location as source water TOC sample is taken.

What REDUCED MONITORING may I conduct under the Stage 1 DBPR?

Chemical Frequency Where monitoring must be

conducted

Conditions for reduced

monitoring

TOC and

Alkalinity

(conventional

treatment)

- Two TOC samples

per plant per quarter

- One alkalinity

sample per plant per

quarter at same time

as source water TOC

sample is taken

TOC (two samples)

• In source water prior to any

treatment 

• No later than the point of

combined filter effluent turbidity

monitoring and representative of

filtered water 

Alkalinity

• Same location as source water

TOC sample is taken.

Average treated water TOC <

2.0 mg/L for 2 consecutive years

or <1.0 mg/L for 1 year
F-3

How do I DETERMINE IF MY SYSTEM IS IN COMPLIANCE with the TOC removal

requirements of the Stage 1 DBPR?

Chemical Compliance is based on...

TOC (conventional

treatment)

“Step 1” or “Step 2” removal targets or alternative compliance criteria 1,2 Refer to

the “Guidance Manual for Enhanced Coagulation and Enhanced Precipitative

Softening” for further information.

NOTES:

1. Where compliance is based on a running annual average of monthly or quarterly samples or averages

and the system’s failure to monitor makes it impossible to determine compliance with the treatment

technique, this failure to monitor will be treated as a monitoring violation for the entire period covered by

the annual average. 

2. All samples taken and analyzed under the provisions of the monitoring plan must be included in

determining compliance, even if that number is greater than the minimum required.