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Water: Stage 2 DBP Rule

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Are you trying to implement the new Stage 2 Disinfectants and Disinfection Byproducts (DBP) Rule? Do you have questions about the provisions of the rule? If so, this web site should help you out!

This page is designed to provide you with guidance materials, training modules and fact sheets to help you with the implementation of the Stage 2 DBP rule.

Public Water System Guidance
State Guidance
Point of Contact List

Public Water System Guidance

EPA provides guidance documents to help states and public water systems implement the rules.

You will need Adobe Reader to view some of the files on this page. See EPA's PDF page to learn more.

Quick Reference Guides for Stage 2 DBP Rule
This document provides a simple and straightforward description of the rule, critical deadlines and requirements for drinking water systems and states, and information on monitoring requirements.

Fact Sheets for Stage 2 DBP Rule

Operational Evaluation Guidance Manual
Description: This manual (formerly titled the Significant Excursions Guidance Manual) will assist systems in meeting the requirements for operational evaluations under the Stage 2 DBP rule. The guidance manual describes the requirements for operational evaluations and provides guidance for documenting and reporting an operational evaluation level exceedance. The guidance manual provides a methodology for identifying the cause of operational evaluation levels exceedances and the options available to minimize further operational evaluation level exceedances.
Target audience: Public water systems, states.

Initial Distribution System Evaluation (IDSE) Guidance Manual and Tool
Description: This manual explains IDSE requirements to utilities and provides guidance to States and EPA (since EPA will be performing activities in some States prior to those States receiving primacy) on reviewing completed IDSE plans and reports. The manual covers the four options for fulfilling the IDSE requirement: Very Small System Waiver, 40/30 Certification, Standard Monitoring, and System Specific Studies. Flow charts, tear-out requirements sheets, templates, and examples are provided to help utilities understand requirements and options for complying. This technical manual provides detail on how utilities can use different types of data to help select monitoring sites for the evaluation. The IDSE Tool is a web-based electronic wizard designed to help water systems through the entire IDSE process. Systems first use the Wizard to determine which IDSE option is best for them. The IDSE Tool then creates custom forms for the selected option and guides the system step-by-step through the forms that can then be submitted electronically. The IDSE tool is also available on CD-ROM.
Target audience: Public water systems, states.

Simultaneous Compliance Guidance Manual for Stage 2 Rules
EPA 815-R-07-017 May 2007
Description: This manual discusses the issues that systems will face as they evaluate and implement changes necessary to comply with the Stage 2 DBPR and the LT2ESWTR, while still being required to comply with earlier rules such as the Total Coliform Rule and Lead and Copper Rule. Some of the changes that systems may make can have compliance or operational consequences if not properly designed, implemented, and monitored. This manual builds on a similar manual developed for the Stage 1 rules, incorporating new research and case studies, and is presented in a more user-friendly manner. EPA has developed this guidance manual to provide systems and states with information on operational and capital changes and approaches to enable systems to evaluate different compliance strategies and technologies.
Target audience: Public water systems making treatment and operational changes to comply, states.

Consecutive Systems Guidance Manual for the Stage 2 DBPR
815-R-09-017 March 2010
Description: This manual discusses requirements for consecutive systems (public water systems that receive fully treated water from other public water systems) to comply with Stage 2 DBPR monitoring and MCL requirements. Most previous drinking water rules, including the Stage 1 DBPR, have not specifically addressed requirements for consecutive systems to comply with. States have therefore implemented previous rules in a variety of ways. Since 1) DBPs are one of a limited number of contaminants that generally increase in the distribution system, 2) over 250 million people are exposed to DBPs, including millions served by nearly 10,000 consecutive systems, and 3) there are fewer options for control of DBPs once they are formed (as is the case for consecutive systems), EPA has developed this guidance manual to provide information on operational and capital changes and strategies that will enable consecutive systems to comply with this rule.
Target audience: Consecutive systems, States, EPA Regions. 

Complying with the Stage 2 Disinfectants and Disinfection Byproducts Rule: Small Entity Compliance Guide
Description: This manual contains a general introduction and background for the Stage 2 Disinfectants and Disinfection Byproducts Rule (DBPR), describes the requirements of the rule that apply to small systems (those serving fewer than 10,000 people), and provides step-by-step guidance on how small systems can comply with Stage 2 DBPR requirements (IDSE requirements are addressed in a separate manual). Examples of actions systems might take to comply with the rule are given throughout the guide. 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 (SBREFA) of 1996.
Target audience: Small public water systems, states.


State Guidance

The Stage 2 Disinfectants and Disinfection Byproducts Rule (Stage 2 DBPR) Implementation Guidance
EPA 816-R-07-007, August 2007
This draft guidance will help EPA regions and states with implementation of the rule’s provisions. Along with a summary of the rule, this document contains guidance for preparing state primary enforcement authority (primacy) revision applications, rule fact sheets, a quick reference guide, and flowcharts illustrating rule requirements.

State Preference Table for Stage 2 DBPR 40/30 Certification Supplemental Information


If you are implementing the Stage 2 rule and are interested in trainings please visit the EPA's microbial and disinfection byproducts training site for a list of trainings, webcasts, and other training opportunities available.

Point of Contact List
In various places in guidance it is suggested that systems contact EPA or the state. Regardless of whether EPA or the state would be doing certain reviews, certain states have indicated still being the point of contact for questions or interactions with systems. In order to provide clarity about who to contact, the following is a point of contact list. This list will be updated periodically as our implementation relationship with states evolve.

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