Stage 2 Rule

Welcome to the Stage 2 Disinfectants and Disinfection Byproducts Rule (Stage 2 DBP rule) page. On this site you will find links to the rule, fact sheets as well as general information about the history of the rulemaking.

Stage 2 DBP Rule Federal Register Notices and Fact Sheets

The Stage 2 DBP rule is one part of the Microbial and Disinfection Byproducts Rules (MDBPs), which are a set of interrelated regulations that address risks from microbial pathogens and disinfectants/disinfection byproducts. The Stage 2 DBP rule focuses on public health protection by limiting exposure to DBPs, specifically total trihalomethanes (TTHM) and five haloacetic acids (HAA5), which can form in water through disinfectants used to control microbial pathogens. This rule will apply to all community water systems and nontransient noncommunity water systems that add a primary or residual disinfectant other than ultraviolet (UV) light or deliver water that has been disinfected by a primary or residual disinfectant other than UV.

Federal Register Notices

 
• January 4, 2006 Federal Register Notice
 
• Corrections to the Federal Register Notice
         
       
  • November 14, 2006
       
  • June 29, 2006
         
       
  • January 27, 2006
         
     
   
 
• Fact Sheet
      This fact sheet provides information on the basic requirements, the public health and environmental benefits, and estimated costs associated with the rule.
  EPA 815-F-05-003, December 2005
         
       
  • Read the Fact Sheet online
       
  • PDF File (4pp, 40K)
         
     
   

Quick Reference Guide to 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.

• Stage 2 DBP rule Quick Reference Guides

Questions and Answers

• Basic Information about the Stage 2 Rule
• Information about Chloramine in Drinking Water

Stage 2 DBP Rule Supporting Documents

The following documents were developed to support the final rule-making.

• Occurrence Document
  • Occurrence Assessment for the Final Stage 2 Disinfectants and Disinfection Byproducts PDF (209pp, 3M)
    EPA 815-R-05-011
    December, 2005
    
    
• Cost and Technologies
  • Technologies and Costs Document for the Final Long Term 2 Enhanced Surface Water Treatment Rule and Final Stage 2 Disinfectants and Disinfection Byproducts Rule PDF (309pp, 1M)
    EPA 815-R-05-013
    December, 2005
    
    
• Economic Analysis
  • Economic Analysis for the Final Stage 2 Disinfectants and Disinfection Byproducts Rule PDF (432pp, 2M)
    EPA 815-R-05-010
    December 2005
    • Appendix One PDF (237pp, 911K)
    • Appendix Two PDF (282pp, 983K)
    • Appendix Three PDF (315pp,1M)
      
      
• For additional supporting information related to this rule-making, visit docket number EPA-HQ-OW-2002-0039 at Regulations.gov

Rulemaking History

Stage 2 DBP Rule Proposal Federal Register Notice

Stake Holder Meetings

Agreement in Principle

The basic framework for the rule was developed by the Stage 2 Microbial/Disinfection Byproductfederal advisory committee which was comprised of state and local government, environmental, public health and water industry stakeholders.