Stage 2 Disinfection Byproducts Rule (DBPR)

Stage 2 Overview

The Stage 2 Disinfection Byproducts Rule (DBPR) was promulgated in January 2006 and applies to all community and non-transient non-community (NTNC) water systems that add a primary or residual disinfectant other than ultraviolet light (UV) or deliver water that has been treated with a primary or residual disinfectant other than UV. Systems that purchase disinfected water are included in this rule.

The Stage 2 DBPR builds on the existing Stage 1 DBPR and provides increased health protection.
Stage 1 monitoring will end when Stage 2 monitoring begins.

Key Resources

Important deadlines are summarized in the following table:

Table 1. Stage 2 DBP Rule Deadlines
Public Water Systems	Actions and Deadlines
Public Water Systems	Schedule number	Submit IDSE standard monitoring plan, system specific study plan or 40/30 certification	Complete an initial distribution system evaluation (IDSE)	Submit IDSE report	Begin Stage 2 compliance monitoring
CWS = Community Water Systems. NTNCWS = Non-Transient Non-Community Water Systems.
State may grant up to an additional two years for systems making capital improvements.
* Systems under 10,000 population that have to monitor for Cryptosporidium may begin Stage 2 compliance monitoring October 1, 2014.
CWS and NTNCWS serving at least 100,000	1	10/1/2006	9/30/2008	1/1/2009	4/1/2012
CWS and NTNCWS serving 50,000 - 99,999	2	4/1/2007	3/31/2009	7/1/2009	10/1/2012
CWS and NTNCWS serving 10,000 - 49,999	3	10/1/2007	9/30/2009	1/1/2010	10/1/2013
CWS serving fewer than 10,000	4	4/1/2008	3/31/2010	7/1/2010	10/1/2013*
NTNCWS serving fewer than 10,000	4	N/A	N/A	N/A	10/1/2013*

Stage 2 DBPR Information

Additional Resources

See the following for more Stage 2 DBPR information: