Frequent Questions

Should results from the Initial Distribution System Evaluation (IDSE) standard monitoring required under the Stage 2 Disinfectants and Disinfection Byproducts Rule (DBPR) be used to determine compliance with maximum contaminant levels (MCLs) of the Stage

Results from the IDSE standard monitoring should not be used to determine compliance with the MCLs of the Stage 1 DBPR rule (71 FR 388, 419-420; January 4, 2006).

Additional information on IDSE monitoring is available in the Initial Distribution System Evaluation Guidance Manual (EPA815-B-06-002, January 2006) located online at http://water.epa.gov/lawsregs/rulesregs/sdwa/stage2/compliance_idse.cfm.
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