Frequent Questions

If a system modifies its distribution system after completing its IDSE, is it required to complete a new IDSE?

No new IDSE report is required, but the system should work with its primacy agency to change its Stage 2 DBPR monitoring plan to address the changes to the distribution system.

For additional guidance on the Stage 2 Disinfectants and Disinfection Byproducts rule please visit

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