DEQ outlines PFAS presence, monitoring timeline for Idaho drinking water; formal rule vote deferred

The Idaho Senate Health and Welfare Committee heard a presentation on per- and polyfluoroalkyl substances (PFAS) in drinking water from Tyler Fortunati, chief of the Drinking Water Bureau at the Idaho Department of Environmental Quality (DEQ). Fortunati described federal requirements, statewide sampling results, treatment costs at an affected Air Force base and funding options for public water systems. The committee did not vote on the related rule at this meeting; the chair said the vote would take place at a later date.

Fortunati told the committee that EPA finalized a drinking-water rule in April 2024 that sets maximum contaminant levels (MCLs) for six PFAS analytes at parts per trillion. Under that federal rule, public water systems must complete initial monitoring by April 2027, which will determine routine monitoring frequency beginning May 2027; consumer confidence report reporting begins in April 2027; public notification is required beginning in 2029 if a system exceeds an MCL; and compliance with the MCL is required by April 2029.

Why it matters: PFAS are persistent, can transport through air and water, bioaccumulate and are linked in some studies to human health effects, including an increased risk of certain cancers. The federal MCLs are extremely low (parts-per-trillion levels), which will…