On April 10, the U.S. Environmental Protection Agency (EPA) announced a final National Primary Drinking Water Regulation (NPDWR), establishing Maximum Contaminant Levels (MCLs) for six per- and polyfluoroalkyl substances (PFAS). The long-awaited regulation has drawn pushback from the water sector over the cost increases it may impose on utilities and ratepayers.
The final rule will regulate PFOA and PFOS to MCLs of 4 parts per trillion (ppt). It will also regulate PFHxS, PFNA, GenX to 10 ppt and will mandate water systems to measure for a mixture of at least two of the four chemicals PFHxS, PFNA, GenX and PFBS using a hazard index. The final NPDWR requires:
- Public water systems must monitor for these PFAS and have three years to complete initial monitoring (by 2027), followed by ongoing compliance monitoring. Water systems must also provide the public with information on the levels of these PFAS in their drinking water beginning in 2027.
- Public water systems have five years (by 2029) to implement solutions that reduce these PFAS if monitoring shows that drinking water levels exceed these MCLs.
- Beginning in five years (2029), public water systems that have PFAS in drinking water which violates one or more of these MCLs must take action to reduce levels of these PFAS in their drinking water and must provide notification to the public of the violation.
WATER FINANCE & MANAGEMENT
BY ANDREW FARR
APRIL 11, 2024