On July 18, the New Hampshire Department of Environmental Services (NHDES) adopted the strictest enforceable drinking water and groundwater quality standards for PFAS in the nation, finalizing the requirements at lower levels than and just six months after they were proposed. The final rule establishes Maximum Contaminant Levels (MCL) and Ambient Groundwater Quality Standards for four PFAS:
- PFOA at 12 parts per trillion (ppt)
- PFOS at 15 ppt
- PFHxS at 18 ppt
- PFNA at 11 ppt
NHDES evaluated the extent of PFAS contamination in the state, the ability to detect PFAS in public water systems, the ability to remove PFAS from drinking water, and costs and benefits to affected parties from the development of the standards. The rules underwent public comment and NHDES filed a final rulemaking proposal in June. The standards will become effective October 1 and will require local water systems to immediately begin sampling for PFAS quarterly in water used for consumption or for discharge into the ground.