Earlier in 2025, NHDES adopted revised regulations that include PFAS criteria for surface water for New Hampshire. The revised regulations, Env-Wq-1700, were adopted and effective on February 25, 2025.
These changes are not yet highlighted on the NHDES Surface Water Quality Standards webpage or the PFAS Response webpage but the revised regulations are available here. The newly adopted regulations include water quality standards for surface water that is a source of drinking water or is “within 20 miles upstream of an active surface water intake” for drinking water for additional constituents since the most recent adopted rules in 2016. The newly adopted water quality standards are the maximum contaminant levels (MCLs) promulgated in Env-DW-700 apply as surface water standards for the water and fish ingestion human health criteria. The list of the compounds with MCLs that now have corresponding surface water standards can be found in Env-Wq-1703.21(l).
The four PFAS with NH MCLs (PFOA, PFOS, PFNA, and PFHxS) are included on this list of compounds with MCL values for water and fish ingestion criteria, whereas prior to this change, there were not NH surface water standards for PFAS. Further, there are other compounds that now have drinking water MCL-based surface water quality standards included in Env-Wq-1700 whereas previously standards had not been promulgated, such as cis-1,2-dichloroethylene, methyl tert-butyl ether (MTBE), styrene, total xylenes and others (see Table 1703-01 in Env-Wq-1703.21).
This change has significance for any site with Groundwater Management Permits (GMPs) and Release Detection Permits (RDPs) that include surface water sampling in surface water features that are being used for drinking water supplies. Further, this may also have considerations for NPDES permit renewals and compliance with general permit conditions.
Links:
Env-Wq 1700 Surface Water Quality Regulations
Posted In: Articles
Tagged In: New Hampshire, PFAS
