New Hampshire Proposes New PFAS Drinking Water Standards and Initiates Rulemaking

NH DES logoOn December 31, the New Hampshire Department of Environmental Services (NHDES) initiated a rulemaking with their newly proposed drinking water Maximum Contaminant Levels (MCLs) and Ambient Groundwater Quality Standards (AGQS) for four per- and polyfluoroalkyl substances (PFAS) that are protective of health for the most sensitive populations over a lifetime (as shown in the following table).

PFAS Compound Proposed Level (ppt)
Sum of PFOA and PFOS 70
PFHxS 85

These MCLs are drinking water quality standards for non-transient public water systems and the AGQS are used to require remedial action and the provision of alternative drinking water at a contaminated site. The AGQS also dictates the conditions under which treated and untreated wastewater may be discharged to groundwater. Current law requires AGQSs be the same value as any MCL established by NHDES and that they be as stringent as health advisories set by EPA.

To develop these MCLs, NHDES had to address the extent to which the contaminant is found in New Hampshire, the ability to detect the contaminant in public water systems, the ability to remove the contaminant from drinking water, and the costs and benefits to affected parties that will result from establishing the standard, and then develop a MCL for each compound that is protective of the most sensitive population at all life stages.

The state will hold public hearings and accept public comments on the proposed PFAS MCLs through early March and expects to finalize the proposals by summer. The effective date of the new rules has yet to be determined. For more information, read the NHDES press release and associated Patch article.