The New Hampshire Department of Environmental Services (NHDES) recently initiated a rulemaking to establish maximum contaminant levels (MCLs) and ambient groundwater quality standards (AGQS) for four PFAS substances. The proposed levels are 38 parts per trillion (ppt) for perfluorooctanoic acid (PFOA), 70 ppt for perflurooctanesulfonic acid (PFOS), 70 ppt for PFOA and PFOS combined, 23 ppt for perflurononanoic acid (PFNA), and 85 ppt for perfluorohexanesulfonic acid (PFHxS).
These MCLs represent drinking water quality standards with which non-transient public water systems must comply. AGQSs are standards used to require remedial action and the provision of alternative drinking water at a contaminated site, and dictate how contaminated water is treated or discharged to groundwater. New Hampshire law requires AGQSs be the same value as MCLs and be as stringent as health advisories set by U.S. EPA. In 2016, EPA set a lifetime health advisory of 70 ppt for PFOA and PFOS in drinking water.
NHDES will host public hearings and open a comment period on the proposed MCLs. The agency anticipates the finalized by summer. See the press release here. See the summary report on how NHDES developed the values here. [Poole]