In June 2019, the New Hampshire Department of Environmental Services (NH DES) proposed establishing a maximum contaminant level (MCL) for PFAS. If established, for NH public water suppliers the MCL would be 12 parts per trillion (ppt) for PFOA, 15 ppt for PFOS, 18 ppt for PFHxS and 11 ppt for PFNA.
For reference, the United State Environmental Protection Agency (US EPA) previously established a non-enforceable level of 70 ppt for PFOA and PFOS individually or combined. The limits being proposed by NH are more conservative than the current recommendation of the US EPA since research into the effects of these contaminants is on-going.
PFAS stands for Per- and Polyfluoroalkyl Substances which are actually a group of different chemicals. The substances proposed to be regulated in NH are four of the PFAS known as perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorononanoic acid (PFNA) and perfluorohexanesulfonic acid (PFHxS).
PFAS were specifically developed to repel other substances and to last a long time. This had advantages for the products in which it was used such as coatings for cookware, food packaging (ie. microwave popcorn bags and pizza boxes), clothing and carpets and firefighting foam. The problem is that PFAS have entered the environment and are now in water supply sources where they are doing what they were designed to do, lasting a long time and being resistant to removal using conventional water treatment techniques.
Studies are still ongoing into the health impacts of the various PFAS and these studies take time. There are numerous PFAS and each can have a different health impact on people. The results of studies are used to help establish maximum contaminant levels (MCLs) for PFAS in drinking water. MCLs are based on the health impacts of the contaminants, how widespread the contaminant is and the ability to remove the contaminant from water supply.
What’s next for NH? The proposal will be considered by the NH Joint Legislative Committee on Administrative Rules in July and if approved would become effective October 1, 2019.
NH DES PFAS Investigation information:
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