Drinking Water

Setting maximum contaminant levels (MCLs) and sampling public and private water supplies.

Studies have shown that chronic or repeated ingestion of water with certain PFAS over a person’s lifetime may be associated with increased cholesterol and liver enzyme levels, as well as disorders of the cardiovascular, immunological, developmental and reproductive systems. Some scientific evidence suggests that certain PFAS, such as PFOA, may increase the risk of kidney and testicular cancer. According to the CDC’s Agency for Toxic Substances and Disease Registry (ATSDR), skin contact with PFAS in well water is not a major concern for exposure in most residential situations. This means washing and bathing are not expected to pose a known risk to human health. Additional information on health effects is available in the 2019 NHDES Technical Report, as well as from the Agency for Toxic Substances and Disease Registry.

Health standards

State law enacted in 2018 directed the New Hampshire Department of Environmental Services (NHDES), in consultation with the New Hampshire Department of Health and Human Services (NHDHHS), to set drinking water standards/maximum contaminant levels (MCLs) that are protective of human health for perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS) and perfluorononanoic acid (PFNA). These four compounds were selected because they have the greatest number of scientifically peer-reviewed studies and are found in New Hampshire. In July 2020, New Hampshire House Bill 1264 was signed into law establishing the following MCLs in nanograms/liter (parts per trillion or ppt):

  • Perfluorooctanoic acid (PFOA) – 12 ppt
  • Perfluorooctane sulfonic acid (PFOS) – 15 ppt
  • Perfluorohexane sulfonic acid (PFHxS) – 18 ppt
  • Perfluorononanoic acid (PFNA) – 11 ppt