New Hampshire Adopts MCLs for Four PFAS

Yesterday (July 22, 2020), New Hampshire’s Governor signed into law an Omnibus bill that included MCLs for four PFAS compounds.  The four MCLs will go into effect in 2022 and are presented below.

  • PFOA: 12 parts per trillion (ppt)
  • PFOS: 15 ppt.
  • PFHxS: 18 ppt.
  • PFNA: 11 ppt.


On September 30, 2019 four PFAS MCLs adopted by the New Hampshire Department of Environmental Services went into effect.  That same day 3M, Plymouth Water and Sewer District, Resource Management Inc., and an individual filed a lawsuit requesting that the Court “declare invalid” the State’s PFAS standards.  On November 26, 2019, a judge in New Hampshire issued a preliminary injunction to halt implementation of the PFAS MCLs.  The injunction was based on the judge’s determination that the State had “not conducted an adequate cost-benefit analysis…”  The judge delayed his ruling until December 31, 2019 to allow either party to submit an appeal to the New Hampshire Supreme Court (“….the legal issues raised by the Plaintiffs’ challenge are complex, the importance of public health is paramount and the expense imposed by the proposed rule is significant”).   Meanwhile, during 2020 the New Hampshire House and Senate developed legislation addressing PFAS, including the four MCLs.