New York’s drinking water standards for emerging contaminants are among the most stringent in the country, including standards issued in 2020 for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) at concentrations of 10 parts per trillion (ppt).  See N.Y. Comp. Codes R. & Regs. tit. 10, Section 5-1.52.  Consequently, it should come as no surprise that, earlier this month, the New York State Department of Health (NYSDOH) published a proposed rulemaking seeking to adopt drinking water Maximum Contaminant Levels (MCLs) for four additional per- and polyfluoroalkyl substances (PFAS).  MCLs are drinking water standards that set the highest level of a contaminant that is allowed in drinking water.

The proposed rule, published in the New York Register, includes MCLs of 10 ppt for perfluorodecanoic acid (PFDA), perfluoroheptanoic acid (PFHpA), perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA).  

In addition, the rule would establish a combined MCL of 30 ppt for what is collectively referred to as perfluoroalkyl substances-6 (PFAS6), which includes PFDA, PFHpA, PFHxS, PFNA, PFOA, and PFOS.  

Any comments to the proposed rulemaking must be submitted by December 5, 2022, to Katherine Ceroalo, DOH, Bureau of Program Counsel, Reg. Affairs Unit, Room 2438, ESP Tower Building, Albany, NY 12237, (518) 473-7488, email: