New US-EPA National Drinking Water Regulation for PFAS
The work on new limit values for drinking water in the US has been going on for a number of years. Last week (10 April) the US-EPA published the final National Primary Drinking Water Regulation (NPDWR) for PFAS. The regulation covers six PFAS: PFOA, PFOS, PFHxS, PFNA, GenX (HFPO-DA) and PFBS.
There are legally binding Maximum Contaminant Levels (MCL) for five of the six compounds and a Hazard Index (HI) for four (see table). The HI calculation is based on summation of the relative numbers obtained by division of the measured level by the health based water concentration for the substance. These health based concentrations are the same as the MCL for all but PFBS. The resulting sum should not exceed 1. In addition, there are Maximum Contaminant Level Goals (MCLG), a non-enforceable health-based goal, that are zero for PFOS and PFOA and the same as the MCL for the rest.
Overview NPDWR. MCL = maximum contaminant levels. ppt = parts per trillion » ng/l
Regarding implementation initial monitoring by public water suppliers should be completed by 2027. Thereafter the monitoring becomes compulsory and public information on the concentrations should be made available. In 2029 if the drinking water exceeds the MCLs action needs to be taken by the provider and the consumers notified. The cost for monitoring and treatment technologies has been estimated to 1.5 billion USD per year by the US-EPA.
If the new US-EPA limits are compared to EU regulation for drinking water it can be noted that the EFSA PFAS4 (PFOS, PFOA, PFHxS, PFNA) are covered. In Sweden and Denmark sum of PFAS4 limits of 4 and 2 ng/l have or will be implemented i.e. in the same low ng/l range as in the US (despite some differences in risk assessment). The Dutch guideline value of 4.4 ng/l PFOA equivalents is comparable too. GenX (or HFPO-DA) is a PFAS ether that has replaced PFOA in F-polymer production. In the US the compound has been the major contaminant in the Cape Fear river (N:th Carolina) case while in the EU it has above all been associated with emissions from the Chemour plant in Dordrecht (NL). The MCL for GenX (10 ppt) is lower than earlier estimates in both NL and US, but coincides with the Dutch guideline value for surface water from 2022 (RIVM).
Contact Eurofins experts!
Questions about PFAS can be answered by our analytical advisory service, which can be reached via customer support, 010-490 8110 or e-mail: sh-analys.miljo.se@etn.eurofins.com