Vermont Governor Phil Scott signed into law on May 16, 2019, one of the most stringent limits in the country on the presence of perfluorinated alkylated substances (PFAS) in drinking water. The law, which was passed by the Vermont House and Senate in late April as S. 49, requires public water systems to monitor their water supplies in an effort to ensure that they do not exceed a combined limit of 20 parts per trillion (ppt) for five PFAS compounds:

1. Perfluorooctanoic acid (PFOA).
2. Perfluorooctane sulfonic acid (PFOS).
3. Perfluorohexane sulfonic acid (PFHxS).
4. Perfluorononanoic acid (PFNA).
5. Perfluoroheptanoic acid (PFHpA).

The law also directs the Secretary of Natural Resources to take additional steps to tighten controls over PFAS in Vermont water supplies.

Under the law, if any of the five regulated PFAS contaminants are present, individually or in combination, in a public waters system (PWS) in excess of 20 ppt, the PWS must:

1. Implement treatment or other measures to reduce the regulated PFAS contaminants to levels below the advisory level (20 ppt).
2. Issue a “do not drink” notice to all users of the public water system until the regulated PFAS contaminants are below the advisory level.

In addition, the law requires the Secretary of Natural Resources to:

1. Issue a final proposed rule establishing a maximum contaminant level (MCL) for the five regulated PFAS compounds.
2. Initiate a rulemaking process to solicit public comments regarding the potential regulation of a wider array of PFAS compounds as a class or sub-classes.
3. Undertake a rulemaking process for the adoption of surface water quality standards for PFAS compounds.
4. Publish a plan, subject to public review and comment, to complete a statewide investigation of potential sources of PFAS contamination.
5. Submit a report regarding the management at landfills of leachate containing contaminants of emerging concern (CECs), including recommendations for treatment of CECs in leachate from landfills.