Two major U.S. water associations say they want a court to verify whether the Environmental Protection Agency (EPA) constructed its PFAS regulation according to the “letter and spirit” of the Safe Drinking Water Act.
Further analysis of the PFAS threshold would also give the EPA an opportunity to revisit any components of the rule that “fell short”, according to the American Water Works Association and the Association of Metropolitan Water Agencies, which filed the legal action earlier in June with the U.S. Court of Appeals for the District of Columbia Circuit to review.
At the heart of the complaint is the EPA’s use of a novel “hazard index” in place of a maximum contaminant level (MCL) for mixtures of certain PFAS, as well as the issuing of a preliminary determination to regulate certain PFAS simultaneously with the proposed rule.
While the groups say they are supportive of developing regulatory standards in this instance, both actions also vastly underestimate the nationwide costs of PFAS compliance, while failing to achieve the desired public health outcomes, the groups stated.
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“Scientific process matters, especially when it will set precedent for how EPA develops future drinking water regulations,” the associations announced in a June 7 joint statement that speaks to the alleged flaws in the EPA’s underlying analyses.
On April 26, the EPA published the national primary drinking water regulation for PFAS, which includes drinking water standards for six PFAS and establishes monitoring and public notification requirements for water systems. The agency ultimately maintained its proposal of 4 parts per trillion, or nanograms per litre, for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), the lowest concentration most laboratories can reliably detect.
However, the EPA also set a non-enforceable health-based goal, or maximum contaminant level goal, of zero.
The associations warn that the Safe Drinking Water Act does not give the EPA authority to use a hazard index as an MCL.
“The hazard index for the mixture of four PFAS in the new rule is a novel approach where the MCL is based on a sum of the ratios of four observed PFAS concentrations and each PFAS’s respective ‘health-based water concentration,’” the AWWA states.
The AWWA continues that the EPA should “consider withdrawing and re-proposing” drinking water standards for PFOA and PFOS given the “recurring issues” with the underlying analyses. It says that if the agency should finalize drinking water standards for PFOA and PFOS based on the current proposal, drinking water standards of 10 ppt, each, would be more appropriate.
When it comes to the financial cost of treating PFAS in drinking water, the groups suggest that the actual annualized national cost of adhering to the new EPA rule would be three times higher than the agency’s estimate of $1.5 billion.
The cost estimate is based on PFAS removal technologies such as granular activated carbon filtration, ion exchange filtration, and membrane filtration.
