The American Water Works Association (AWWA) and the Association of Metropolitan Water Agencies (AMWA) filed a petition with the U.S. Court of Appeals for the District of Columbia Circuit to review the Final per-and polyfluoroalkyl substances (PFAS) Drinking Water Rule issued by the U.S. Environmental Protection Agency (USEPA).
In April, USEPA announced the first-ever national, legally enforceable drinking water standard to protect communities from exposure to PFAS. USEPA has established legally enforceable levels for several PFAS known to occur individually and as mixtures in drinking water. The rule sets limits for individual PFAS: PFOA, PFOS, PFNA, PFHxS, and HFPO-DA (also known as “GenX Chemicals”). The rule also sets a limit for mixtures of any two or more of four PFAS: PFNA, PFHxS, PFBS, and “GenX” chemicals.
- Enforceable Maximum Contaminant Levels (MCL) are set at 4.0 parts per trillion (ppt) for PFOA and PFOS, individually. The standard will reduce exposure in drinking water to the lowest levels that are feasible based on current analytical methods.
- The Maximum Contaminant Level Goal (MCLG) and MCL are set at 10 ppt for PFNA, PFHxS, and GenX Chemicals. An MCLG is a non-enforceable health-based goal. USEPA has deferred the final regulatory determination and standard setting for PFBS to allow for further evaluation.
- The MCLG for PFOA and PFOS is zero. USEPA says this reflects the latest science showing that there is no level of exposure to these contaminants without risk of health impacts, including certain cancers.
- Health Based Water Concentrations (HBWC) have been set at 10 ppt for PFNA, PFHxS, and GenX and 2,000 ppt for PFBS.
- As a novel concept, USEPA is setting a Hazard Index (HI) of 1 for any mixture of two or more of the following: PFNA, PFHxS, PFBS, and GenX Chemicals. The Hazard Index represents the sum of quotients calculated by dividing the analytical result for PFNA, PFHxS, PFBS, and GenX by the respective HBWC.
- Samples are collected from each entry point while compliance is determined based on a running annual average of samples.
AWWA CEO David LaFrance and AMWA CEO Tom Dobbins released the following statement regarding legal action related to USEPA’s Final National Primary Drinking Water Regulation (NPDWR) for PFAS: “The rule significantly underestimates nationwide costs, does not consider the latest PFAS data, and will add to affordability challenges for many households without achieving the public health outcomes we all seek. Scientific process matters, especially when it will set precedent for how EPA develops future drinking water regulations. AMWA and AWWA therefore believe it is prudent to ask a court to verify that EPA constructed the PFAS regulation according to the letter and spirit of the Safe Drinking Water Act, and to give EPA an opportunity to revisit any components of the rule that fell short.”
In April, USEPA said affected water systems, including community water systems and non-transient non-community water systems will have three years to complete the initial monitoring for the PFAS chemicals. Initial monitoring is based on system size and source water type. USEPA has extended the compliance deadline by two years for those systems requiring treatment, thus allowing water systems up to five years to come into compliance. The rule also requires public water systems to inform the public of the level of PFAS measured in their drinking water. If PFAS is found at levels that exceed the standards, systems must implement solutions to reduce PFAS in their drinking water within five years, by 2029.
If you have questions about how the new PFAS rule may affect your public water system, reach out to Nate Weisenburger, AE2S Drinking Water Practice Leader.