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Advancing PFAS Regulations: Federal and California Updates

July 31, 2000


Per- and polyfluoroalkyl substances (PFAS) are a family of thousands of chemicals that vary widely in their chemical and physical properties, as well as their potential risks to human health and the environment. Since the 1950s, many products commonly used by consumers and industry have been manufactured with or from PFAS. The unique physical and chemical properties of PFAS impart oil, water, stain, and soil repellency, chemical and thermal stability, and friction reduction to a range of products. These products have application in many industries, including the aerospace, semiconductor, medical, automotive, construction, electronics, and aviation industries, as well as in consumer products such as carpets, clothing, furniture, outdoor equipment, food packaging and firefighting applications. 

Occupational studies in the 1970s found detections of some PFAS in the blood of exposed workers and further studies in the 1990s reported detections in the blood of the general human population. In recent years, the presence of several long-chain Perfluoroalkyl Acids (PFAAs), including Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS) have been measured in the low parts per billion (ppb) range in the blood serum of almost all residents of the United States and other industrialized nations. 

At the Federal level, the United State Environmental Protection Agency (USEPA) developed a PFAS strategic roadmap that outlines USEPA’s approach to regulating PFAS. Because PFAS is in widespread use across the US, the USEPA focused not only on addressing the downstream impacts of PFAS pollution, but also upstream to prevent new PFAS contamination from entering the environment.  In California, the State Water Resources Control Board’s (SWRCB), Division of Drinking Water (DDW) has also taken action to regulate the amount of PFAS in drinking water. 

The purpose of the regulations is to protect public health and environment from the impacts of PFAS.  Industries that utilize and sell products containing PFAS, and owners of PFAS-contaminated properties should be aware of the advancing regulatory actions. 

United States Environmental Protection Agency Actions 

On January 8, 2009, the USEPA issued non-enforceable, provisional health advisory values for PFOA and PFOS of 0.4 ppb and 0.2 ppb to assess potential risk from exposure to these chemicals through drinking water. 

In May 2016, the USEPA issued drinking water health advisories for PFOA and PFOS to replace the provisional advisories.  The USEPA issued a non-enforceable lifetime health advisory of 70 parts per trillion (ppt), the equivalent of 0.070 ppb.  This lifetime health advisory was based on the USEPA’s latest external peer reviewed health effects information and is protective of the population at large. When both PFOA and PFOS are found in drinking water, the combined concentrations of PFOA and PFOS should be compared with the 70 ppt lifetime health advisory level. 

On June 15, 2022, the USEPA issued interim updated, non-enforceable drinking water health advisories for PFOA (0.004 ppt) and PFOS (0.02 ppt) that replace those issued in 2016. The USEPA also issued Final Health Advisories for perfluorobutane sulfonic acid and its potassium salt (PFBS, 2,000 ppt) and for hexafluoropropylene oxide (HFPO) dimer acid and its ammonium salt (“GenX” chemicals, 10 ppt). In chemical and product manufacturing, GenX chemicals are considered a replacement for PFOA and PFBS is considered a replacement for PFOS.  These interim health advisories will remain in place until EPA establishes a National Primary Drinking Water Regulation (NPDWR). 

On March 14, 2023, the USEPA announced the proposed NPDWR for six (6) PFAS including PFOA, PFOS, PFBS, GenX Chemicals, perfluorononanoic acid (PFNA) and perfluorohexane sulfonic acid (PFHxS) under the Safe Drinking Water Act. The proposed PFAS NPDWR does not require any actions until it is finalized. EPA anticipates finalizing the regulation by the end of 2023.  

The NPDWR would establish nationwide, legally enforceable drinking water Maximum Contaminant Levels (MCLs) which apply to public water systems for these six (6) PFAS compounds.  The proposed MCL for PFOA and PFOS are 4.0 ppt each. PFOA and PFOS are proposed for regulation as individual contaminants due to their likely carcinogenicity.  The remaining four PFAS chemicals, PFBS, GenX Chemicals, PFNA and PFHxS would be regulated using a Hazard Index (HI) tool used to evaluate potential health risks from exposure to chemical mixtures.  The USEPA has proposed Health Based Water Concentrations (HBWCs) for these four PFAS chemicals, which is the level below which no health effects are expected.  The measured concentrations of these PFAS chemicals in a drinking water source would be evaluated using the HBWCs and HI tool to arrive at an HI value. 

When finalized, the proposed PFAS NPDWR rule will require public water systems to: 

  • Monitor for these PFAS; 
  • Notify the public of the levels of these PFAS; and, 
  • Reduce the levels of these PFAS in drinking water if they exceed the proposed standards. 

Updates to the proposed PFAS NPDWR are posted at Per- and Polyfluoroalkyl Substances (PFAS) | US EPA

Environmental Due Diligence and PFAS 

As indicated by the continued evolution of potential acceptable levels of PFAS in groundwater that have been considered by the USEPA, the regulations are currently in a state of flux and the lack of clear guidance introduces uncertainty into the due diligence process.   

PFAS are not currently covered under the commonly used American Society for Testing and Materials (ASTM) Standard Practice for Environmental Site Assessments: Phase I Environmental Site Assessment Process (ASTM E 1527-21) because these chemicals are not currently classified as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA).  EPA has proposed to add two PFAS compounds, PFOA and PFOS to the list of CERCLA hazardous substances list, but the final action is not expected to take effect until February 2024.   

CERCLA designation will require inclusion of these PFAS chemicals in the scope of the ASTM Standard Practice for Environmental Site Assessments.  In the interim, parties conducting due diligence may want to request that the environmental professional include a PFAS evaluation as an add-on to the standard Phase I ESA scope of work.   

Updates to the proposed rule to designate PFAS as hazardous substances are posted at Advanced Notice of Proposed Rulemaking on Potential Future Designations of Per- and Polyfluoroalkyl Substances (PFAS) as CERCLA Hazardous Substances | US EPA.  

California Environmental Protection Agency (CalEPA) Actions 

In July 2018, the California SWRCB’s DDW established an interim Notification Level (NL) of 14 ppt for PFOA and 13 ppt for PFOS, and a single Response Level (RL) of 70 ppt for the combined concentrations of PFOA and PFOS. NLs are nonregulatory, health-based advisory levels established for contaminants in drinking water for which MCLs have not been established.  

NLs are developed and issued by the DDW based on recommendations made by the Office of Environmental Health and Hazard Assessment (OEHHA). RLs are set higher than a notification level and represents a recommended chemical concentration level at which water systems consider taking a water source out of service or provide treatment if that option is available to them. 

Since 2018, the DDW has issued several revisions and updates to PFAS NLs and RLs, and released draft Public Health Goals (PHGs). 

  • In August 2019, DDW revised the NLs to 5.1 ppt for PFOA and 6.5 ppt for PFOS. The single Health Advisory Level (for the combined values of PFOA and PFOS) remained at 70 ppt. 
  • On February 6, 2020, DDW issued updated drinking water RLs of 10 ppt for PFOA and 40 ppt for PFOS based on a running four-quarter average. 
  • On March 5, 2021, DDW issued a drinking water NL and RL of 0.5 ppb and 5 ppb, respectively for PFBS. 
  • On July 22, 2021, OEHHA released draft PHGs for PFOA and PFOS. PHGs are established by OEHHA and are concentrations of drinking water contaminants that pose no significant health risk, based on current risk assessment principles, practices, and methods. PHGs serve as the basis for the development of MCLs. 
  • On October 31, 2022, DDW issued a drinking water NL and RL of 3 ppt and 20 ppt, respectively for PFHxS.   

Over the past few years, the DDW has also issued several general monitoring orders to public water systems in California, including General Orders 2020-0003-DDW (rescinded), DW-2021-0001-DDW (rescinded), and DW-2022-0001-DDW. If monitoring results in a confirmed detection, then a water system is required to report that detection in the annual Consumer Confidence Report.   

As of August 2023, MCLs for PFAS in California have not yet been established. The development of standards for PFOA, PFOS, and other PFAS are among the priorities of the DDW.   

Updates to the upcoming rulemaking process for PFOA and PFOS in California will be posted at SWRCB-DDW-24-001 PFOS/PFOA MCL | California State Water Resources Control Board

How VERTEX Can Help

The Vertex Companies, LLC (VERTEX), with an extensive staff of professional engineers, professional geologists, environmental scientists, and remediation specialists, can provide assistance with PFAS-related contamination issues, including due diligence investigations, investigation of impacts to the environment, evaluation of laboratory analytical data and associated regulatory requirements, and the selection and implementation of an appropriate mitigation/remediation approach based on site-specific impacts and geologic/hydrogeologic settings. VERTEX can also assist insurance carriers with the evaluation of PFAS-related claims made on pollution insurance policies.  

For more information, contact Steve Long at or (303) 623-9116. 

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