In support of the State Water Resources Control Board’s (State Board) efforts to investigate and evaluate the public health effects of per- and polyfluoroalkyl substances (PFAS), the San Francisco Regional Water Quality Control Board (Regional Board) has released interim final Environmental Screening Levels (ESLs) for two of the most prevalent PFAS compounds: perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA). The Regional Board, other environmental agencies, and private parties use ESLs to help identify and evaluate potential human health and ecological concerns at contaminated sites. Although these ESLs are not yet formally incorporated in the Regional Board’s policy documents, they provide key guidance regarding what levels of PFAS contamination will require investigation and, potentially, cleanup, going forward across the state. In an accompanying memorandum, the Regional Board also confirmed its regulatory approach for PFAS testing, investigation, and cleanup.

The Current Federal and State Regulatory Landscape for PFAS

PFAS are synthetic, human-made compounds that were manufactured in the United States beginning in the 1940s. Their ability to repel oil and water led to their widespread use in consumer products, such as non-stick pans, outdoor gear, raincoats, carpets and upholstery, and food packaging. PFAS compounds were also widely used in industrial processes, including chrome plating, electronics manufacturing, and firefighting foams.

As Farella discussed in a previous article, federal law currently does not regulate PFAS, either under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) or through other enforceable limits such as maximum contaminant levels (MCLs) in drinking water. However, the U.S. EPA has pledged to evaluate potential PFAS regulations, including designating certain compounds as “hazardous substances” under CERCLA, setting enforceable MCLs, and developing regulatory standards for PFOS and PFOA at cleanup sites.

In the meantime, California and other states have begun efforts to investigate and regulate PFAS contamination. In 2019, the State Board sent PFAS investigation orders to several types of priority facilities across the state (including commercial airports, municipal solid waste landfills, and chrome plating facilities), as well as hundreds of public water systems that are in proximity to such facilities and/or have had PFAS detections. The State Board intends to send similar orders to a number of other types of priority facilities (including oil refineries and bulk terminals and wastewater treatment plants) later in 2020.

The Regional Board’s New ESLs and Regulatory Approach to Test, Investigate, and Clean Up PFAS Contamination

To facilitate these PFAS investigations and complement the State Board’s work, the Regional Board on May 27 issued two memoranda: (1) a technical memorandum setting forth interim final ESLs for PFOS and PFOA, along with the scientific rationale for those ESLs, and (2) a transmittal memorandum, explaining the regulatory approach to be implemented by the Regional Board, using those ESLs. The Regional Board intends to formally incorporate the new ESLs in its next major ESL guidance update, tentatively set for 2021.

The new ESLs will become a key driver for assessment of sites with PFAS contamination, not only within the Regional Board’s jurisdiction, but across the state. ESLs are risk-based concentrations of chemicals against which environmental sampling data collected at contaminated sites can be compared. Generally, the Regional Board considers sites with concentrations below the relevant ESLs to not pose a significant threat to human health or the environment. Where ESLs are exceeded, the site may pose a significant threat, and further investigation is warranted (and often required) to assess the threat and determine whether cleanup is necessary or appropriate.  Although both regulatory agencies and private parties can use alternative approaches to assess human health and ecological risk, particularly where site-specific factors warrant it, ESLs are the most commonly used thresholds in California for making initial decisions about whether a site is deemed “contaminated” at a level requiring action.  For this reason, ESLs play an important role in a number of contexts, including due diligence for property acquisitions, use of groundwater as drinking water (in the absence of MCLs), and investigations by environmental regulatory agencies such as the Regional Board.

According to the transmittal memorandum, the Regional Board intends to use the new ESLs as part of a regulatory approach to PFAS testing, investigation, and cleanup that will initially focus on occurrence testing at priority sites within its jurisdiction that were not included in the State Board investigation orders. Although the Regional Board intends to “gradually” implement this approach as “time and resources allow,” the Board noted that it would prioritize testing based on current and historical use of PFAS and the potential to affect drinking water or aquatic receptors. Potential priority sites include current or former:

• Firefighting practice training areas;
• Semiconductor facilities;
• Electronics manufacturers;
• Former chrome plating facilities and non-chrome metal plating and finishing facilities;
• Mining industry (copper, gold, aluminum, vanadium, and uranium);
• Textile manufacturers and processors;
• Furniture manufacturers and upholsterers;
• Carpet manufacturers;
• Cardboard/paper packaging manufacturers;
• Surface coatings/paints/varnish manufacturers and high-volume users; and
• Manufacturers of known PFAS-containing products, such as dental floss, non-stick cookware, food packaging materials, waterproof textiles, medical garments, and personal care products.

Once identified, sites will be prioritized based on factors such as the “potential for spill or discharge to the environment and proximity or connection to drinking water or aquatic resources that could be affected.” Results of the occurrence testing will be compared with ESLs and used by the Regional Board to decide whether to require additional site investigation and/or cleanup.

Analysis and Conclusions

Although the Regional Board has not yet fully incorporated the interim final ESLs for PFOS and PFOA into its policy documents, they are a major step forward into the uncharted, but fast approaching, world of routine PFAS site assessment and cleanup. For sites where PFAS sampling has already been conducted, these ESLs offer an opportunity to proactively review and evaluate the regulatory risk associated with PFOS or PFOA levels, prior to receipt of any Regional Board or other regulatory directives, and to develop a strategy (and identify funding) for addressing any ESL exceedances. Alternatively, for those who have been hesitant to conduct testing due to the lack of regulatory guidance on how to evaluate the results, key guidance is now available.

Those considering new sampling for PFOS, PFOA, and other PFAS compounds that may be tied to a property or facility should also consider collecting background samples. The widespread use of PFAS may have resulted in local background levels of PFOS and PFOA similar to or higher than levels found at or near the property/facility at issue, even potentially above the ESLs. For example, the Regional Board noted in the technical memorandum that sampling in parts of San Francisco Bay found ambient concentrations of PFOS and PFOA above the relevant (aquatic habitat) ESLs. Background sampling can therefore assist in distinguishing site-specific contamination from contamination originating at other sources and potentially reduce one’s exposure to regulatory risk and investigation/cleanup costs. 

Because of their ubiquitous use and persistence in the environment, PFAS compounds have been detected in groundwater and surface water throughout California and the rest of the United States, and we expect that efforts to investigate and clean up PFAS will rapidly intensify. As a result of the Regional Board’s issuance of the new ESLs, property owners (and potential purchasers of property), in coordination with their legal counsel and technical consultants, are now in a better position to take meaningful steps to understand the potential risks and costs associated with PFAS contamination.