California finds itself once again taking the lead by setting regulatory standards stricter than the rest of the nation. At issue is the nearly ubiquitous presence of certain PFAS chemicals in drinking water, a problem being addressed to varying degrees by many states and federal regulators. On Feb. 6, the California State Water Resources Control Board (SWRCB) lowered its reporting levels to below the thresholds set by the U.S. Environmental Protection Agency (EPA), requiring water agencies in California to take action earlier than water agencies anywhere else in the country.

The PFAS family of chemicals are synthetic organic compounds known for their resistance to stains and heat and their nonstick, waterproof qualities. These qualities have led to PFAS chemicals being used in innumerable applications, from fast food wrappers to stain-resistant fabric and carpet to firefighting foam. Unfortunately, the same qualities that make PFAS chemicals so useful also cause them to persist in the environment, accumulating in soil and groundwater without degrading for decades.

Some regulators have expressed concern that long-term or excessive exposure to PFAS chemicals may have adverse health consequences to those who are exposed. While the EPA has been studying health risks of PFAS chemicals for years, studies assessing long-term health effects of exposure to PFAS chemicals remain limited. To date, no legitimate toxicological or epidemiological studies have established association, let alone causation, between PFAS exposure and a particular adverse health effect. What is known is that exposure in the U.S. population is widespread, with one study detecting PFOS, a commonly used PFAS chemical, in the blood of 99% of the population.

So far, regulation has focused primarily on PFOS (perfluorooctane sulfonate) and PFOA (perfluorooctanoic acid), though health officials have warned that less common PFAS chemicals, including PFHxS, PFNA, PFHpA and PFDA, may pose similar health risks since they have close similarities to the more common PFAS chemicals. In 2016, the EPA set a "health advisory" level of 70 parts per trillion (ppt) for PFOS and PFOA, which required municipalities to notify their customers when testing of their drinking-water sources produced results exceeding these levels. However, the EPA has not yet set a national maximum contaminant level (MCL) under the Safe Drinking Water Act, which would require remediation of the drinking-water source if the level is exceeded.

Pursuant to the recently enacted National Defense Authorization Act for Fiscal Year 2020 (NDAA), on Jan. 1, 160 PFAS chemicals were added to the list of chemicals covered by the Toxics Release Inventory. Reporting on 2020 data for these chemicals will now be due to the EPA no later than July 1, 2021. The NDAA had the additional effect of forcing the EPA to accelerate elements of its 2019 PFAS action plan and require monitoring under the Safe Drinking Water Act. Some have viewed the EPA as being too slow to act, with House Democrats criticizing the EPA for failing to meet its own end-of-2019 deadline for deciding on a drinking-water standard for PFOA and PFOS.

Against this backdrop, California has been taking its own steps to increase attention to the problem of PFAS chemicals in its drinking water. Shortly after establishing the nation's strictest notice levels (NLs) for PFAS substances in drinking water, the SWRCB announced on Feb. 6, that it has also lowered its response levels (RLs) for additional compounds that fall within the PFAS rubric. The agency dropped the RL for PFOA from 70 ppt to 10 ppt, and dropped the RL for PFOS from 70 ppt to 40 ppt. These new RLs and NLs are based on updated health recommendations from the California Environmental Protection Agency's Office of Environmental Health Hazard Assessment (OEHHA) generated as part of the SWRCB's comprehensive investigation into PFOA and PFOS contamination in statewide water systems. The specific concentrations chosen for the RLs are also based on the limits of currently available, reliable testing technology. The SWRCB also announced that it was in the process of establishing MCLs for these chemicals, a step the EPA has still not undertaken.

When testing indicates the new RLs have been exceeded, the drinking-water provider must either provide treatment, take the water source out of service or notify its customers in writing. This is where things get tricky on multiple fronts. First, testing technology is still in a nascent stage compared to the technology used to test for other, long-regulated chemicals. Indeed, there are only 15 accredited testing labs in the entire country that employ the most current testing methods for PFAS chemicals. Second, while the current standards permit a water supplier to simply notify its customers of exceedances, rather than remediate, this may be a short-lived option since drinking-water customers are unlikely to accept water containing chemicals that they are increasingly hearing may have adverse health impacts; even though, again, there is currently no evidence that exposure to the microscopic concentrations of PFAS chemicals that trigger reporting can cause harm to even the most sensitive human populations. Third, when remediation is required, whether as a practical matter or by compulsion of new regulations, the available treatment methods are simply impracticable for the huge volumes of water municipalities process.

All of this increased regulatory attention on PFAS, as well as the ever-evolving state of scientific knowledge about the chemicals, will necessarily increase costs not only for businesses developing or using PFAS chemicals as they work on finding replacements for these very useful chemicals, but for wastewater treatment facilities and water utilities as they confront the challenges of developing effective testing regiments, cost-efficient remediation methods and in some cases alternative sources of water.

Jeffrey Dintzer and Peter Masaitis are partners at Alston & Bird in Los Angeles.