PFAS: PFOA and PFOS

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are man-made chemicals that have been used in a variety of industrial and commercial products since the 1940s.  They are part of a larger group referred to as per-and polyfluoroalkyl substances (PFAS). Although most PFAS chemicals are no longer manufactured or used in the United States, other countries still make products that contain these chemicals, which may be imported into the United States.

According to the U.S. Environmental Protection Agency (EPA), “PFAS can be found in:

• Food packaged in PFAS-containing materials, processed with equipment that used PFAS, or grown in PFAS-contaminated soil or water.
• Commercial household products, including stain- and water-repellent fabrics, nonstick products (e.g., Teflon), polishes, waxes, paints, cleaning products, and fire-fighting foams (a major source of groundwater contamination at airports and military bases where firefighting training occurs).
• Workplace, including production facilities or industries (e.g., chrome plating, electronics manufacturing, or oil recovery) that use PFAS.
• Drinking water, typically localized and associated with a specific facility (e.g., manufacturer, landfill, wastewater treatment plant, firefighter training facility).
• Living organisms, including fish, animals, and humans, where PFAS have the ability to build up and persist over time.”

For more information, visit EPA’s website at https://www.epa.gov/pfas/basic-information-pfas#exposed.

The EPA collects data for potential contaminants that may be present in drinking water under its Unregulated Contaminant Monitoring program.  These data have historically been used by EPA as a primary source of information to make regulatory decisions.  In 2012, EPA implemented its third Unregulated Contaminant Monitoring Rule (UCMR3), which included testing for PFAS contaminants.

From 2013 through 2015, the Orange County Water District (OCWD) performed UCMR3 testing for Orange County groundwater retail agencies.  YLWD is one of five water agencies in OCWD’s service area that found detections of PFOA and PFOS.

Groundwater is pumped out of the Orange County Groundwater Basin, which is managed by the Orange County Water District (OCWD).  OCWD has been working to identify potential sources of PFAS.  To date, OCWD has determined that neither water produced by its Groundwater Replenishment System (GWRS) project nor imported water purchased from the Metropolitan Water District (MWD) are a source of PFAS to the groundwater basin.  Testing of Santa Ana River surface water has revealed the presence of PFAS, including PFOA and PFOS.  For more information, visit OCWD’s website at https://www.ocwd.com/what-we-do/water-quality/.

The EPA provides health advisories as guidance for determining if concentrations of unregulated chemicals in drinking water are safe for public consumption.  Health advisories are non-enforceable and non-regulatory.

In May 2016, the EPA issued a new health advisory level of 70 parts per trillion (ppt) for the sum of PFOA and PFOS concentrations.  This health advisory level is based on a lifetime of exposure to PFOA and PFOS.  One part-per-trillion or one nanogram per liter is the equivalent of one grain of sand in an Olympic-sized swimming pool.  For more information, visit EPA’s website at https://www.epa.gov/ground-water-and-drinking-water/drinking-water-health-advisories-pfoa-and-pfos.

CLICK HERE FOR THE EPA’s ACTION PLAN 

The EPA and the State of California have established procedures for developing drinking water standards, also known as Maximum Contaminant Levels, or MCLs.  An MCL is the highest level of a contaminant allowed in drinking water and is considered safe for long-term consumption.  When a new unregulated contaminant is found, the state and federal agencies determine if it warrants regulation.  They may conduct studies on toxicology, occurrence, treatment, environmental fate and transport, and other factors.  After a thorough analysis of the facts, an MCL may be proposed and enacted.  To date, MCLs have not been established for the PFAS chemicals.

In July 2018, the State Water Resources Control Board (SWRCB) Division of Drinking Water (DDW) established Notification Levels for PFOA and PFOS at 14 ppt and 13 ppt, respectively.  Notification Levels are precautionary health-based advisory levels established by DDW while further research and analysis are conducted by the State and EPA to determine the necessity of setting enforceable drinking water MCLs and what the levels should be.  The Notification Levels are based on the most sensitive known health endpoints for these compounds: lifetime cancer risk, liver toxicity, and immunotoxicity. For more information, visit SWRCB’s website at https://www.waterboards.ca.gov/pfas/.

Treatment systems that remove PFOA and PFOS from water include activated carbon filters, ion exchange resins, and reverse osmosis membranes.

The Yorba Linda Water District has been proactive in addressing PFAS since learning about these compounds in our water.  YLWD has:

• Provided PFAS test results to our customers in YLWD’s annual Water Quality Reports even though not required; 
• Conducted frequent testing and monitoring of these contaminants since the EPA health advisory of May 2016;
• Developed a blending strategy to reduce concentrations of PFOA and PFOS in water delivered to our customers;
• Participated in technical meetings and met with experts on treatment technologies;
• Developed plans if concentrations exceed the federal or state standards;
• Worked as part of wide-ranging teams in the Orange County area to share the latest regulatory and test information and to identify the source of the PFAS.