California Water Boards Release PFAS Assessment Data for Drinking Water Supplies

On October 14, 2019 the California State Water Resources Control Board released results from their first phase of their state-wide investigation into the presence of PFAS in groundwater. This initial phase of testing included almost 600 drinking water supply wells, primarily those in the vicinity of airports and municipal solid waste landfills, and in wells where these contaminants had been observed previously. Two subsequent phases are anticipated, which will include testing water supplies near manufacturing facilities and petroleum refining and storage facilities, recent urban wildfire areas, and wastewater treatment and pre-treatment plants.

When this testing began, the level of contamination that required notification was 14 parts per trillion for PFOA and 13 ppt for PFOS – two of the most widespread and understood PFAS chemicals. In August, the State Water Board lowered this level to 5.1 ppt and 6.5 ppt, respectively, based on updated health recommendations from the California Environmental Protection Agency. The initial results from the recent testing indicate that more than 200 of the tested water systems contained PFOA or PFOS in excess of the new notification levels, with 23 of those at levels where treatment or removing the drinking water source from production was recommended. All of the drinking water supply wells are to be tested quarterly throughout the year, with results presented regularly on the Water Board’s new portal.

To review the recent results and to find out more about California’s response to PFAS, please click the link here for the Water Board’s PFAS web site,

About PFAS - A family of chemicals first developed in the 1940s and today are known to consist of nearly 5,000 individual compounds, used in a variety of commercial and industrial applications. These uses include food packaging, waterproof and stain resistant fabrics used in clothing, furniture, and carpeting, and a type of fire-fighting foam known as AFFF widely used at military bases, airports, and oil and gas facilities. Very little is known about the toxicity of these compounds, but there is evidence to indicate that exposure to very small amounts of some of these chemicals results in negative health effects including kidney damage, reproductive and developmental issues, and cancer. As so little is known about these chemicals, the regulations and approaches to assessing and cleaning up these chemicals are constantly changing. SLR has more than a decade of experience addressing PFAS issues around the globe. Please contact us with questions about the most recent information and approaches to solving PFAS issues.