Statewide Well Test Results for Contaminants PFOA and PFOS Available Through Web-based Maps

SACRAMENTO October 15, 2019 – The State Water Resources Control Board posted the first results of testing for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) for nearly 600 drinking water supply wells, part of a comprehensive effort to assess the presence of these contaminants in water systems and groundwater statewide.

The results can be viewed on interactive maps on a user-friendly online portal that the State Water Board created for public reporting of the testing data.

Advertisement

In this first phase of testing, public water systems were ordered to sample drinking water supply wells near landfills or airports, locations where these chemicals are believed to be especially prevalent. They were also ordered to test wells near where the contaminants had been found previously.

PFOA and PFOS are chemicals that have been used in numerous industrial and consumer applications, from flame retardant foams commonly used at airports to water-repellent coatings for outdoor apparel, many of which were likely to have been discarded in landfills. These chemicals are particularly concerning because they don’t readily break down in the environment and have been found to accumulate over time in the human body.

In August, as the sampling was underway but complete results from the initial testing had yet to come in, the State Water Board lowered the notification level (NL) – the non-regulatory standard for requiring notification and further monitoring – from 14 parts per trillion (ppt) to 5.1 ppt for PFOA and from 13 ppt to 6.5 ppt for PFOS.

The new guidelines are based on updated health recommendations by the California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA). Notification levels are a nonregulatory, precautionary health-based measure for concentrations in drinking water that warrant notification and further monitoring and assessment.

Public water systems are encouraged to test their water for contaminants with notification levels. In some circumstance, they may be ordered to test. If the systems do test voluntarily, they are required to report exceedances of the NL to their governing boards and the State Water Board. They are also urged to report this information to customers.

While results from the initial testing were coming in, the State Water Board has kept the response level (RL) – the non-regulatory standard for recommending that a drinking water supply well be taken out of service – at 70 ppt for the combined concentration of both contaminants. An updated response level will be announced this fall.

Water systems have several options for reducing levels of contaminants in water supplies to below the notification or response levels: they can treat the water, blend it with water from another source, or take the supply well out of service. The State Water Board’s online maps show whether a water system is taking any of these actions to reduce levels of PFOA and PFOS.

While water consumers may find the test results daunting or confusing in some cases, the public is cautioned to put the findings in perspective. The notification level is set very conservatively – in the parts per trillion – as the State Water Board assesses the extent of these contaminants in drinking water and the degree to which they may cause adverse health effects.

To that end, the State Water Board has already requested that OEHHA develop public health goals (PHGs) for both PFOA and PFOS, the next step in the process of establishing regulatory standards, known as maximum contaminant levels (MCLs), in drinking water.

Meanwhile, the State Water Board will gather more test data in the weeks and months to come, presenting it on the same web interface unveiled today to the public. The order requires ongoing, quarterly testing of these 600-plus supply wells and that data will be compiled on the web portal and presented on the interactive maps in the coming months. Subsequent phases of this comprehensive look into PFOA and PFAS will include groundwater testing as well as incorporating existing test data acquired from numerous federal facilities – particularly military bases throughout California.

This new tool, created over several months by a team of engineers, scientists and other staffers within the Division of Drinking Water, gives stakeholders, the media and the general public an opportunity to view the findings on four maps offering an escalating degree of detail and complexity. It’s all part of the State Water Board’s commitment to be thorough and transparent during this process.

Assembly Bill 756 (Cristina Garcia, Chapter 162, Statutes of 2019) authorizes the State Water Board to more broadly order water systems to monitor for PFAS and report their detections. Additionally, the law requires that drinking water sources with PFAS levels that exceed the response level are either to be taken out of service or the water system must provide public notice of the exceedance level. The law takes effect January 1, 2020.

For more information, please visit our resources page on these contaminants. Readers can
find a frequently asked questions document, as well as a fact sheet that discusses ongoing
efforts to add additional data to the interactive, dynamic web portal.