CA PFAS Pollution Widespread in Disadvantaged Communities

NRDC’s new analysis of California’s drinking water testing for toxic, “forever” chemicals known as PFAS reveals widespread PFAS pollution in the state, particularly in communities that are already overburdened by multiple sources of pollution. Our report, developed in collaboration with Community Water Center, Physicians for Social Responsibility – Los Angeles, and Clean Water Action, also shows that much more testing needs to be done to fully understand the full scope of the PFAS problem.

PFAS (per- and polyfluoroalkyl substances) are a class of thousands of extremely persistent chemicals that accumulate in the environment and living organisms. The use of PFAS in numerous consumer and industrial applications has led to widespread human exposure and environmental contamination. A broad range of adverse health outcomes have been linked to PFAS exposure, including kidney and testicular cancer, elevated cholesterol, liver disease, decreased fertility, thyroid problems, changes in hormone functioning, changes in the immune system, and adverse developmental effects.

In April 2019, California’s Division of Drinking Water issued an order to test public water systems located near potential PFAS sources for PFAS. In our report, we analyzed test results from April 1, 2019, to June 30, 2020, in which more than 1,300 drinking water sources from 248 active public water systems in California were tested for 18 different PFAS chemicals.

PFAS pollution is widespread in California

Out of the 248 active public water systems that were tested, 65% had PFAS detected in the drinking water. These polluted water systems serve more than 16 million people in total. The water systems are spread across the state, and many serve cities with large populations. For instance, the water systems serving Fresno, Corona, and San Diego, have some of the highest total PFAS result, and these three systems serve almost 2 million people (see Map 1 below).

Map 1 - Potential Exposure to PFAS in California Drinking Water by Census Tract: The highest result (sum of 18 PFAS tested) for a source in each water system was assigned to each of the census tracts within a water system’s service area. This represents the highest potential exposure, or worst-case scenario, for each water system. The PFAS levels are divided into non-detects (0) and terciles for levels of PFAS detected, where each tercile contains an equal number of census tracts, ranked from low to high total PFAS results.


PFAS pollution is more intense in communities with preexisting environmental burdens

California has identified disadvantaged communities that are disproportionately burdened by and vulnerable to multiple sources of pollution through CalEnviroScreen, a CalEPA screening methodology. These communities face pollution burdens like air pollution, high pesticide use, and contaminated drinking water, which correlate to health complications such as asthma and cardiovascular disease. Additionally, these disadvantaged communities struggle with socioeconomic issues such as higher levels of poverty and unemployment than the rest of the state. Our study has found that the same disadvantaged communities that are affected by previously tested pollutants are often also affected by PFAS pollution (see Map 2 below). 69% of these communities had PFAS detected in their water system, and at least 20% of these tested communities were in the top quartile of PFAS levels in the entire state.

Map 2 - CalEnviroScreen 3.0 Scores and Potential Exposure to Total PFAS: The summed PFAS results are divided into terciles, where each tercile contains an equal number of census tracts. The CES percentile scores are divided into terciles from low to high pollution burden: 0 to 32 percent, 33 to 66 percent, and 67 to 100 percent. The census tracts that have both summed PFAS results higher than 57.2 parts per trillion (top tercile) and a CES percentile score higher than 66 percent are identified as the communities with the greatest overlapping burden; they are the most disproportionately burdened according to CES and potentially have the highest exposure to PFAS.


More testing needs to be done to fully understand the PFAS problem

While the testing to date covers half the population, it still represents only 3% (248 out of 7,896) of public water systems in California. Many small public water systems and domestic (private) wells are not covered under the State’s current monitoring program. This lack of testing means that more than 19 million Californians’ water has yet to be tested for PFAS. Furthermore, many rural and disadvantaged communities rely on small water systems or domestic wells, which already struggle to address other drinking water contaminants. With so many communities left unmonitored, the magnitude of PFAS pollution in the state is likely far greater than current data indicates.

In addition, California currently only tests for 18 PFAS chemicals, and only three of those—PFOA, PFOS, and PFBS—have established health advisories known as notification levels (these levels were exceeded in 44% of public water systems tested). Yet there are thousands of chemicals in the PFAS class, with hundreds known to be in active commercial use. With so many PFAS chemicals unaccounted for, we cannot know the true extent of PFAS pollution and associated harms.

What can be done?

Even with current testing limitations, the data clearly shows action must be taken to prevent further PFAS pollution and protect Californians from PFAS exposure and harms. The state must take steps to ensure that all Californians have access to clean water by taking comprehensive action to address this environmental and public health crisis, including:

  • improving monitoring and testing for PFAS,
  • cleaning up contaminated water,
  • providing clean water to disadvantaged communities in the interim, 
  • eliminating nonessential uses of PFAS in products and applications, and
  • ensuring safe disposal of PFAS waste.

For more detail on these policy interventions, see the report.

About the Authors

Anna Reade

Senior Scientist, Healthy People & Thriving Communities Program

Susan Lee

Data Analysis and Visualization Specialist, Science Office
Blog Post

The estimated number of Californians affected by water contaminated by toxic PFAS chemicals is rising. Data released just last week confirms that California has cause for worry, and underscores that the state should act now to protect its residents. Here we summarize state level solutions needed to address this widespread and growing public health and environmental problem.

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