Perfluoroalkyls and polyfluoroalkyls, commonly known as PFAS, are manmade chemicals widely used since the 1940s. PFAS has been used in various commercial and industrial applications, including carpeting, waterproof clothing, food paper wrappings, cookware, cosmetics, and firefighting foam.

While manufacturers no longer use several such chemicals, they have made their way into the environment over the years.  PFAS are frequently referred to as “forever chemicals,” as they do not naturally break down in the environment and can be found in the water, air, and soil. Due to their widespread use and resiliency, they are found worldwide.

Exposure to high levels of PFAS over a long period and during critical life stages, such as during pregnancy and early childhood development, may contribute to adverse health effects. Through treatment, levels of PFAS in drinking water can be reduced to meet applicable standards, which continue to evolve at both the federal and state level.

What is being done to protect drinking water?

Our highest priority is providing customers with safe and high quality drinking water. We routinely monitor and test water to ensure that the level of PFAS in your drinking water meets all federal and state water quality standards. When PFAS is detected at levels beyond the state’s notification level, Golden State must notify local government agencies and state water regulators.

Contaminants such as PFAS are also disclosed in our annual Consumer Confidence Report emailed to customers and posted on this website, listed explicitly by customer service area

Who pays for PFAS treatment?

Although PFAS manufacturers are responsible for creating this environmental issue, Golden State Water and its customers are burdened with the treatment cost. Golden State Water has instituted legal action against those it believes are responsible for creating the PFAS contamination. The expenses incurred to maintain water quality, including treatment and testing, are ultimately supported by the customers’ water bill rates.

In Golden State Water Company’s rates for 2023-24, the company is investing in water treatment facilities designed to meet today’s drinking standards as they evolve.

Your rates play a vital role in ensuring that our water systems continues to meet all federal and state quality standards established to protect public health and safety.


Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS) are fluorinated organic chemicals that have been used in the making of domestic products such as carpets, cookware and other products that are resistant to water, grease or stains. PFOA and PFOS have also been used for suppressing fires, primarily at airfields and military bases.

According to the U.S. Environmental Protection Agency (EPA), most people have been exposed to PFOA and PFOS because they are used in an array of consumer products. PFOS was voluntarily phased out of production by its primary manufacturer in the United States between 2000-2002, and eight other major companies voluntarily agreed to phase out their global production of PFOA-related chemicals in 2006. There remain a limited number of ongoing uses for the chemicals.

While consumer products and food are a large source of exposure to these chemicals for most people, drinking water can be an additional source in the small percentage of communities where these chemicals have infiltrated water supplies. Such contamination is typically localized and associated with a specific facility, such as an industrial facility where these chemicals were produced or used to manufacture other products or an airfield at which they were used for firefighting or wastewater treatment plants or landfills where products containing these chemicals were disposed of.

PFOA and PFOS are unregulated drinking water contaminants addressed in the EPA’s Unregulated Contaminant Monitoring Rule (UCMR3). In June 2022, the U.S. EPA issued interim updated drinking water health advisories (HAs) for PFOA and PFOS that replaced existing HAs. Learn more about HAs:

The EPA originally established this health advisory level in 2016 to offer a margin of protection from adverse health effects for a lifetime of exposure to PFOA and PFOS in drinking water at this level.

On Aug. 23, 2019, the California State Water Resources Control Board (SWRCB) updated state guidelines that lower the current notification levels to 5.1 parts per trillion (PPT) for PFOA and 6.5 PPT for PFOS. On Feb. 6, 2020, the SWRCB established new response levels of 10 PPT for PFOA and 40 PPT for PFOS.  On Mar. 5, 2021, the SWRCB established a response level of 500 PPT and notification level of 5,000 PPT for PFBS. On October 31, 2022, the SWRCB established a response level of 20 PPT and a notification level of 3 PPT for PFHxS.

Golden State Water routinely monitors and tests its water and proactively tracks state and federal regulations as they evolve. It is expected that EPA will propose Maximum Containment Levels (MCL) for PFOA and PFOS in the future.   

Additionally, water quality test results are directly submitted from a State-certified laboratory to DDW and recorded on the State’s website for full transparency. Click here to view test results on the DDW website. Golden State Water also makes water quality information available via the annual CCRs.

As your water provider, we continually invest in water infrastructure, treatment and testing and take great pride in providing you with high-quality, reliable water.

Frequently Asked Questions

Q:   Is EPA going to establish a national drinking water standard for PFOA and PFOS?
A:   Golden State Water expects the EPA to propose Maximum Containment Levels (MCLs) for PFOA and PFOS in the fall of 2022. The EPA continues to evaluate PFOA and PFOS as drinking water contaminants in accordance with the process required by the Safe Drinking Water Act (SDWA). To regulate a contaminant under SDWA, EPA must find that it: (1) may have adverse health effects; (2) occurs frequently (or there is a substantial likelihood that it occurs frequently) at levels of public health concern; and (3) there is a meaningful opportunity for health risk reduction for people served by public water systems. EPA included PFOA and PFOS among the contaminants for which, water systems are required to monitor under the third Unregulated Contaminant Monitoring Rule (UCMR 3) in 2012.

Q:   How are PFOA and PFOS removed from source waters?
A:  PFOA and PFOS can be removed using a number of advanced drinking water treatment technologies, including Granular Activated Carbon (GAC), ion exchange, and blending treatment processes. To the extent possible, Golden State Water has removed water sources with PFOA and/or PFOS detections above notification level out of service and plans to install treatment for sources above the response level.

Resources for Additional Information

State Water Resources Control Board
U.S. Environmental Protection Agency
U.S. Environmental Protection Agency (PFOA/PFOS Fact Sheet)
GSWC PFAS Fact Sheet