PFOA / PFOS / PFAS in Drinking Water

PFOA / PFOS / PFAS Chemicals

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are fluorinated organic chemicals that are part of a larger group of man-made chemicals referred to as per-and poly-fluoroalkyl substances (PFAS). 

PFAS are synthetic compounds. They have been used extensively in consumer products such as carpets, clothing, fabrics for furniture, paper packaging for food, fire-fighting foams, and other materials (e.g. cookware) designed to be waterproof, stain-resistant, or non-stick. Two of the most well-known chemicals, PFOS and PFOA, have been phased out in the United States, but they do not break down easily and can linger in the environment. In fact, most people in the U.S. have PFAS in their blood. People are typically exposed through ingestion by eating foods from packaging containing PFOS/PFAS, inhaling certain fabric sprays, or breathing air with dust from contaminated soil, carpets, and clothing.

The presence of PFOS/PFAS in source water and drinking water is complex and concerning to water professionals due to their widespread use and environmental persistence. Continued exposure to high levels of specific PFOS/PFAS can lead to adverse health effects. Rancho Water takes any risks to water quality seriously. The District will continue to closely monitor the quality of the community's drinking water supplies and track the latest information on PFAS.

Frequently Asked Questions

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What are PFAS?

Per-and-poly-fluoroalkyl substances, commonly referred to as PFAS, are a family of over 12,000 man-made chemicals that are sometimes referred to as “forever chemicals”. PFAS are resistant to fire, water, and oil. Because of these qualities, they have historically been used in a vast array of products including non-stick cookware, food packaging, household cleaning products, makeup/cosmetics, clothing, and firefighting foam. PFAS have been used in manufacturing worldwide since the 1940s, however, many PFAS chemicals have been phased out from their use in commercial products and several laws have been passed in California to ban these chemicals entirely from most products including cleaning products, firefighting foam, textiles, and make-up.

How Can I Be Exposed to PFAS?

People can be exposed to PFAS through:

  • • Eating foods containing PFAS
  • • Drinking water containing PFAS
  • • Breathing PFAS through the air
  • • Using products made with or packaged in materials containing PFAS
  • • Working in occupations such as firefighting or chemical manufacturing
Items with PFAS

How Does PFAS get into Water & Wastewater Supplies?

According to the California State Water Resources Control Board, the four largest sources of PFAS contamination are fire training/firefighting response, industrial sites, landfills, and wastewater treatment plants that may serve as passive receivers of PFAS. Areas with high amounts of industrial activity are more susceptible to PFAS contamination in their water supplies.

Pools PFAS

At What Level is PFAS Considered Unsafe?

On March 14, 2023, the U.S. Environmental Protection Agency (EPA) announced a proposed rule for regulating PFAS in drinking water of 4 parts per trillion (4 ppt), and they anticipate finalizing regulations by the end of 2023. Over the next year, the proposed rule will be vetted through a public review process. For context, 4 ppt is equivalent to 4 grains of sand in 20 Olympic-sized swimming pools. Prior to this proposed rulemaking, the United States Environmental Protection Agency required water agencies to notify their customers if PFAS was detected at levels over 70 parts per trillion. Research is still ongoing to better understand the potential health effects of PFAS exposure over long periods of time.

What is Rancho Water Doing to Address PFAS?

Rancho Water maintains a strict testing regime for our water and our primary purpose is to provide a reliable water supply while protecting public health and safety. In line with our commitment to public health, we test our water over 2,000 times per year to ensure that the District meets or surpasses all state and federal drinking water standards. This year, three out of our forty-three groundwater wells tested positive for low concentrations of PFAS. Out of an abundance of caution, Rancho Water promptly took these wells out of service and we are preparing to install state-of-the-art filtration technology in order to remove PFAS from the three wells, ensuring that our water is always up to our highest standard.

Additional Information

To learn more about Rancho Water's drinking water quality, customers can view the District's annual Water Quality Reports (PDF). Customers who want a hard copy of the report may email the Public Information Department or call 951-296-6933. 

(Note: PFOS/PFAS sampling is not included in Rancho Water's 2022 water quality report, as the District was not required to report on chemicals that were not detected at the time of sampling.)