IRWD’s Drinking Water is Safe


IRWD drinking water does not contain PFAS (PFOS/PFOA)

The drinking water we provide to homes, businesses and schools is safe and meets all quality standards set by both the state and federal government. IRWD water quality experts continuously monitor the water supply and conduct hundreds of laboratory tests each year from water taken from sample points throughout the IRWD service areas. The test results are published by IRWD in the annual Water Quality Report.


What are PFOS and PFOA?

Perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) are fluorinated organic chemicals that are part of a larger group of man-made chemicals referred to as per-and polyfluoroalkyl substances (PFAS), which are generally resistant to heat, water, and oil. 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 water proof, stain-resistant or non-stick.


How does PFAS get into the drinking water?

PFAS can get into drinking water when products containing them are used or spilled onto the ground or into lakes and rivers. PFAS move easily through the ground, getting into ground water that may be used for water supplies or for private drinking water wells. Such contamination is typically localized and associated with a specific facility, such as an industrial facility where these chemicals were manufactured or used in other products, or an air field which used the chemicals for firefighting. People can also be exposed to PFAS through food, food packaging, consumer products, and house dust.


What has been done to regulate PFOS/PFOA?

Between 2000 and 2002, PFOS was voluntarily phased out of production in the United States by its primary manufacturer. Beginning in 2006 other manufacturers began to voluntarily limit the number of on-going uses. Although most of the PFAS chemicals are no longer manufactured in the United States, other countries still produce PFOA and PFOS and products that contain them may be imported, such as carpets, leather and apparel, textiles, paper and packaging, coatings, rubber, and plastics.


What are the State and Federal regulations governing PFOS/PFOA?

In May 2016, the United States Environmental Protection Agency (EPA) issued a lifetime health advisory for PFOS and PFOA for drinking water, advising municipalities that they should notify their customers of the presence of levels over 70 parts per trillion in community water supplies. EPA recommended that customer notifications include information on the increased risk to health, especially for susceptible populations.

Originally adopted in June 2018 and lowered in August 2019, California’s Office of Environmental Health Hazard Assessment (OEHHA) recommended interim notification levels for PFOA (based on liver toxicity, as well as cancer risks), and for PFOS (based on immunotoxicity). After independent review of the available information on the risks, the California Water Board Division of Drinking Water (DDW) established notification levels for PFOS and PFOA (6.5 parts per trillion for PFOS and 5.1 parts per trillion for PFOA), as well as a single health advisory response level (of 70 parts per trillion) which offers a margin of protection for all persons throughout their life from adverse health effects resulting from exposure to PFOA and PFOS in drinking water. A nanogram is also known as a “part-per-trillion,” and one nanogram per liter is the equivalent of four grains of sugar dissolved in an Olympic-sized swimming pool.


What are Notification Levels?

Notification Levels are precautionary health-based advisory levels established by the California DDW while further research and analysis are conducted by the state to determine the necessity of setting an enforceable drinking water maximum contaminant level (MCL). Notification Levels are based on the most sensitive known health endpoints for these compounds: lifetime cancer risk, liver toxicity, and immunotoxicity. Both the California DDW and the federal EPA have indicated their intent to publish an enforceable drinking water MCL; however, this process will require a minimum of three to four years.


IRWD and DDW Statewide PFAS Testing

In June 2018, the State Water Resources Control Board Division of Drinking Water adopted Notification and Response Levels for PFOA and PFOS. These are health-based non-regulatory thresholds. IRWD proactively tested for the presence of PFOA and PFOS in August 2018. IRWD’s Well OPA-1, located near the Santiago Creek Recharge Basin, had detectable results above the Notification Levels but below the Response Level for PFOA and PFOS. IRWD voluntarily stopped serving the water from OPA-1 in September 2018 and this well has remained out of service since then.

In response to a statewide investigation of PFOA and PFOS by the Division of Drinking Water initiated in March 2019, IRWD retested its OPA-1 well twice. The monitoring results confirmed that OPA-1 remains over the Notification Levels for PFOA (15.4 and 16.3 ppt) and PFOS (23.8 and 26.2 ppt). IRWD, in collaboration with Orange County Water District, has initiated a study of potential groundwater treatment options.

The State’s Division of Drinking Water has also requested that drinking water wells within two miles of airports be tested for PFOA and PFAS. IRWD has a well, Dyer Road Well Field Well 02, that is within two miles of John Wayne Airport. This well has been out of service since the spring of 2018 for rehabilitation and has not yet been tested. Once the rehabilitation of Well 02 is complete, the groundwater from this well will be tested. Well 02 will remain out of service until testing is completed and analyzed.


What is IRWD doing to protect our drinking water from PFOS and PFOA?

We are working with other water utilities and the Orange County Water District to better understand impacts in the groundwater basin and treatment technologies. We will stay abreast of regulatory developments to ensure ongoing compliance with all drinking water standards and requirements, and most importantly IRWD will continue to monitor water quality to assure that our drinking water remains safe. PFOS and PFOA have been detected in water throughout the United States. To learn more about PFOS and PFOA please see this fact sheet.


updated: 8/26/2019

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