In August 2019, the Division of Drinking Water (DDW) set the customer Notification Level of 5.1 parts per trillion (ppt) for PFOA and 6.5 ppt for PFOS and in February 2020, set new a Response Level of 10 ppt for PFOA and 40 ppt for PFOS. In March 2021, DDW issued the notification level and response level for PFBS of 500 ppt and 5000 ppt, respectively. In October 2022, DDW issued the notification level and response level for PFHxS at 3 ppt and 20 ppt, respectively.
A notification level is a nonregulatory, precautionary health-based measure for concentrations of chemicals in drinking water that warrant notification and further monitoring and assessment.
A response level is a nonregulatory, precautionary health-based measure that is set higher than a notification level and represents a recommended level that water systems consider taking a water source out of service or provide treatment if available to them.
In March 2019, the California State Water Resources Control Board (State Board) began a state-wide PFAS investigation and issued orders to approximately 200 water utilities throughout California to test groundwater wells that are in close proximity to fire training/fire response sites (e.g., airfields), industrial sites, landfills, and/or wastewater treatment plants for PFAS. Since ACWD groundwater sources are not located in close proximity to potential sources of contamination, ACWD was not issued orders to monitor for PFOA, PFOS, or PFBS by DDW.
Assembly Bill 756 that took effect on January 1, 2020, authorized the State Board to more broadly order water systems to monitor for PFAS and report their detections. ACWD was not issued an order under the Assembly Bill.
In October 2022, DDW issued monitoring orders to numerous water agencies, including ACWD, to monitor all groundwater sources effective January 1, 2023. The provisions of the Order are similar to the voluntary monitoring program that ACWD began in June 2020. ACWD will continue to monitor sources on a quarterly basis.
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PFAS are manmade compounds that have been used to make carpets, clothing, fabrics for furniture, paper packaging for food, electronics, personal hygiene products, and other materials (e.g., cookware) designed to be waterproof, stain-resistant, or non-stick. Of particular interest are four compounds that have notification levels. Perfluorooctanoic Acid, more commonly referred to as PFOA, Perfluorooctane Sulfonic Acid, or PFOS, Perfluorobutane Sulfonic Acid or PFBS, and Perfluorohexanesulfonic Acid or PFHxS.
In recent years people have become more familiar with the term PFAS. Although awareness of these manmade chemical compounds is recent, PFAS have been in wide use since the 1940s.
Used in many consumer and industrial products for their ability to repel stains, water, and oil, PFAS are persistent in the environment and do not readily degrade. They also are prevalent in many items we encounter daily – inside and outside the home. While items imported from outside the United States may contain PFAS, its use is being phased out in the US.
According to the US EPA, there is evidence that exposure to PFAS can lead to adverse health outcomes in humans. If humans, or animals, ingest PFAS (by eating or drinking food or water than contain PFAS), the PFAS are absorbed, and can accumulate in the body. PFAS stay in the human body for long periods of time. As a result, as people get exposed to PFAS from different sources over time, the level of PFAS in their bodies may increase to the point where they suffer from adverse health effects.
Studies indicate that PFOA, PFOS, PFBS, and PFHxS can cause reproductive and developmental, liver and kidney, and immunological effects, and decreased thyroid hormone levels in laboratory animals. The most consistent findings from human epidemiology studies are increased cholesterol levels among exposed populations, with more limited findings related to:
ACWD tested drinking water supplies for PFOA and PFOS compounds in 2014, as required by the United States Environmental Protection Agency under the third Unregulated Contaminant Monitoring Rule. ACWD did not detect PFOA or PFOS in the drinking water in 2014.
Since 2014, advances in testing technologies since 2014 have allowed us to detect substances at increasingly low levels. Therefore, ACWD, once again, in June 2020, voluntarily sampled several water supply sources ahead of any regulatory requirement. This proactive monitoring allows ACWD to ensure the best water quality is available to our customers and take measures to treat our source supplies.
Our voluntary testing identified low levels of PFOA in our groundwater sources between non-detect and 6.4 ppt, with some sources above the customer notification level of 5.1 ppt. However, all treated water delivered to customers had no detections of PFOA.
PFOS was detected in most groundwater sources at low levels, between non-detect and 15 ppt, with some sources above the customer notification level of 6.5 ppt set by the State Board. However, all treated water delivered to customers was below the notification level or non-detectable.
PFBS was detected in some groundwater sources at low levels, between non-detect and 7.4 ppt, with all sources below the customer notification level of 500 ppt. All treated water delivered to customers had no detections of PFBS.
PFHxS was detected in most groundwater sources, between non-detect and 14 ppt, with most of the sources above the customer notification level of 3 ppt. Since the establishment of the notification level, ACWD has optimized operations to ensure all treated water delivered to customers remain below notification levels.
Results from this same monitoring program did not detect PFOA, PFOS, or PFBS in surface water supplies which account for almost two-thirds of ACWD’s total water delivered to our customers.
Samples were collected by trained sampling staff from locations where other regulatory water quality samples are collected and analyzed by a State Certified Laboratory.
As per the State Board Monitoring Order that was issued in October 2022 and is effective January 1, 2023, ACWD will continue the quarterly groundwater monitoring as it has been doing voluntarily since June 2020.
ACWD has existing water treatment facilities in place to effectively safeguard your water supply with the use of reverse osmosis technology at our Newark Desalination Facility and the blending of groundwater and surface water at our Blending Facility. Both these methods are already implemented at our treatment facilities and have managed to keep the detections below the notification levels, thereby ensuring the treated water supplied to our customers meets all health-based standards.
Federal and State MCLs are expected for select PFAS compounds in 2023 and 2025, respectively. In anticipation of MCL establishments, ACWD is designing and building a treatment facility to address PFAS in groundwater at our Blending Facility. Currently in design, the facility will treat up to 6 million gallons per day (MGD) of PFAS-impacted groundwater and may be potentially expanded to treat up to 15 MGD in the future, if needed. In addition, the facility will restore reduced capacity that resulted from operational changes needed to minimize PFAS levels in the treated water delivered to customers.
ACWD will post PFAS sampling results on its website and additionally provide the sample results to the State Water Resources Control Board Division of Drinking Water who will also post it on their website.
The latest data is available at acwd.org/PFAS
More information on PFOA, PFOS, and PFBS is available at https://www.epa.gov/pfas or the California Water Board Frequently Asked Questions https://www.waterboards.ca.gov/pfas/docs/pfas_general_faq.pdf