How did we measure up?

LADWP works around the clock to ensure that the drinking water we deliver to our customers is of the highest quality and meets all safety requirements. Highly trained, certified treatment operators monitor our water treatment operations continuously, thereby helping meet federal and state standards for drinking water. In 2022, we tested for more than 200 constituents in the water and performed more than 107,000 tests on samples taken throughout our water system. LADWP complied with all the primary drinking water standards in 2022.

    PFAS and Drinking Water in California

    Poly- and Perfluoroalkyl Substances (PFAS) are a group of synthetic (man-made) chemicals, which include Perfluorooctanoic acid (PFOA) and Perfluorooctane sulfonic acid (PFOS). They have been used for decades in manufacturing. They are also suspected carcinogens and don’t breakdown. Most U.S. manufacturers voluntarily phased out production of PFOS between 2000 and 2002, and PFOA in 2006.

    Studies indicate potential health consequences from exposure to significant levels of PFAS. Health effects may include high cholesterol, liver and thyroid cancer risks, immunotoxicity, pregnancy-induced hypertension, low birth weights, and decreased fertility. More information is available on U.S. EPA’s webpage on Drinking Water Healthy Advisories for PFOA and PFOS.

    The California State Water Resources Control Board (State Board) has been actively investigating and sampling for PFAS since 2019. Updated drinking water response levels remained 10 parts per trillion for PFOA and 40 parts per trillion for PFOS during the course of the year. Additionally, two other PFAS constituents in the PFAS family have recently been assigned response levels by the Division of Drinking Water. Those chemicals are Perfluorobutane sulfonic acid (PFBS) and Perfluorohexane sulfonic acid (PFHxS). In 2022, the State Board issued a new PFAS Monitoring Order with compliance to begin in the first quarter of 2023 to monitor for these 4 PFAS chemicals as well as 21 others.

    At the Federal level, the U.S. EPA released a proposal to designate two of the most widely used per- and polyfluoroalkyl substances PFAS as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), also known as “Superfund.” This rulemaking would increase transparency around releases of these harmful chemicals and help to hold polluters accountable for cleaning up their contamination. The proposal applies to PFOA and PFOS.

    They also issued the fifth Unregulated Contaminant Monitoring Rule to improve U.S. EPA’s understanding of the frequency and levels that 29 PFAS are found in the nation’s drinking water systems. The U.S. EPA is preparing to propose a PFAS National Drinking Water Regulation by the end of 2023.

    LADWP has continued to monitor its groundwater sources for PFAS since it began testing in 2013. After analyzing hundreds of samples utilizing the approved test methods, LADWP has not found contamination issues in its water supplies. Although PFAS were detected in a few samples from individual wells, the extracted water is blended with water from other wells and is further diluted with superior volumes of surface water before entering the distribution system. Customers can be confident that LADWP is providing high quality drinking water. If you have questions, please contact our Water Quality Hotline at (213) 367-3182 or email us at [email protected].

    Revised Lead and Copper Rule

    LADWP has started implementing an action plan to comply with the Lead and Copper Rule Revisions (LCRR), which went into effect in 2021 and have requirements starting in 2024.

    1. Customer side plumbing inventory was started in May 2022.
    2. A vendor has been selected to develop a predictive modeling tool that can determine the composition of customer-owned service lines in the city.
    3. Additional resources and supplies continue to be secured.

      Safeguarding Our Surface Water

      Source water protection is an important component in delivering safe drinking water. Source water assessment updates are required by the SWRCB-DDW and must be included in the annual drinking water quality report. LADWP completed an initial source water assessment in 2002 and is required to provide an updated assessment every five years through a watershed sanitary survey. Watershed sanitary surveys examine possible contamination to sources of drinking water and recommend actions to better protect these water sources.

      The following is an update of LADWP’s source water assessment:

      Surface Supply:

      In 2020, LADWP completed an assessment of the Owens Valley and Mono Basin watersheds that supply the Los Angeles Aqueduct. These sources are most vulnerable to geothermal activities that release naturally occurring arsenic into creeks which feed the Owens River. Assessments were also completed for the Lower Stone Canyon Reservoir Watershed in 2019 and Encino Reservoir Watershed in 2020. Activities that impact water quality in these watersheds are livestock grazing, wildlife, and unauthorized public use of storage reservoirs. The impact to water quality from these activities is deemed to be minimal.

      LADWP regularly monitors for Cryptosporidium and Giardia. Results indicate that their presence is infrequent and remain at very low levels in these watersheds.

      Groundwater Supply:

      Assessment of groundwater sources in the San Fernando Basin was updated in 2018. Assessment of groundwater sources in the Central and Sylmar Basins was completed in 2019. Located in highly urbanized areas, the wells within these aquifers are most vulnerable to the following activities: dry cleaning, manufacturing, metal finishing, septic systems, chemical processing, and storage of fertilizer, pesticides, and chemicals. These local water supplies are treated and blended with water from other sources to ensure compliance with drinking water standards.

      Purchased Imported Supplies from MWD:

      The most recent surveys for Metropolitan Water District’s (MWD) source waters are the Colorado River Watershed Sanitary Survey – 2020 Update, and the State Water Project Watershed Sanitary Survey – 2021 Update. Each source water used by MWD, the Colorado River and State Water Project, has different water quality challenges. Both are exposed to stormwater runoff, recreational activities, wastewater discharges, wildlife, fires and other watershed-related factors that could affect water quality. Treatment to remove specific contaminants can be more expensive than measures to protect water at the source. This is why MWD and other water agencies invest resources to support improved watershed protection programs.

      Three of the five MWD treatment plants: F.E. Weymouth, Robert B. Diemer, and Joseph Jensen, supply water to the Los Angeles area. MWD tests its water for nearly 400 constituents and performs about 250,000 water quality tests per year on samples gathered from its vast distribution system. Analysis of these samples is undertaken at Metropolitan’s water quality laboratory. Results from MWD are provided to LADWP and are included in the report on Tables I, II and III.

      Safeguarding our Surface Water

      Administered by the SWRCB-DDW, the Surface Water Treatment Rule (SWTR) is a set of drinking water regulations that establish specific treatment requirements for surface water to reduce the risk of waterborne diseases.

      The last update to the SWTR is the Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR). This rule protects treated water reservoirs from microbiological contamination by requiring one of three actions: 1) covering, 2) removing from service, or 3) providing additional treatment. LT2ESWTR applied to the six remaining uncovered reservoirs at the time: Los Angeles, Upper Stone Canyon, Santa Ynez, Ivanhoe, Silver Lake, and Elysian.

      LADWP has implemented several projects over the past 25 years at a cost of over $1.5 billion to comply with LT2ESWTR. Several uncovered finished storage facilities and open reservoirs were either covered, removed from service, or provided with additional treatment. The Los Angeles Reservoir was brought into compliance through a combination of shade balls deployed in 2015 and the completion of the Los Angeles Reservoir Ultraviolet Disinfection Plant (LARUVDP) in January 2022. The LARVUDP was the final step in meeting all the conditions set forth by the 2009 compliance agreement with DDW and ensures that water provided by LADWP complies with all primary state and federal requirements.

      Visit LADWP’s Water Quality webpage to learn more about water quality projects and issues. For more information on the latest watershed sanitary surveys contact (213) 367-3182.

        Compliance with the Lead and Copper Rule (LCR) in Los Angeles

        LADWP has a long and successful history of controlling corrosion and minimizing lead exposure to customers. Between 1978 and 2006, LADWP cleaned and cement-lined approximately 2,600 miles of unlined iron pipes four inches in diameter and greater. LADWP initiated another program in 1998 to replace low-lead (8% lead) water meters with lead-free (0.25% lead) water meters. There are currently over 700,000 active water meters in LADWP’s water distribution system. The goal is to replace approximately 31,500 meters annually, and 32,825 meters were replaced in 2022. In another proactive effort, LADWP’s staff located and removed approximately 12,000 known lead goosenecks from its water distribution system by the year 2005. In 2018, LADWP completed an inventory of its remaining unknown utility-owned services lines—none consisted of lead material.

        LADWP most recently conducted the LCR residential sampling in 2020. During the sampling program, 100 first draw samples were obtained from customers’ homes and analyzed at LADWP’s water quality laboratory. The results showed a 90th percentile of 5.0 ppb (parts per billion) for lead and 394 ppb for copper. Both values were well below the respective Action Levels of 15 ppb for lead and 1300 ppb for copper. Since 90th percentile results are below the Action Limits, the SWRCB-DDW approved reducing LCR sampling to once every three years. The next sampling will be in 2023.

        LCR Program Requirements

        The LCR sampling program focuses on single family residences built between 1982 to 1987, and those that have copper pipes plumbed with lead solder. Customers with qualifying homes that participate in the sampling program will get their tap water tested for lead and copper at no cost.

        Customers who think their home may qualify can participate in LADWP’s next round of LCR sampling between June and September, 2023. Contact the Water Quality Hotline.

        Information on lead in drinking water, testing methods, and steps you can take to minimize exposure is also available from the U.S. EPA Safe Drinking Water Hotline.