Regulatory Compliance

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 2024, we tested for 240 constituents in the water and performed more than 102,500 tests on samples taken throughout our water system. LADWP complied with all the primary drinking water standards in 2024.

Chlorate

In June 2024, LADWP detected chlorate above the CA notification level of 800 parts per billion (ppb) in the Griffith Park area of the water distribution system. Chlorate was detected above the notification level at the Griffith Park Crystal Springs Pump Station. The highest value found was 820 ppb. A notification level is a health-based advisory level, but not an enforceable standard.

Griffith Park is a small, isolated section of the overall water distribution system that serves transient visitors and workers in Griffith Park but does not serve residences. It is the only portion of the LADWP distribution system that uses chlorine disinfection. The chlorate forms due to a combination of age and temperature of the sodium hypochlorite solution used in the chlorine disinfection process. LADWP has made improvements to procedures for sodium hypochlorite storage and chemical change-outs, which has led to better control of chlorate at Griffith Park.

Poly- and Perfluoroalkyl Substances and Drinking Water in California

Poly- and Perfluoroalkyl Substances (PFAS) are a group of synthetic (man-made) chemicals which include Perfluorooctanoic acid (PFOA) and Perfluorooctanoic sulfonic acid (PFOS). This category of manufactured chemicals that have been used in industry and consumer products since the 1940s have characteristics that make them useful in a variety of products, including nonstick cookware, waterproof clothing, and firefighting foam, as well as in certain manufacturing processes. PFAS tends to break down very slowly in the environment, and 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 the U.S. EPA’s website on PFOA and PFOS health advisories.

On April 10, 2024, the U.S. EPA announced the final National Primary Drinking Water Regulation (NPDWR) for six PFAS compounds. In this regulation, U.S. EPA established regulatory standards with Maximum Contamination Levels (MCL) for five individual PFAS in drinking water, PFOA (4 parts per trillion or ppt), PFOS (4 ppt), Perfluorohexanesulfonic acid (PFHxS) (10 ppt), Perfluorononanoic acid (PFNA) (10 ppt), and Hexafluoropropylenedimer acid (HFPO-DA) (10 ppt), along with a hazard index level MCL for PFAS contamination mixtures, which also includes Perfluorobutanesulfonic acid (PFBS). EPA also finalized health-based, Maximum Contamination Level Goals for these PFAS.

The U.S. EPA also issued the fifth Unregulated Contaminant Monitoring Rule (UCMR5) to improve U.S. EPA’s understanding of the frequency that 29 PFAS are found in the nation’s drinking water systems. LADWP collected samples for UCMR5 from 2023-2024.

LADWP continues to monitor its groundwater sources for PFAS since it began testing in 2013 and has analyzed hundreds of samples utilizing EPA approved testing methods. Although PFAS have been detected in some individual wells; that well water is blended and diluted with large volumes of surface water before it is served to customers. LADWP has not detected any PFAS compounds regulated by the State of California, or the U.S. EPA, in samples taken at entry points to the distribution system. LADWP’s ongoing monitoring program and commitment to water quality and safety ensure that our water meets or exceeds all regulatory standards.

If you have questions, please contact our Water Quality Hotline at (213) 367-3182 or email us at waterqualityoffice@ladwp.com.

Lead and Copper Regulations in Los Angeles

LADWP has a long and successful history safeguarding our customers from lead exposure in several ways. LADWP utilizes infrastructure pipes, meters, and materials that do not contain lead. Between 1978 and 2006, LADWP cleaned and cement-lined approximately 2,600 miles of unlined iron pipes (greater than four inches in diameter). In another proactive effort, LADWP’s staff had located and removed approximately 12,000 known lead goosenecks from its water distribution system by 2005. LADWP was also one of the first utilities to incorporate the lead-free standard by initiating a program in 1998 to replace low-lead (8 percent lead) water meters with lead-free (0.25 percent lead) water meters. As of December 2024, more than 580,000 of the roughly 700,000 active water meters in LADWP’s water distribution system have been replaced.

LADWP also ensures that the water served to our customers is non-corrosive. Corrosion is a natural process that occurs when materials undergo chemical reactions that result in their deterioration. The SWRCB evaluated LADWP’s corrosion control program and has deemed our system to be optimized for controlling corrosion.

Under the Lead and Copper Rule Revisions, LADWP also completed an inventory of the service line materials and service connectors in the distribution system. In 2021, LADWP completed the utility-side inventory, and no lead service lines were found. In 2022, LADWP began assessing the customer-owned service lines for the presence of lead, and if detected, the lines would be replaced. The assessment was completed in October 2024 with the conclusion that no lead service lines are present in LADWP’s distribution system. LADWP achieved a non-lead designation from the SWRCB. For more information on this, please visit LADWP’s water quality website. LADWP will continue to protect the public from exposure to lead by implementing the Lead and Copper Rule Improvements regulation that was finalized by the U.S. EPA on October 8, 2024.

LADWP regularly tests for lead and copper in our distribution system and in customer homes that have been identified as ideal for our residential testing efforts. As part of this continuing effort, LADWP conducted residential sampling for lead and copper in 2023 as part of the Lead and Copper Rule (LCR) tap water sampling program. This program focuses on single family residences built between 1982 to 1987, which are expected to have copper pipes plumbed with lead solder. Customers with qualifying homes that participated in the sampling program had their tap water tested for lead and copper at no cost. During the 2023 sampling program, 105 first draw samples were obtained from customers’ homes and analyzed at LADWP’s Water Quality Laboratory. The results showed a 90th percentile of 3.9 ppb for lead and 529 ppb for copper. Both values were well below the respective Action Levels of 15 ppb for lead and 1,300 ppb for copper. The next LCR sampling round will be conducted in 2026.