Lead Testing

The delivery of safe water to the San Diego County Water Authority’s 24 retail member agencies and their customers is a top priority for the Water Authority.

The Water Authority regularly tests for the presence of lead and other potential contaminants in its supply sources and in the water it delivers to member agencies as part of its overall water quality monitoring program, using a range of techniques from real-time monitoring to laboratory testing. Tests show no detectable levels of lead in any potable water from any treatment plant for the Water Authority’s supplies. Regular water quality monitoring and the use of online monitoring equipment ensure that the Water Authority is delivering the high quality and safe water to its member agencies 24 hours a day, seven days a week. 

Water Authority’s Protocols for Testing for Lead in its Supplies


Potable water supplied by the Water Authority to its member agencies comes from three primary sources: the Claude “Bud” Lewis Carlsbad Desalination Plant, the Robert A. Skinner Water Treatment Plant in Riverside County – owned and operated by the Metropolitan Water District of Southern California – and the Twin Oaks Valley Water Treatment Plant in San Marcos.

The source water for the Carlsbad desalination plant is seawater from the Agua Hedionda Lagoon, while the source water for the Skinner and Twin Oaks Valley treatment plants are from the State Water Project in Northern California and the Colorado River.

Each of these source waters is tested for lead at least annually in accordance with regulations from the U. S. Environmental Protection Agency and the State Water Resources Control Board - Division of Drinking Water. These agencies generally require that water agencies in California sample and test their source waters annually, and conduct additional samples at multiple established locations in their distribution system every three years. Local reservoirs are tested at least annually in accordance with state and federal water quality rules.

Special lead sampling was required when desalinated seawater from the Claude “Bud” Lewis Carlsbad Desalination Plant was added to the Water Authority’s supplies. Results from this sampling showed that all systems receiving the desalinated water were in compliance with state and federal regulations. 

Data compiled January through December 2016 from the testing of water output by the three facilities treating Water Authority source water show no detectable levels of lead in any potable water from any treatment plant for the agency’s supplies.

Here are 2016 test results for the following facilities:

• Claude “Bud” Lewis Carlsbad Desalination Plant

• Robert A. Skinner Treatment Plant in Riverside County

• Twin Oaks Valley Water Treatment Plant

Water Authority member agencies are required to perform lead testing for their own systems in accordance with federal and state regulations. For consumer confidence reports specific to each member agency, go to www.sdcwa.org/water-quality-reports.

New Rule for Lead Testing at California’s K-12 Schools


Public concern over lead issues in other states’ drinking water supplies prompted the state Division of Drinking Water to enact a new requirement for the testing of water for lead in schools.

Under the new requirement, testing is voluntary for schools, but if the schools make a written request, the local retail water agency (such as any of the Water Authority’s 24 member agencies) must collect the samples and report the results back to the school within prescribed time limits. This rule went into effect in January 2017.

The requirements of California’s rule include:

• The community water systems (local retail agencies) are responsible for the costs associated with collecting drinking water samples, analyzing them and reporting results.

• Sampling locations can include drinking fountains, cafeteria and food preparation areas, and reusable water bottle filling stations.

• Schools can request a sampling under the program any time prior to November 1, 2019.

Additional Information

When lead is detected at the customer level, the most common cause is internal corrosion of plumbing systems and service lines that are owned by the property owner.

Consumers who are concerned about lead in drinking water can learn more by visiting the EPA’s website or by calling the Safe Drinking Water Hotline toll free at 1-800-426-4791 to speak with an Information Specialist during hours of operation. Bilingual service, including recorded messages, is available 24 hours per day, seven days per week through the hotline.