Lead in Drinking Water

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DSRSD Potable Water Service Line Inventory

To ensure that public water systems are reducing lead exposure in our country’s drinking water systems, the U.S. Environmental Protection Agency requires all large public water systems to create an inventory of potable (drinking) water service line materials and post this information on their websites by October 16, 2024. View the DSRSD Potable Water Service Line Inventory here.

Flint, Michigan Drinking Water

Events in Flint, Michigan, had people across the country asking questions about lead in drinking water. Could it happen here? It is very unlikely, for several reasons:


	Laboratory Supervisor Connie Sanchez tests water samples on an instrument that can detect contaminants to the level of a few parts per trillion. DSRSD's lab uses this instrument to test tap water samples for lead and copper.

Flint has thousands of lead water pipes and old plumbing fixtures. DSRSD has never used lead pipes in its distribution system.
Flint changed its water source, which altered the water’s pH balance. As a result, their water became extremely corrosive and the city did not implement a corrosion-control program. Here, Zone 7 Water Agency adjusts the pH of our water to make it as non-corrosive as possible. Approved by the state’s Division of Drinking Water, Zone 7‘s corrosion-control program has been working effectively for decades, and there has been no significant change in our water supply since corrosion control began.
DSRSD and Zone 7 regularly test the water in accordance with all state and federal requirements to ensure it is safe to drink.

Frequently Asked Questions

Expand/Contract Questions and Answers

Why is lead harmful?
If present, elevated levels of lead can cause serious health problems. Pregnant women, infants and young children are typically more vulnerable to lead in drinking water than the general population. You cannot smell or taste lead in water, and it is not visible to the naked eye.
How does lead get into tap water?

Plumbing and faucets in homes built before 1986 are most likely to contain lead.

Lead leaches into drinking water from the corrosion of plumbing or fixtures that contains lead. Even though California now requires new household plumbing, fixtures, and solder to be lead-free, lead is still present in some older pipes and faucets, and in the older solder that was used with copper pipes. These problems are most likely to occur in houses built before 1986.

The chemistry of water either increases or decreases its ability to dissolve the metals in plumbing. Water that is acidic (pH below 7.0) tends to be corrosive, or “aggressive.” Water that is alkaline (pH above 7.0) is not corrosive or “aggressive.” Zone 7 Water Agency maintains a slightly alkaline pH in our water supply to help prevent any lead that might be present from leaching into your tap water.
How is our water tested for lead?
Both Zone 7 and DSRSD test water samples for lead. Zone 7 does monthly tests to measure the amount of lead in the public water supply. These tests routinely show less than one part per billion of lead in the water. That’s far below the level where any corrective action is required (15 parts per billion). In addition, Zone 7 monitors the pH of the water 24 hours a day at its treatment plants to ensure it stays non-corrosive to plumbing.

Every three years, DSRSD is required to test the indoor tap water from a sample of homes built before 1986, when plumbing fixtures like faucets and pipe solder were allowed to contain lead. We last performed these tests in 2016. The EPA requires that 90 percent of the samples be below the regulatory action level. The District’s results were much better than this standard. Of the 30 homes tested, 28 (93 percent) were below the action level. While we were not required to take any action with the two homeowners whose results were at or above the action level, our staff advised them of the advantages of replacing old plumbing and fixtures with new lead-free materials. We published a summary of test results in our Annual Water Quality Report.
Should I have my water tested for lead?
If you are concerned about lead in your drinking water, you may want to have it tested. The EPA recommends using a laboratory accredited by the state Environmental Laboratory Accreditation Program (ELAP). Three accredited labs that do drinking water testing for consumers are listed below. The EPA website has more helpful information about testing your water for lead, or you can call the EPA Safe Drinking Water Hotline if you have questions: (800) 426-4791.

Alpha Analytical Laboratories
925-828-6226
Livermore, CA

CalTest Analytical Laboratory
707-258-4000
Napa, CA

Torrent Laboratory
408-740-3624
Milpitas, CA
Will DSRSD test my home's water for lead?
No, DSRSD's laboratory does not offer a commercial testing service. We select participants for our mandatory triennial tests based on specific parameters set by state and federal regulations so we cannot accept volunteers.
How can I reduce my exposure to lead in drinking water?
If you are concerned there may be lead in your home's plumbing, you can reduce potential lead exposure by flushing out water that has been sitting in the pipes for six hours or more. Run the faucet for 30 seconds to 2 minutes before using the water for drinking or cooking. (Please capture and reuse this water for other purposes such as watering ornamental plants.) Also, use water from the cold-water tap for drinking, cooking, and especially for making baby formula. Lead leaches more easily into hot water than cold water.
Will a water filter protect my family from lead exposure?
The EPA says there are home water filters certified for effective lead reduction, but devices that are not designed to remove lead will not work. If you ever discover that you have high levels of lead in your tap water, you should consider using bottled water or an appropriate water filter until you replace old plumbing and fixtures. For more information, visit the EPA website or call the EPA Safe Drinking Water Hotline: (800) 426-4791.