Problems We Found In San Francisco, California Drinking Water


Analies Dyjak, M.A.  |  Hydroviv Research Analyst
**Updated May 3, 2021 to include current data

Our Water Nerds have updated our water quality assessment for San Francisco drinking water. We used the most recent 2020 test data from San Francisco Water, Power & Sewer, the city’s water provider and the U.S. Environmental Protection Agency (EPA), as well as from samples that we collect and analyze. We cross reference these data with toxicity studies in the scientific and medical literature, and delve into upcoming regulatory changes. The custom water filters that we offer at Hydroviv are optimized with San Francisco's water quality in mind.

Source Of San Francisco Drinking Water

San Francisco source water originates from the Tuolmne River, and is stored in the Hetch Hecthy Reservoir. Water from the Hetch Hetchy is supplemented with water from local watersheds such as the Alameda, Peninsula, San Andreas, and Pilarcitos reservoirs. Emergency supplies include Lake Eleanor, Lake Cherry and tributaries of the Lower Cherry Aqueduct, Early Intake Reservoir and Tuolumne River.

Lead In San Francisco Drinking Water

Lead enters tap water through older lead service pipes and lead-containing plumbing. When corrosion control measures put in place by the municipality fail (like what recently happened in Flint, Michigan), lead leaches into the drinking water, and can reach dangerous levels. 10% of samples analyzed for lead are 6 parts per billion in San Francisco drinking water. Though in compliance with federal regulations, EPACDC and American Academy of Pediatrics all acknowledge that there is no safe level of lead for children. 

Chromium 6 In San Francisco Drinking Water

Chromium 6 is a highly toxic metal that is not regulated by the EPA. In recent years, San Francisco’s drinking and tap water has averaged 90 parts per trillion for Chromium 6. For a bit of perspective, Chromium 6 levels in San Francisco's tap water quality are 4.55 times higher than the concentration determined to have negligible impact on cancer risk.

Disinfection Byproducts (DBPs) In San Francisco Drinking Water

DBPs are a category of emerging contaminants that form when chlorine-based disinfectants react with naturally-occurring organic matter. EPA regulates two categories of DBPs: Total Trihalomethanes (TTHMs) and Haloacetic Acids 5 (HAA5). Although these chemicals are not currently regulated very well, EPA discloses that high levels of disinfection byproducts are associated with an increased risk of bladder cancer, as well as kidney, liver, and central nervous system problems.

Chloramine Used To Disinfect San Francisco Drinking Water

While most municipalities use chlorine as the primary disinfectant, San Francisco’s water is disinfected with chloramine (produced by mixing chlorine and ammonia). Chloramine is primarily responsible for what many customers report as the “bad taste” of tap water, and unlike chlorine does not dissipate if a container of water is left in the refrigerator overnight. Most one-size-fits-all water filters use filtration media that doesn’t do a great job removing chloramine, but the filters that we design and build at Hydroviv for San Francisco uses special filtration media that is purposefully designed to remove chloramine as well.

Still Have Questions?

Per and Polyfluoroalkyl Substances (PFAS) are being identified in a growing number of municipalities across the United States. San Francisco has not yet tested for PFAS, but several variations have been detected throughout the state of California. Not all water filters are designed to remove PFAS from drinking water.

Hydroviv is a water filtration company that uses water quality data to optimize water filters for each customer's water. The contaminants that we list above are what we consider to be major “points of emphasis” that we use to build water filters that are built specifically for San Francisco, but all of our filters provide broad protection against a wide range of contaminants.

If you’re interested in learning more about water filters that have been optimized for San Francisco tap water, have questions about our San Francisco water quality report, or questions about water quality in general, feel free to visit, reach out by email ( or through our live chat. We also frequently post water-related news on Twitter or Facebook. We pride ourselves in being a reputable source of information on water quality, and your questions will be answered by scientists, not salespeople (we don't have any salespeople).

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