Is San Diego, CA tap water safe?
The short answer
1 of the 5 utilities serving San Diego has a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and California’s records: Cal - Am Water Coronado.
City of San Diego, which serves the most people here, has 1 result above the limit’s level with no violation recorded, 1 result above the health goal and 1 result above EPA’s health benchmark. The worst: Uranium at 44.7 ppb, above the limit’s level, no violation. Health goals are stricter than legal limits and are not enforced.
The water from City of San Diego is moderately hard to very hard depending on the source, 113 to 619 mg/L (6.6 to 36.2 grains per gallon). How California’s water compares.
A town can be served by more than one utility, and some homes are on private wells. The name on your water bill tells you which is yours, and your ZIP code narrows it down. They are listed by how many people each serves in San Diego’s ZIP codes, from EPA’s estimates.
- Open report
City of San Diego
California · serves 1.4 million people · nearly all in San Diego
1 result above the limit’s level with no violation recorded, 1 result above the health goal and 1 result above EPA’s health benchmark. The worst: Uranium at 44.7 ppb, above the limit’s level, no violation. Hardness: moderately hard to very hard depending on the source, 113 to 619 mg/L (6.6 to 36.2 grains per gallon).
No health-based violations since 2016
- Open report
Cal - Am Water Coronado
California · serves 106,000 people · about 26,900 in San Diego
1 result above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 65.5 ppb, above EPA’s health benchmark.
1 health-based violation since 2016
- Open report
Padre Dam MWD
California · serves 93,980 people · about 12,000 in San Diego
1 result above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 47 ppb, above EPA’s health benchmark.
No health-based violations since 2016
- Open report
Olivenhain MWD
California · serves 86,458 people · about 11,400 in San Diego
2 results above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 54.1 ppb, above EPA’s health benchmark. Hardness: very hard, typically 227 mg/L (13.3 grains per gallon).
No health-based violations since 2016
- Open report
City of Escondido
California · serves 137,044 people · about 11,100 in San Diego
3 results above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 30 ppb, above EPA’s health benchmark. Hardness: hard to very hard depending on the source, 150 to 255 mg/L (8.8 to 14.9 grains per gallon).
No health-based violations since 2016
What handles it
Each of these is certified, on a certifier’s listing, for a result above a line in City of San Diego’s water, which serves the most people here. Another utility’s report names what handles its own results.
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Countertop reverse osmosis
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 4, 2026
Certified for: Arsenic
Aquasana SmartFlow Reverse Osmosis (AQ-SFRO2)
Under-sink reverse osmosis
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 9, 2026
Certified for: Arsenic
Brondell Capella RC250 Reverse Osmosis System
Under-sink reverse osmosis
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 9, 2026
Certified for: Arsenic
Water testing near San Diego
The 3 labs California certifies closest to San Diego, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Analytical Environmental Lab, LLC
San Diego, CA · about 2 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, disinfection byproducts
EMSL Analytical, Inc.
San Diego, CA · about 2 miles
Certified for bacteria
Environmental Laboratory Network, Inc.
San Diego, CA · about 3 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, radioactivity
ZIP codes in San Diego
Which ZIP codes are in San Diego: Census 2020 relationship files. Which utilities serve them, and how many people: EPA SDWIS and EPA’s service area map. Each utility’s results: EPA UCMR 5, EPA SDWIS, and EPA’s and the state’s compliance monitoring, as its report lists them. How they are measured: methodology. Certified labs: California State Water Resources Control Board, ELAP accredited laboratories and their fields of accreditation; distances from the Census 2020 ZIP code tabulation area gazetteer.
Near San Diego
Other towns in San Diego County with a page of their own.
What to do next
- Read City of San Diego’s full reportEvery result with its dates, the violations, and the certification claim that handles each finding.Open the report
- About UraniumWhat it does to health, where it comes from, and the certification claim that addresses it.About Uranium
- On a private well?No utility tests a well. A certified lab test is the first step.How to test well water