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Is Napa, CA tap water safe?

11 utilities serve Napa, by EPA’s records. Here is what EPA’s and California’s records show for each, against the legal limits and the stricter health goals.

Matched to your utility using EPA records.

The short answer

10 of the 11 utilities serving Napa have a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and California’s records: City of Napa, Berryessa Highlands, Meyers Water Co. and 7 more.

City of Napa, which serves the most people here, has 2 results above the health goal. The worst: Arsenic at 3.0 ppb, above the health goal. Health goals are stricter than legal limits and are not enforced.

The water from City of Napa is soft to hard depending on the source, 30 to 159 mg/L (1.8 to 9.3 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 Napa’s ZIP codes, from EPA’s estimates.

1 more utility in Napa

By EPA’s estimate, each serves fewer people in Napa than those above.

  • Hess Wineryserves 100 people · based in Napa · 1 health-based violation since 2016

What handles it

Each of these is certified, on a certifier’s listing, for a result above a line in City of Napa’s water, which serves the most people here. Another utility’s report names what handles its own results.

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Every claim, and more filters, in the full report

Water testing near Napa

A utility tests the water it sends out. A test of your own tap shows what your pipes add, and on a private well it is the only test there is. It takes a lab California certifies.

The 3 labs California certifies closest to Napa, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Caltest Analytical Laboratory

    Napa, CA · about 7 miles

    Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts

    (707) 258-4000

  • Napa-Solano-Yolo-Marin Public Health Laboratory

    Fairfield, CA · about 13 miles

    Certified for bacteria

    (707) 784-4410

  • Alpha Analytical Laboratories Inc. - North Bay

    Petaluma, CA · about 21 miles

    Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, PFAS

    (707) 769-3128

All 145 certified labs for California

ZIP codes in Napa

Which ZIP codes are in Napa: 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 Napa

Other towns in Napa County with a page of their own.

What to do next