Skip to content
TapBuff
ZIP

Is Oakley, CA tap water safe?

7 utilities serve Oakley, 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

3 of the 7 utilities serving Oakley have a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and California’s records: Willow Park Marina, Delta Mutual Water Company and Oakley Mutual Water Company.

Diablo Water District, which serves the most people here, has 3 results above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 15 ppb, above EPA’s health benchmark. Health goals are stricter than legal limits and are not enforced.

The water from Diablo Water District is moderately hard to very hard depending on the source, 92 to 330 mg/L (5.4 to 19.3 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 Oakley’s ZIP codes, from EPA’s estimates.

What handles it

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

Disclosure: TapBuff earns a commission if you buy through some links on this page. It does not change which standard or filter we name. As an Amazon Associate, TapBuff earns from qualifying purchases. How TapBuff makes money

Every claim, and more filters, in the full report

Water testing near Oakley

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 Oakley, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • McCampbell Analytical, Inc.

    Pittsburg, CA · about 13 miles

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

    (925) 252-9262

  • Precision Enviro-Tech

    Stockton, CA · about 22 miles

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

    (209) 405-0601

  • Alpha Analytical Laboratories, Inc.

    Livermore, CA · about 23 miles

    Certified for bacteria

    (707) 769-3128

All 145 certified labs for California

ZIP codes in Oakley

Which ZIP codes are in Oakley: 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 Oakley

Other towns in Contra Costa County with a page of their own.

What to do next