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Is Ontario, CA tap water safe?

3 utilities serve Ontario, 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

None of the 3 utilities serving Ontario has a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and California’s records.

Ontario Municipal Utilities Company, which serves the most people here, has 2 results above EPA’s new limit, which takes effect in 2029 and 3 results above the health goal. The worst: PFOA at 30 ppt, above EPA’s new limit, which takes effect in 2029.

The water from Ontario Municipal Utilities Company is moderately hard to very hard depending on the source, 83 to 190 mg/L (4.8 to 11.1 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 Ontario’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 Ontario Municipal Utilities Company’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 Ontario

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

  • A & R Laboratories, Inc.

    Ontario, CA · about 1 mile

    Certified for bacteria

    (951) 779-0310

  • Western Analytical Laboratories, Inc.

    Chino, CA · about 6 miles

    Certified for bacteria, minerals and other inorganics

    (909) 627-3628

  • Enviro-Chem, Inc.

    Pomona, CA · about 6 miles

    Certified for metals

    (909) 590-5905

All 145 certified labs for California

ZIP codes in Ontario

Which ZIP codes are in Ontario: 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 Ontario

Other towns in San Bernardino County with a page of their own.

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