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Is Boulder, CO tap water safe?

10 utilities serve Boulder, by EPA’s records. Here is what EPA’s and Colorado’s records show for each, against the legal limits and the stricter health goals.

Matched to your utility using EPA records.

The short answer

4 of the 10 utilities serving Boulder have a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and Colorado’s records: City of Boulder, Sans Souci Cooperative, Spring Valley Mutual WA and 1 more.

City of Boulder, which serves the most people here, has 1 result above the health goal. The worst: Lead at 2.0 ppb, above the health goal. Health goals are stricter than legal limits and are not enforced.

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 Boulder’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 City of Boulder’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 Boulder

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 Colorado certifies.

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

  • Hazen Research

    Golden, CO · about 12 miles

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

  • Eurofins Denver

    Arvada, CO · about 17 miles

    Certified for nitrate, minerals and other inorganics, organic chemicals, PFAS

  • Eurofins Reservoirs Environmental, Inc.

    Arvada, CO · about 17 miles

    Certified for bacteria

All 54 certified labs for Colorado

ZIP codes in Boulder

Which ZIP codes are in Boulder: 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: CDPHE certified drinking water laboratories; distances from the Census 2020 ZIP code tabulation area gazetteer.

Near Boulder

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

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