Skip to content
TapBuff
ZIP

Is Issaquah, WA tap water safe?

12 utilities serve Issaquah, by EPA’s records. Here is what EPA’s and Washington’s records show for each, against the legal limits and the stricter health goals.

Matched to your utility using EPA records.

The short answer

1 of the 12 utilities serving Issaquah has a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and Washington’s records: Issaquah Valley Water Assn #1.

Sammamish Plateau Water & Sewer, which serves the most people here, has 2 results above EPA’s new limit, which takes effect in 2029 and 2 results above the health goal. The worst: PFOS at 11.1 ppt, above EPA’s new limit, which takes effect in 2029.

The water from Sammamish Plateau Water & Sewer is soft to moderately hard depending on the source, 51 to 95 mg/L (3 to 5.6 grains per gallon). How Washington’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 Issaquah’s ZIP codes, from EPA’s estimates.

2 more utilities in Issaquah

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

  • Alpine Mobile Manorserves 45 people · under 100 in Issaquah · no health-based violations since 2016
  • Tiger Mtn Tractsserves 30 people · based in Issaquah · 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 Sammamish Plateau Water & Sewer’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 Issaquah

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 Washington certifies.

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

  • Aqua Test, Incorporated

    Maple Valley, WA · about 8 miles

    Certified for bacteria, nitrate

    (425) 432-9360

  • AmTest Laboratories

    Renton, WA · about 11 miles

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

    (425) 885-1664

  • OnSite Environmental, Inc.

    Redmond, WA · about 12 miles

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

    (425) 883-3881

All 84 certified labs for Washington

ZIP codes in Issaquah

Which ZIP codes are in Issaquah: 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: Washington State Department of Ecology, Lab Accreditation Program, environmental laboratories accredited for drinking water analyses; distances from the Census 2020 ZIP code tabulation area gazetteer.

Near Issaquah

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

What to do next