Is Mercer Island, WA tap water safe?
The short answer
Neither of the 2 utilities serving Mercer Island has a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and Washington’s records.
City of Mercer Island, which serves the most people here, has nothing above a health goal in EPA’s and Washington’s records. That data covers what its report lists, not everything.
The water from City of Mercer Island is moderately hard, 83 mg/L (4.9 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 Mercer Island’s ZIP codes, from EPA’s estimates.
- Open report
City of Mercer Island
Washington · serves 31,057 people · about 25,700 in Mercer Island
Nothing in its records is above a health goal. Hardness: moderately hard, 83 mg/L (4.9 grains per gallon).
No health-based violations since 2016
- Open report
Spring Glen Mobile Home Park
Washington · serves 96 people · based in Mercer Island
2 results above the health goal. The worst: Lead at 6.3 ppb, above the health goal. Hardness: soft, 56 mg/L (3.3 grains per gallon).
No health-based violations since 2016
Water testing near Mercer Island
The 3 labs Washington certifies closest to Mercer Island, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Friedman & Bruya, Inc.
Seattle, WA · about 4 miles
Certified for lead and copper, metals
Seattle-King Co Dept of Public Health Lab
Seattle, WA · about 5 miles
Certified for bacteria
Analytical Resources, LLC
Tukwila, WA · about 6 miles
Certified for nitrate, lead and copper, metals, minerals and other inorganics
ZIP codes in Mercer Island
Which ZIP codes are in Mercer Island: 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 Mercer Island
Other towns in King County with a page of their own.
What to do next
- Read City of Mercer Island’s full reportEvery result with its dates, the violations, and the certification claim that handles each finding.Open the report
- Decide if you want a filter at allA filter for taste or chlorine is a preference, not a need. The standards say what each kind can do.NSF/ANSI standards, decoded
- On a private well?No utility tests a well. A certified lab test is the first step.How to test well water