Is Cottage Lake, WA tap water safe?
The short answer
None of the 4 utilities serving Cottage Lake has a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and Washington’s records.
Woodinville Water District, 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.
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 Cottage Lake’s ZIP codes, from EPA’s estimates.
- Open report
Woodinville Water District
Washington · serves 66,699 people · about 18,200 in Cottage Lake
Nothing in its records is above a health goal.
No health-based violations since 2016
- Open report
City of Redmond Water System
Washington · serves 163,335 people · about 6,500 in Cottage Lake
1 result above EPA’s new limit, which takes effect in 2029 and 2 results above the health goal. The worst: PFOS at 5.0 ppt, above EPA’s new limit, which takes effect in 2029. Hardness: moderately hard, typically 94 mg/L (5.5 grains per gallon).
No health-based violations since 2016
- Open report
Cross Valley Water District
Washington · serves 24,695 people · about 1,300 in Cottage Lake
2 results above the health goal. The worst: Arsenic at 4.7 ppb, above the health goal.
No health-based violations since 2016
- Open report
Crystal Lake Inc
Washington · serves 170 people · about 100 in Cottage Lake
Nothing in its records is above a health goal. Hardness: moderately hard, 83 mg/L (4.8 grains per gallon).
No health-based violations since 2016
Water testing near Cottage Lake
The 3 labs Washington certifies closest to Cottage Lake, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
OnSite Environmental, Inc.
Redmond, WA · about 4 miles
Certified for lead and copper, metals, minerals and other inorganics
Brooks Applied Labs, LLC
Seattle, WA · about 9 miles
Certified for lead and copper, metals
IEH Analytical Laboratories
Seattle, WA · about 9 miles
Certified for nitrate, lead and copper, metals, minerals and other inorganics, PFAS
Which ZIP codes are in Cottage Lake: 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 Cottage Lake
Other towns in King County with a page of their own.
What to do next
- Read Woodinville Water District’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