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Sunset Domestic Water Assn

What EPA’s and Washington’s records show in this utility’s water: nitrate, arsenic and other regulated chemicals; lead and copper; and violations since 2016, with the certification that handles each result.

Serves
60 people
Connections
20
Water source
Groundwater
Based in
Pasco, WA
County
Franklin
Owner
Private
The ZIP code it serves

99301

The short answer

Nothing in EPA’s and Washington’s records for this utility is above a health goal. That covers nitrate, arsenic and other regulated chemicals, plus lead and copper, not everything. No health-based violations on file since 2016.

What was found

Fluoride, chromium (total) and nitrate: Washington’s own results, samples taken from June 25, 2020 to Sept. 25, 2025, with EPA’s 2012 to 2019 file for earlier years.

Arsenic: EPA’s compliance monitoring file, samples taken from July 15, 2013 to June 25, 2014. Newer results are in the utility’s annual water quality report.

Below EPA’s limits1

Fluoride

Forms or is added in treatment

Below EPA’s limits

1.1ppm

Highest yearly average, 2020

Averaged by year, the highest was 1.1 ppm, in 2020, below EPA’s legal limit of 4.0 ppm. That is the only year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 1.1 ppm, in 2014.

What handles it

4 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Arsenic
  • Chromium (total)
  • Lead
  • Nitrate

Violations since 2016

No health-based violations on file with EPA since 2016. There are 21 monitoring or reporting violations: a sample missed, late or not reported.

What this report can’t tell you

  • Everything else. Fluoride, chromium (total) and nitrate results here are Washington’s own from 2020 on, with EPA’s national file for 2012 to 2019. Arsenic comes from EPA’s file alone, which ends in 2019. Sunset Domestic Water Assn’s own annual report, which it must send you every year, has newer results for those and the contaminants this page does not show.

  • Your own plumbing. Lead results are the 90th percentile across homes the utility samples. Your home’s service line, solder and fixtures decide yours. A certified lab test is the only way to know.

  • What it means for your health. This page reports what the records show and EPA’s limits and goals; it is not medical advice. If you are worried about a health effect, talk to a doctor or your local health department.

  • Anything after the latest data. SDWIS data is from 2026 Q3; UCMR 5 didn’t sample this utility; Washington’s results run from June 25, 2020 to Sept. 25, 2025; EPA’s compliance samples are from July 15, 2013 to June 25, 2014.

Testing your own tap

Sunset Domestic Water Assn’s results are for the water it sends out. What your own service line, solder and fixtures add shows up only in a test of your tap, by a lab Washington certifies.

The 3 labs Washington certifies closest to the area Sunset Domestic Water Assn serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Matrix Sciences International Inc. dba KTL

    Pasco, WA · under a mile

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

    (509) 547-3838

  • RJ Lee Group, Inc. Columbia Basin Analytical Laboratories

    Pasco, WA · under a mile

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

    (509) 792-1951

  • Benton-Franklin Health District Lab

    Kennewick, WA · about 16 miles

    Certified for bacteria, nitrate, minerals and other inorganics

    (509) 460-4206

All 84 certified labs for Washington

Sources

PWSID WA5386100. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Franklin County

All Washington utilities

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