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Miller Bay

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
1,072 people
Connections
430
Water source
Groundwater
Based in
Poulsbo, WA
County
Kitsap
Owner
Local government
Hardness
Moderately hard
The ZIP code it serves

98370

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

Haloacetic acids (HAA5), total trihalomethanes (TTHM), arsenic, chromium (total), fluoride and nitrate: Washington’s own results, samples taken from Aug. 21, 2020 to June 25, 2026, with EPA’s 2012 to 2019 file for earlier years.

Uranium: EPA’s compliance monitoring file, samples taken from Dec. 14, 2016 to Dec. 14, 2016. Newer results are in the utility’s annual water quality report.

Below EPA’s limits2

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

10.0ppb

Highest yearly average, 2020 to 2025

Averaged by year, the highest was 10.0 ppb, in 2025, below EPA’s legal limit of 60 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 9.1 ppb, in 2015.

What handles it

No certification claim covers this compound yet.

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

13.1ppb

Highest yearly average, 2020 to 2025

Averaged by year, the highest was 13.1 ppb, in 2025, below EPA’s legal limit of 80 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 19.4 ppb, in 2015.

What handles it

  • NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
  • NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”
6 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Arsenic
  • Chromium (total)
  • Fluoride
  • Lead
  • Nitrate
  • Uranium

Hardness

Moderately hard, typically 114 mg/L (6.6 grains per gallon), across 2 sampling points, in 2021.

Hardness is calcium and magnesium. EPA sets no limit for it: it shows up as scale on fixtures and in water heaters, and as soap that won’t lather. USGS calls water above 60 mg/L moderately hard, above 120 hard and above 180 very hard.

Violations since 2016

No health-based violations on file with EPA since 2016. There is 1 monitoring or reporting violation: a sample missed, late or not reported.

What this report can’t tell you

  • Everything else. Haloacetic acids (HAA5), total trihalomethanes (TTHM), arsenic, chromium (total), fluoride and nitrate results here are Washington’s own from 2020 on, with EPA’s national file for 2012 to 2019. Uranium comes from EPA’s file alone, which ends in 2019. Miller Bay’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 Aug. 21, 2020 to June 25, 2026; EPA’s compliance samples are from Dec. 14, 2016 to Dec. 14, 2016.

Testing your own tap

Miller Bay’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 Miller Bay serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Spectra Laboratories - Kitsap, LLC

    Poulsbo, WA · under a mile

    Certified for bacteria, nitrate, minerals and other inorganics

    (360) 779-5141

  • Eurofins EPK Built Environment Testing, LLC

    Seattle, WA · about 12 miles

    Certified for bacteria, asbestos

    (206) 781-0155

  • Alliance Technical Group, LLC-Seattle

    Seattle, WA · about 14 miles

    Certified for bacteria, lead and copper, metals

    (206) 352-3790

All 84 certified labs for Washington

Sources

PWSID WA5354683. Rebuilt from EPA data on Oct. 18, 2026.