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Fox Island Mutual Water Assoc

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
3,255 people
Connections
1,396
Water source
Groundwater
Based in
Fox Island, WA
County
Pierce
Owner
Private
Hardness
Varies by source
The ZIP code it serves

98333

The short answer

1 result is above the health goal. The worst: Arsenic, above the health goal. No health-based violations on file since 2016.

What handles it

What was found

Copper: EPA’s file records a utility’s copper only when it exceeds the action level. The last here was 1.8 ppm, for the period ending Dec. 31, 1993. None since is on file, so it is not counted as a current finding.

Arsenic, nitrate, haloacetic acids (HAA5), total trihalomethanes (TTHM), chromium (total) and fluoride: Washington’s own results, samples taken from April 8, 2020 to Aug. 5, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the health goal1

Arsenic

Comes from the source

Above the health goal

2.0ppb

Highest yearly average, 2021 to 2026

2026 average: 1.4 ppb

Averaged by year, the highest was 2.0 ppb, in 2025: below EPA’s legal limit of 10 ppb, but above its health goal of zero. Its highest single sample was 2.7 ppb. In 2026, the latest year on file, its two samples averaged 1.4 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 4.0 ppb, in 2018.

What handles it

  • NSF/ANSI 58 look for “Arsenic (Pentavalent)<=50 ppb Reduction”
  • NSF/ANSI 53 look for “Arsenic (Pentavalent)<=50 ppb Reduction”

Below EPA’s limits3

Nitrate

Comes from the source

Below EPA’s limits

4.4ppm

Highest sample; found in 28 of 59

2026 average: 1.2 ppm

The highest sample, in 2020, was 4.4 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, its nine samples averaged 1.2 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 3.7 ppm, in 2017.

What handles it

  • NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
  • NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

8.8ppb

Highest yearly average, 2020 to 2025

2025 average: 4.6 ppb

Averaged by year, the highest was 8.8 ppb, in 2024, below EPA’s legal limit of 60 ppb. Its highest single sample was 12 ppb. In 2025, the latest year on file, its two samples averaged 4.6 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 7.3 ppb, in 2017.

What handles it

No certification claim covers this compound yet.

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

9.0ppb

Highest yearly average, 2020 to 2025

2025 average: 6.0 ppb

Averaged by year, the highest was 9.0 ppb, in 2024, below EPA’s legal limit of 80 ppb. Its highest single sample was 11.8 ppb. In 2025, the latest year on file, its two samples averaged 6.0 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 9.4 ppb, in 2015.

What handles it

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

What handles it

A certification covers specific claims, not a whole standard. Look for these claims on the certifier’s listing, not the box. Wording varies a little: NSF writes “Lead Reduction,” WQA just “Lead.”

  • NSF/ANSI 53

    Claim: Arsenic (Pentavalent)<=50 ppb Reduction

    For: Arsenic

    Other certifiers’ wording: Arsenic (III) (50 ppb influent level)

  • NSF/ANSI 58

    Claim: Arsenic (Pentavalent)<=50 ppb Reduction

    For: Arsenic

    Other certifiers’ wording: Arsenic (Pentavalent)<=300 ppb Reduction; Arsenic (V) (300 ppb influent level)

At the tap, or for the whole house?

These come with the water itself, so a whole-house system certified for the same claims treats every tap and shower. A filter at the tap treats drinking water for much less. How whole-house systems compare.

Filters with those claims on a certifier’s listing

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

Compare five-year costs

The best reverse osmosis systems, ranked

Hardness

Soft to moderately hard depending on the source, 59 to 110 mg/L (3.5 to 6.4 grains per gallon), across 6 sampling points, 2021 to 2026.

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.

Softeners compared, salt includedSoftener or salt-free conditioner?Washington water hardness, utility by utility

Violations since 2016

No health-based violations on file with EPA since 2016.

What this report can’t tell you

  • Everything else. Arsenic, nitrate, haloacetic acids (HAA5), total trihalomethanes (TTHM), chromium (total) and fluoride results here are Washington’s own from 2020 on, with EPA’s national file for 2012 to 2019. Fox Island Mutual Water Assoc’s own annual report, which it must send you every year, has 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 April 8, 2020 to Aug. 5, 2026.

Testing your own tap

Fox Island Mutual Water Assoc’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 Fox Island Mutual Water Assoc serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Water Management Laboratories, Inc.

    Tacoma, WA · about 12 miles

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

    (253) 531-3121

  • Thurston County Health Department Laboratory

    Olympia, WA · about 15 miles

    Certified for bacteria, nitrate

    (360) 867-2631

  • Olympic Analytical LLC dba Vanguard Laboratory

    Olympia, WA · about 21 miles

    Certified for bacteria, nitrate

    (360) 967-7010

All 84 certified labs for Washington

Sources

PWSID WA5326300. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Pierce County

All Washington utilities

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