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Sierra Country Club

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
400 people
Connections
234
Water source
Groundwater
Based in
Coupeville, WA
County
Island
Owner
Private
Hardness
Very hard
The ZIP code it serves

98239

The short answer

2 results are above EPA’s legal limit, and 1 more is above the health goal. The worst: Total trihalomethanes (TTHM), above the legal limit. 9 health-based violations since 2016.

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 2001 to 2023.

Copper: EPA’s file records a utility’s copper only when it exceeds the action level. The last here was 1.4 ppm, for the period ending Dec. 31, 2011. None since is on file, so it is not counted as a current finding.

Total trihalomethanes (TTHM), haloacetic acids (HAA5) and nitrate: Washington’s own results, samples taken from Sept. 30, 2020 to Sept. 21, 2026, with EPA’s 2012 to 2019 file for earlier years.

Fluoride, arsenic and chromium (total): EPA’s compliance monitoring file, samples taken from Aug. 24, 2016 to Aug. 24, 2016. Newer results are in the utility’s annual water quality report.

Above the legal limit2

Total trihalomethanes (TTHM)

Forms or is added in treatment

Above the legal limit

207ppb

Highest yearly average, 2021 to 2026

2026 average: 121 ppb

Averaged by year, the highest was 207 ppb, in 2023, about 2.6 times EPA’s legal limit of 80 ppb. Its highest single sample was 229 ppb. In 2026, the latest year on file, its three samples averaged 121 ppb, above the limit. EPA recorded violations for total trihalomethanes (TTHM) at this utility in 2023 and 2024. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 110 ppb, in 2015.

What handles it

  • NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
  • NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”

Haloacetic acids (HAA5)

Forms or is added in treatment

Above the legal limit

118ppb

Highest yearly average, 2021 to 2026

2026 average: 65 ppb

Averaged by year, the highest was 118 ppb, in 2023, about twice EPA’s legal limit of 60 ppb. Its highest single sample was 143 ppb. In 2026, the latest year on file, its three samples averaged 65 ppb, above the limit. EPA recorded violations for haloacetic acids (HAA5) at this utility in 2023 and 2024. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 83.8 ppb, in 2013.

What handles it

No certification claim covers this compound yet.

Above the health goal1

Lead

Comes from pipes, often your own

Above the health goal

1.5ppb

90th percentile, 2021 to 2023

In the latest period, 9 in 10 homes sampled were at or below 1.5 ppb, below EPA’s action level of 15 ppb. The action level drops to 10 ppb on Nov. 1, 2027. EPA’s health goal for lead is zero.

What handles it

Below EPA’s limits2

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.9ppm

Highest yearly average, 2016

Averaged by year, the highest was 0.9 ppm, in 2016, below EPA’s legal limit of 4.0 ppm. That is the only year on file.

What handles it

Nitrate

Comes from the source

Below EPA’s limits

0.13ppm

Highest sample; found in 1 of 15

2026: not found

The highest sample, in 2024, was 0.13 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, it wasn’t found in any of its two samples.

What handles it

  • NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
  • NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
2 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Arsenic
  • Chromium (total)

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

    Claims: Trihalomethanes (TTHM) Reduction, Lead Reduction

    For: Total trihalomethanes (TTHM), Lead

    Other certifiers’ wording: VOC Reduction

  • NSF/ANSI 58

    Claims: Trihalomethanes (TTHM) Reduction, Lead Reduction

    For: Total trihalomethanes (TTHM), Lead

At the tap, or for the whole house?

Lead and copper usually come from pipes and fixtures inside or near your home. A whole-house system sits where water enters, so it cannot catch what your own plumbing adds after it. For those, the filter that counts is the one at the tap. 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 water filters for lead, ranked

Hardness

Very hard, typically 285 mg/L (16.7 grains per gallon), across 2 sampling points, 2021 to 2025.

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 at 16.7 grains per gallon, salt includedSoftener or salt-free conditioner?Washington water hardness, utility by utility

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
Total Haloacetic Acids (HAA5)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2024 to Dec. 31, 202461.1 UG/LArchived
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2024 to Sept. 30, 202494.8 UG/LArchived
Total Haloacetic Acids (HAA5)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2024 to Sept. 30, 202485 UG/LArchived
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2024 to June 30, 2024229 UG/LArchived
Total Haloacetic Acids (HAA5)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2024 to June 30, 2024116 UG/LArchived
Total Haloacetic Acids (HAA5)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2024 to March 31, 2024118 UG/LArchived
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2024 to March 31, 2024207 UG/LArchived
Total Haloacetic Acids (HAA5)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2023 to Dec. 31, 2023118 UG/LArchived
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2023 to Dec. 31, 2023207 UG/LArchived
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 2 monitoring or reporting violations not shown.

What this report can’t tell you

  • Everything else. Total trihalomethanes (TTHM), haloacetic acids (HAA5) and nitrate results here are Washington’s own from 2020 on, with EPA’s national file for 2012 to 2019. Fluoride, arsenic and chromium (total) come from EPA’s file alone, which ends in 2019. Sierra Country Club’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 Sept. 30, 2020 to Sept. 21, 2026; EPA’s compliance samples are from Aug. 24, 2016 to Aug. 24, 2016.

Testing your own tap

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

  • Precision Analytical Laboratories, LLC

    Everett, WA · about 24 miles

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

    (425) 740-4597

  • Eurofins DW and WW West, Washington Laboratory

    Burlington, WA · about 25 miles

    Certified for bacteria, nitrate, minerals and other inorganics, disinfection byproducts

    (360) 757-1400

  • Everett Environmental Laboratory

    Everett, WA · about 27 miles

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

    (425) 257-8230

All 84 certified labs for Washington

Sources

PWSID WA5378975. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Island County

All Washington utilities

What to do next