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Oysterville Water

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
72 people
Connections
76
Water source
Groundwater
Based in
Oysterville, WA
County
Pacific
Owner
Private
The ZIP code it serves

98641

The short answer

2 results are above EPA’s legal limit, and 2 more are above the health goal. The worst: Haloacetic acids (HAA5), above the legal limit. 9 health-based violations since 2016.

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 2009 to 2024.

Haloacetic acids (HAA5), total trihalomethanes (TTHM) and nitrate: Washington’s own results, samples taken from March 11, 2020 to Sept. 30, 2025, with EPA’s 2012 to 2019 file for earlier years.

Arsenic, chromium (total) and fluoride: EPA’s compliance monitoring file, samples taken from Oct. 1, 2019 to Oct. 1, 2019. Newer results are in the utility’s annual water quality report.

Above the legal limit2

Haloacetic acids (HAA5)

Forms or is added in treatment

Above the legal limit

52.3ppb

Highest yearly average, 2020 to 2025

2025, one sample: 22.8 ppb

Averaged by year, the highest was 52.3 ppb, in 2021, below EPA’s legal limit of 60 ppb. Its highest single sample was 73 ppb. In 2025, the latest year on file, its one sample was 22.8 ppb. EPA judges this limit at each sampling point, and recorded a violation for haloacetic acids (HAA5) at this utility in 2020. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 102 ppb, in 2019, and EPA recorded a violation in 2019.

What handles it

No certification claim covers this compound yet.

Total trihalomethanes (TTHM)

Forms or is added in treatment

Above the legal limit

56.9ppb

Highest yearly average, 2020 to 2025

2025, one sample: 46.4 ppb

Averaged by year, the highest was 56.9 ppb, in 2020, below EPA’s legal limit of 80 ppb. Its highest single sample was 72.1 ppb. In 2025, the latest year on file, its one sample was 46.4 ppb. EPA judges this limit at each sampling point, and recorded a violation for total trihalomethanes (TTHM) at this utility in 2020. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 93.2 ppb, in 2019, and EPA recorded a violation in 2019.

What handles it

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

Above the health goal2

Arsenic

Comes from the source

Above the health goal

3.2ppb

Highest yearly average, 2019

Averaged by year, the highest was 3.2 ppb, in 2019: below EPA’s legal limit of 10 ppb, but above its health goal of zero. That is the only year on file.

What handles it

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

Lead

Comes from pipes, often your own

Above the health goal

4.0ppb

90th percentile, 2022 to 2024

In the latest period, 9 in 10 homes sampled were at or below 4.0 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 limits1

Nitrate

Comes from the source

Below EPA’s limits

1.4ppm

Highest sample; found in 6 of 6

2025, one sample: 1.0 ppm

The highest sample, in 2022, was 1.4 ppm, below EPA’s legal limit of 10 ppm. In 2025, the latest year on file, its one sample was 1.0 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 1.1 ppm, in 2018.

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.
  • Chromium (total)
  • Fluoride

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, Arsenic (Pentavalent)<=50 ppb Reduction, Lead Reduction

    For: Total trihalomethanes (TTHM), Arsenic, Lead

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

  • NSF/ANSI 58

    Claims: Trihalomethanes (TTHM) Reduction, Arsenic (Pentavalent)<=50 ppb Reduction, Lead Reduction

    For: Total trihalomethanes (TTHM), Arsenic, Lead

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

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 reverse osmosis systems, ranked

The best water filters for lead, ranked

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
Total Haloacetic Acids (HAA5)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2020 to Sept. 30, 202072.7 UG/LResolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2020 to June 30, 202084.2 UG/LResolved
Total Haloacetic Acids (HAA5)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2020 to June 30, 202095.4 UG/LResolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2020 to March 31, 202088.2 UG/LResolved
Total Haloacetic Acids (HAA5)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2020 to March 31, 2020100 UG/LResolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2019 to Dec. 31, 201993.2 UG/LResolved
Total Haloacetic Acids (HAA5)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2019 to Dec. 31, 2019102 UG/LResolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2019 to Sept. 30, 201986.8 UG/LResolved
Total Haloacetic Acids (HAA5)The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2019 to Sept. 30, 201980.1 UG/LResolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record.

What this report can’t tell you

  • Everything else. Haloacetic acids (HAA5), total trihalomethanes (TTHM) and nitrate results here are Washington’s own from 2020 on, with EPA’s national file for 2012 to 2019. Arsenic, chromium (total) and fluoride come from EPA’s file alone, which ends in 2019. Oysterville Water’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 March 11, 2020 to Sept. 30, 2025; EPA’s compliance samples are from Oct. 1, 2019 to Oct. 1, 2019.

Testing your own tap

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

  • Pacific County DCD WQ Laboratory

    South Bend, WA · about 9 miles

    Certified for bacteria

    (360) 875-9356

  • Lewis County Environmental Health Laboratory

    Chehalis, WA · about 47 miles

    Certified for bacteria, nitrate

    (360) 740-1237

  • Grays Harbor County Water Testing Lab

    Montesano, WA · about 49 miles

    Certified for bacteria, nitrate

    (360) 249-4413

All 84 certified labs for Washington

Sources

PWSID WA5329240. Rebuilt from EPA data on Oct. 18, 2026.

Also in Pacific County

All Washington utilities

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