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Westport County Water District

What EPA’s and California’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
70 people
Connections
78
Water source
Surface water
Based in
Westport, CA
County
Mendocino
Owner
Private
Hardness
Varies by source
The ZIP code it serves

95488

The short answer

Nothing in EPA’s and California’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

Copper: EPA’s file records a utility’s copper only when it exceeds the action level. The last here was 1.5 ppm, for the period ending June 30, 2013. None since is on file, so it is not counted as a current finding.

Haloacetic acids (HAA5), total trihalomethanes (TTHM), fluoride, arsenic, chromium (total), nitrate and uranium: California’s own results, samples taken from Aug. 12, 2020 to March 24, 2026, with EPA’s 2012 to 2019 file for earlier years.

Below EPA’s limits3

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

5.1ppb

Highest yearly average, 2020 to 2025

2025: not found

Averaged by year, the highest was 5.1 ppb, in 2020, below EPA’s legal limit of 60 ppb. In 2025, the latest year on file, it wasn’t found in its one sample. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 11.9 ppb, in 2013.

What handles it

No certification claim covers this compound yet.

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

6.5ppb

Highest yearly average, 2020 to 2026

2026: not found

Averaged by year, the highest was 6.5 ppb, in 2023, below EPA’s legal limit of 80 ppb. In 2026, the latest year on file, it wasn’t found in its one sample. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 22.7 ppb, in 2014.

What handles it

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

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.12ppm

Highest yearly average, 2020 to 2025

2025, one sample: 0.12 ppm

Averaged by year, the highest was 0.12 ppm, in 2020, below EPA’s legal limit of 4.0 ppm. In 2025, the latest year on file, its one sample was 0.12 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.23 ppm, in 2019.

What handles it

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

Hardness

Moderately hard to hard depending on the source, 69 to 135 mg/L (4 to 7.9 grains per gallon), across 2 sampling points, 2019 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, salt includedSoftener or salt-free conditioner?California water hardness, utility by utility

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), fluoride, arsenic, chromium (total), nitrate and uranium results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. Westport County Water District’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; California’s results run from Aug. 12, 2020 to March 24, 2026.

Testing your own tap

Westport County Water District’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 California certifies.

The lab California certifies closest to the area Westport County Water District serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Alpha Analytical Laboratories, Inc. - Ukiah

    Ukiah, CA · about 47 miles

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

    (707) 468-0401

All 145 certified labs for California

Sources

PWSID CA2300730. Rebuilt from EPA data on Oct. 18, 2026.

Also in Mendocino County

All California utilities

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