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Weott C.S.D.

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
448 people
Connections
136
Water source
Surface water
Based in
Weott, CA
County
Humboldt
Owner
Local government
Hardness
Moderately hard
The ZIP code it serves

95571

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. 1 health-based violation since 2016.

What was found

Total trihalomethanes (TTHM), haloacetic acids (HAA5), arsenic, chromium (total) and nitrate: California’s own results, samples taken from April 28, 2020 to Dec. 4, 2025, with EPA’s 2012 to 2019 file for earlier years.

Fluoride: EPA’s compliance monitoring file, samples taken from Sept. 13, 2016 to Sept. 13, 2016. Newer results are in the utility’s annual water quality report.

Below EPA’s limits3

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

13.4ppb

Highest yearly average, 2021 to 2025

2025 average: 11.8 ppb

Averaged by year, the highest was 13.4 ppb, in 2021, below EPA’s legal limit of 80 ppb. Its highest single sample was 28 ppb. In 2025, the latest year on file, its four samples averaged 11.8 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 9.7 ppb, in 2019.

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

Below EPA’s limits

5.3ppb

Highest yearly average, 2021 to 2025

Averaged by year, the highest was 5.3 ppb, in 2025, below EPA’s legal limit of 60 ppb. Its highest single sample was 21 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 2.3 ppb, in 2019.

What handles it

No certification claim covers this compound yet.

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.11ppm

Highest yearly average, 2016

Averaged by year, the highest was 0.11 ppm, in 2016, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 0.12 ppm. That is the only year on file.

What handles it

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

Hardness

Moderately hard, typically 89 mg/L (5.2 grains per gallon), across 2 sampling points, in 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 5.2 grains per gallon, salt includedSoftener or salt-free conditioner?California water hardness, utility by utility

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
Interim Enhanced Surface Water Treatment RuleToo many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR)May 1, 2022 to May 31, 2022—Archived
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 6 monitoring or reporting violations not shown.

What this report can’t tell you

  • Everything else. Total trihalomethanes (TTHM), haloacetic acids (HAA5), arsenic, chromium (total) and nitrate results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. Fluoride comes from EPA’s file alone, which ends in 2019. Weott C.S.D.’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; California’s results run from April 28, 2020 to Dec. 4, 2025; EPA’s compliance samples are from Sept. 13, 2016 to Sept. 13, 2016.

Testing your own tap

Weott C.S.D.’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 2 labs California certifies closest to the area Weott C.S.D. serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Humboldt County Public Health Laboratory

    Eureka, CA · about 35 miles

    Certified for bacteria

    (707) 268-2179

  • Microbac Laboratories, Inc. - Arcata

    Arcata, CA · about 41 miles

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

    (707) 822-4649

All 145 certified labs for California

Sources

PWSID CA1200553. Rebuilt from EPA data on Oct. 18, 2026.

Also in Humboldt County

All California utilities

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