Skip to content
TapBuff
ZIP

South Cloverdale Water Company

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
90 people
Connections
36
Water source
Groundwater
Based in
Cloverdale, CA
County
Sonoma
Owner
Private
Hardness
Very hard

The short answer

1 result is above EPA’s legal limit. The worst: Copper, above the action level. 1 health-based violation since 2016.

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 2021 to 2026.

Total trihalomethanes (TTHM), nitrate, fluoride, chromium (total), arsenic and haloacetic acids (HAA5): California’s own results, samples taken from Feb. 26, 2020 to Sept. 25, 2025, with EPA’s 2012 to 2019 file for earlier years.

Above the legal limit1

Copper

Comes from pipes, often your own

Above the action level

1.4ppm

90th percentile, 2026

In the latest period, 9 in 10 homes sampled were at or below 1.4 ppm, above EPA’s action level of 1.3 ppm.

What handles it

Below EPA’s limits4

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

17ppb

Highest yearly average, 2022 to 2025

Averaged by year, the highest was 17 ppb, in 2025, below EPA’s legal limit of 80 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 14 ppb, in 2019.

What handles it

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

Nitrate

Comes from the source

Below EPA’s limits

0.68ppm

Highest sample; found in 4 of 7

2025: not found

The highest sample, in 2020, was 0.68 ppm, below EPA’s legal limit of 10 ppm. 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 sample of 1.9 ppm, in 2014.

What handles it

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

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.23ppm

Highest yearly average, 2020 to 2023

2023: not found

Averaged by year, the highest was 0.23 ppm, in 2020, below EPA’s legal limit of 4.0 ppm. In 2023, 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 0.29 ppm, in 2014.

What handles it

Chromium (total)

Comes from the source

Below EPA’s limits

1.2ppb

Highest yearly average, 2020 to 2023

Averaged by year, the highest was 1.2 ppb, in 2023, below EPA’s legal limit of 100 ppb. That was also the latest year on file.

What handles it

3 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Arsenic
  • Haloacetic acids (HAA5)
  • 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.”

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

Hardness

Very hard, 275 mg/L (16.1 grains per gallon), at its one sampling point, 2020 to 2023.

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 16.1 grains per gallon, salt includedSoftener or salt-free conditioner?California water hardness, utility by utility

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
Lead and Copper Rule RevisionsThe required inventory of lead service lines was not completed or submitted on time.EPA: LSL InventoryMay 1, 2025—Unaddressed
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), nitrate, fluoride, chromium (total), arsenic and haloacetic acids (HAA5) results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. South Cloverdale Water Company’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 Feb. 26, 2020 to Sept. 25, 2025.

Testing your own tap

South Cloverdale Water Company’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.

No lab California certifies is within 75 miles of the area South Cloverdale Water Company serves on the state’s list. Some take samples by mail; the state’s page lists them all.

All 145 certified labs for California

Sources

PWSID CA4900510. Rebuilt from EPA data on Oct. 18, 2026.

Also in Sonoma County

All California utilities

What to do next