Skip to content
TapBuff
ZIP

Collinsville Water Works

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
25 people
Connections
15
Water source
Groundwater
Based in
Birds Landing, CA
County
Solano
Owner
Private
Hardness
Soft
The ZIP code it serves

94585

The short answer

1 result is above the limit’s level with no violation recorded. The worst: Arsenic, above the limit’s level, no violation. 1 health-based violation since 2016.

What handles it

What was found

Arsenic and nitrate: California’s own results, samples taken from Jan. 3, 2023 to Jan. 3, 2023, with EPA’s 2012 to 2019 file for earlier years.

Fluoride and chromium (total): EPA’s compliance monitoring file, samples taken from May 12, 2015 to Feb. 11, 2019. Newer results are in the utility’s annual water quality report.

Above the limit’s level, no violation recorded1

Arsenic

Comes from the source

Above the limit’s level, no violation

17ppb

Highest yearly average, 2023

Averaged by year, the highest was 17 ppb, in 2023, above EPA’s legal limit of 10 ppb. That is the only year on file. EPA judges this limit on running averages at each sampling point, and recorded no violation for arsenic at this utility since 2020. Results like these with no violation often include water sampled before treatment or blending; the utility’s annual report says what reaches the tap. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 21 ppb, in 2017.

What handles it

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

Below EPA’s limits2

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.28ppm

Highest yearly average, 2015 to 2019

2019, one sample: 0.22 ppm

Averaged by year, the highest was 0.28 ppm, in 2015, below EPA’s legal limit of 4.0 ppm. In 2019, the latest year on file, its one sample was 0.22 ppm.

What handles it

Chromium (total)

Comes from the source

Below EPA’s limits

3.0ppb

Highest yearly average, 2015 to 2019

Averaged by year, the highest was 3.0 ppb, in 2019, below EPA’s legal limit of 100 ppb. That was also the latest year on file.

What handles it

2 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Lead
  • Nitrate

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

    Claim: Arsenic (Pentavalent)<=50 ppb Reduction

    For: Arsenic

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

  • NSF/ANSI 58

    Claim: Arsenic (Pentavalent)<=50 ppb Reduction

    For: Arsenic

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

At the tap, or for the whole house?

These come with the water itself, so a whole-house system certified for the same claims treats every tap and shower. A filter at the tap treats drinking water for much less. 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

Hardness

Soft, 19 mg/L (1.1 grains per gallon), at its one sampling point, in 2019.

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 1.1 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 InventoryOct. 17, 2024—Unaddressed
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 1 monitoring or reporting violation not shown.

What this report can’t tell you

  • Everything else. Arsenic and nitrate results here are California’s own from 2023 on, with EPA’s national file for 2012 to 2019. Fluoride and chromium (total) come from EPA’s file alone, which ends in 2019. Collinsville Water Works’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 Jan. 3, 2023 to Jan. 3, 2023; EPA’s compliance samples are from May 12, 2015 to Feb. 11, 2019.

Testing your own tap

Collinsville Water Works’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 3 labs California certifies closest to the area Collinsville Water Works serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Napa-Solano-Yolo-Marin Public Health Laboratory

    Fairfield, CA · about 8 miles

    Certified for bacteria

    (707) 784-4410

  • McCampbell Analytical, Inc.

    Pittsburg, CA · about 11 miles

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

    (925) 252-9262

  • Caltest Analytical Laboratory

    Napa, CA · about 18 miles

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

    (707) 258-4000

All 145 certified labs for California

Sources

PWSID CA4800511. Rebuilt from EPA data on Oct. 18, 2026.

Also in Solano County

All California utilities

What to do next