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Senior Canyon Mutual Water Co

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
800 people
Connections
250
Water source
Surface water
Based in
Ojai, CA
County
Ventura
Owner
Private
Hardness
Very hard
The ZIP code it serves

93023

The short answer

1 result is above the health goal. The worst: Nitrate, above the health goal. 2 health-based violations since 2016.

What handles it

What was found

Copper: EPA’s file records a utility’s copper only when it exceeds the action level. The last here was 1.4 ppm, for the period ending Dec. 31, 1994. None since is on file, so it is not counted as a current finding.

Nitrate, haloacetic acids (HAA5), total trihalomethanes (TTHM), fluoride, arsenic and chromium (total): California’s own results, samples taken from Jan. 6, 2020 to March 5, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the health goal1

Nitrate

Comes from the source

Above the health goal

14.7ppm

Highest sample; found in 6 of 10

2026: not found

In 2020, four samples were above EPA’s legal limit of 10 ppm, the highest 14.7 ppm. The next sample at the same point, within 30 days, kept the average above the limit for three; one has no follow-up sample on file within 30 days. 10 ppm is also EPA’s health goal. In 2026, the latest year on file, it wasn’t found in its one sample. EPA recorded no violation for nitrate at this utility since 2020. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 14 ppm, in 2019.

What handles it

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

Below EPA’s limits3

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

44ppb

Highest yearly average, 2020 to 2025

2025 average: 37 ppb

Averaged by year, the highest was 44 ppb, in 2022, below EPA’s legal limit of 60 ppb. Its highest single sample was 51 ppb. In 2025, the latest year on file, its two samples averaged 37 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 40 ppb, in 2015.

What handles it

No certification claim covers this compound yet.

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

38.5ppb

Highest yearly average, 2020 to 2025

2025 average: 26.7 ppb

Averaged by year, the highest was 38.5 ppb, in 2021, below EPA’s legal limit of 80 ppb. Its highest single sample was 50 ppb. In 2025, the latest year on file, its three samples averaged 26.7 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 62.1 ppb, in 2015.

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

0.4ppm

Highest yearly average, 2020 to 2026

2026, one sample: 0.2 ppm

Averaged by year, the highest was 0.4 ppm, in 2021, below EPA’s legal limit of 4.0 ppm. In 2026, the latest year on file, its one sample was 0.2 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.3 ppm, in 2014.

What handles it

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

  • NSF/ANSI 53

    Claim: Nitrate/Nitrite (30 ppm challenge)

    For: Nitrate

  • NSF/ANSI 58

    Claim: Nitrate/Nitrite Reduction

    For: Nitrate

    Other certifiers’ wording: Nitrate

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

Very hard, typically 409 mg/L (23.9 grains per gallon), across 2 sampling points, 2019 to 2026.

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

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
Surface Water Treatment RuleRequired treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR)May 1, 2017 to May 31, 2017—Resolved
Revised Total Coliform RuleE. coli was confirmed in the water system.EPA: Maximum Contaminant Level Violation, E. coli (RTCR)Oct. 1, 2016 to Oct. 31, 2016—Resolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 3 monitoring or reporting violations not shown.

What this report can’t tell you

  • Everything else. Nitrate, haloacetic acids (HAA5), total trihalomethanes (TTHM), fluoride, arsenic and chromium (total) results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. Senior Canyon Mutual Water Co’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 Jan. 6, 2020 to March 5, 2026.

Testing your own tap

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

  • Fruit Growers Laboratory, Inc.

    Santa Paula, CA · about 19 miles

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

    (805) 392-2000

  • Capco Analytical Services

    Ventura, CA · about 19 miles

    Certified for bacteria, nitrate, metals, minerals and other inorganics

    (805) 644-1095

  • Ventura County Public Health Laboratory

    Oxnard, CA · about 23 miles

    Certified for bacteria

    (805) 981-5131

All 145 certified labs for California

Sources

PWSID CA5601117. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Ventura County

All California utilities

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