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Vista Hills Mutual 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
75 people
Connections
22
Water source
Groundwater
Based in
Lompoc, CA
County
Santa Barbara
Owner
Private
Hardness
Very hard
The ZIP code it serves

93436

The short answer

1 result is above the health goal. The worst: Arsenic, above the health goal. 1 health-based violation since 2016.

What handles it

What was found

Arsenic, nitrate, total trihalomethanes (TTHM), haloacetic acids (HAA5), fluoride, chromium (total) and uranium: California’s own results, samples taken from Dec. 23, 2020 to Sept. 30, 2025, with EPA’s 2012 to 2019 file for earlier years.

Above the health goal1

Arsenic

Comes from the source

Above the health goal

4.3ppb

Highest yearly average, 2021 to 2025

2025, one sample: 3.9 ppb

Averaged by year, the highest was 4.3 ppb, in 2021: below EPA’s legal limit of 10 ppb, but above its health goal of zero. Its highest single sample was 4.4 ppb. In 2025, the latest year on file, its one sample was 3.9 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 7.4 ppb, in 2019.

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 limits4

Nitrate

Comes from the source

Below EPA’s limits

1.8ppm

Highest sample; found in 6 of 13

2025 average: 0.8 ppm

The highest sample, in 2020, was 1.8 ppm, below EPA’s legal limit of 10 ppm. In 2025, the latest year on file, its two samples averaged 0.8 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 2.0 ppm, in 2016.

What handles it

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

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

14.3ppb

Highest yearly average, 2021 to 2025

Averaged by year, the highest was 14.3 ppb, in 2025, below EPA’s legal limit of 80 ppb. Its highest single sample was 21.1 ppb. That was also the latest year on file.

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

6.2ppb

Highest yearly average, 2023 to 2025

Averaged by year, the highest was 6.2 ppb, in 2025, below EPA’s legal limit of 60 ppb. That was also the latest year on file.

What handles it

No certification claim covers this compound yet.

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.27ppm

Highest yearly average, 2021 to 2025

2025, one sample: 0.22 ppm

Averaged by year, the highest was 0.27 ppm, in 2021, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 0.31 ppm. In 2025, the latest year on file, its one sample was 0.22 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.38 ppm, in 2012.

What handles it

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

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

Very hard, typically 380 mg/L (22.2 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 at 22.2 grains per gallon, salt includedSoftener or salt-free conditioner?California water hardness, utility by utility

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
SeleniumThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2025 to March 31, 202567.5 UG/LResolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 4 monitoring or reporting violations not shown.

What this report can’t tell you

  • Everything else. Arsenic, nitrate, total trihalomethanes (TTHM), haloacetic acids (HAA5), fluoride, chromium (total) and uranium results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. Vista Hills Mutual 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 Dec. 23, 2020 to Sept. 30, 2025.

Testing your own tap

Vista Hills Mutual 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.

The 3 labs California certifies closest to the area Vista Hills Mutual Water Company serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Clinical Laboratory of San Bernardino II

    Lompoc, CA · about 5 miles

    Certified for bacteria

    (805) 737-7300

  • Oilfield Environmental & Compliance Inc. (OEC)

    Santa Maria, CA · about 26 miles

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

    (805) 922-4772

  • Abalone Coast Analytical, Inc.

    San Luis Obispo, CA · about 48 miles

    Certified for bacteria

    (805) 595-1080

All 145 certified labs for California

Sources

PWSID CA4200848. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Santa Barbara County

All California utilities

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