Skip to content
TapBuff
ZIP

San Andreas 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
392 people
Connections
140
Water source
Groundwater
Based in
La Selva Beach, CA
County
Santa Cruz
Owner
Private
Hardness
Varies by source
The ZIP code it serves

95076

The short answer

3 results are above the health goal. The worst: Nitrate, above the health goal. No health-based violations on file since 2016.

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 2019 to 2024.

Nitrate, arsenic, chromium (total), fluoride and uranium: California’s own results, samples taken from Jan. 2, 2020 to July 6, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the health goal3

Nitrate

Comes from the source

Above the health goal

29ppm

Highest sample; found in 205 of 205

2026 average: 7.7 ppm

From 2020 to 2023, 19 samples were above EPA’s legal limit of 10 ppm, the highest 29 ppm in 2022. The next sample at the same point, within 30 days, kept the average above the limit for five; 14 have no follow-up sample on file within 30 days. 10 ppm is also EPA’s health goal. In 2026, the latest year on file, its 21 samples averaged 7.7 ppm. EPA recorded no violation for nitrate at this utility since 2020. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 24.9 ppm, in 2014.

What handles it

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

Arsenic

Comes from the source

Above the health goal

1.8ppb

Highest yearly average, 2021 to 2026

2026: not found

Averaged by year, the highest was 1.8 ppb, in 2021: below EPA’s legal limit of 10 ppb, but above its health goal of zero. Its highest single sample was 2.3 ppb. In 2026, the latest year on file, it wasn’t found in any of its two samples. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.6 ppb, in 2015.

What handles it

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

Lead

Comes from pipes, often your own

Above the health goal

1.8ppb

90th percentile, 2022 to 2024

In the latest period, 9 in 10 homes sampled were at or below 1.8 ppb, below EPA’s action level of 15 ppb. The action level drops to 10 ppb on Nov. 1, 2027. EPA’s health goal for lead is zero.

What handles it

Below EPA’s limits2

Chromium (total)

Comes from the source

Below EPA’s limits

18.4ppb

Highest yearly average, 2021 to 2026

2026 average: 17.4 ppb

Averaged by year, the highest was 18.4 ppb, in 2025, below EPA’s legal limit of 100 ppb. Its highest single sample was 21.6 ppb. In 2026, the latest year on file, its two samples averaged 17.4 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 16.7 ppb, in 2017.

What handles it

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.15ppm

Highest yearly average, 2021 to 2026

2026 average: 0.1 ppm

Averaged by year, the highest was 0.15 ppm, in 2024, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 0.2 ppm. In 2026, the latest year on file, its two samples averaged 0.1 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.18 ppm, in 2015.

What handles it

One compound tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • 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

    Claims: Nitrate/Nitrite (30 ppm challenge), Arsenic (Pentavalent)<=50 ppb Reduction, Lead Reduction

    For: Nitrate, Arsenic, Lead

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

  • NSF/ANSI 58

    Claims: Nitrate/Nitrite Reduction, Arsenic (Pentavalent)<=50 ppb Reduction, Lead Reduction

    For: Nitrate, Arsenic, Lead

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

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

The best reverse osmosis systems, ranked

The best water filters for lead, ranked

Hardness

Moderately hard to very hard depending on the source, 120 to 190 mg/L (7 to 11.1 grains per gallon), across 3 sampling points, 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, salt includedSoftener or salt-free conditioner?California water hardness, utility by utility

Violations since 2016

No health-based violations on file with EPA since 2016.

What this report can’t tell you

  • Everything else. Nitrate, arsenic, chromium (total), fluoride and uranium results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. San Andreas 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. 2, 2020 to July 6, 2026.

Testing your own tap

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

  • CM Analytical, Inc.

    Gilroy, CA · about 12 miles

    Certified for bacteria

    (408) 848-3619

  • Bracewell Engineering, Inc.

    Morgan Hill, CA · about 14 miles

    Certified for bacteria, nitrate, minerals and other inorganics

    (669) 258-5821

  • Santa Cruz County - Health Services Agency - Environmental Health

    Santa Cruz, CA · about 15 miles

    Certified for bacteria

    (831) 454-4624

All 145 certified labs for California

Sources

PWSID CA4400558. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Santa Cruz County

All California utilities

What to do next