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Aptos Hills 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
32 people
Connections
11
Water source
Groundwater
Based in
Watsonville, CA
County
Santa Cruz
Owner
Private
Hardness
Moderately hard
The ZIP code it serves

95076

The short answer

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

What handles it

What was found

Nitrate, chromium (total), fluoride and arsenic: California’s own results, samples taken from Aug. 8, 2023 to June 24, 2026.

Above the legal limit1

Nitrate

Comes from the source

Above the legal limit

10.9ppm

Highest sample; found in 34 of 34

2026 average: 6.0 ppm

One sample, in 2024, was above EPA’s legal limit of 10 ppm, at 10.9 ppm. No follow-up sample at that point within 30 days is on file. In 2026, the latest year on file, its six samples averaged 6.0 ppm. EPA recorded a violation for nitrate at this utility in 2024.

What handles it

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

Below EPA’s limits2

Chromium (total)

Comes from the source

Below EPA’s limits

42.3ppb

Highest yearly average, 2023 to 2026

2026, one sample: 32.3 ppb

Averaged by year, the highest was 42.3 ppb, in 2024, below EPA’s legal limit of 100 ppb. Its highest single sample was 117 ppb. In 2026, the latest year on file, its one sample was 32.3 ppb. EPA recorded no violation for chromium (total) at this utility since 2020.

What handles it

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.1ppm

Highest yearly average, 2023 to 2024

Averaged by year, the highest was 0.1 ppm, in 2024, below EPA’s legal limit of 4.0 ppm. 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.
  • Arsenic
  • 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

Moderately hard, typically 93 mg/L (5.4 grains per gallon), across 2 sampling points, 2023 to 2024.

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

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
NitrateThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageMarch 20, 2024 to June 19, 202410.1 MG/LArchived
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record.

What this report can’t tell you

  • Everything else. Nitrate, chromium (total), fluoride and arsenic results here are California’s own from 2023 on, with EPA’s national file for 2012 to 2019. Aptos Hills 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 Aug. 8, 2023 to June 24, 2026.

Testing your own tap

Aptos Hills 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 Aptos Hills 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 CA4400634. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Santa Cruz County

All California utilities

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