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Valenzuela Water System

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
55 people
Connections
17
Water source
Groundwater
Based in
Hollister, CA
County
San Benito
Owner
Private
Hardness
Very hard
The ZIP code it serves

95023

The short answer

3 results are above the health goal. The worst: Nitrate, above the health goal. 2 health-based violations since 2016.

What handles it

What was found

Nitrate, arsenic, uranium, chromium (total), haloacetic acids (HAA5), total trihalomethanes (TTHM) and fluoride: California’s own results, samples taken from Jan. 2, 2020 to June 29, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the health goal3

Nitrate

Comes from the source

Above the health goal

34.5ppm

Highest sample; found in 417 of 418

2026 average: 12.7 ppm

From 2020 to 2025, at least 25 samples were above EPA’s legal limit of 10 ppm, the highest 34.5 ppm in 2020. The next sample at the same point, within 30 days, kept the average above the limit for 24; 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, its 33 samples averaged 12.7 ppm, above the limit. EPA recorded no violation for nitrate at this utility since 2020. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 17.8 ppm, in 2018, and EPA recorded a violation in 2018.

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

3.5ppb

Highest yearly average, 2020 to 2026

2026: not found

Averaged by year, the highest was 3.5 ppb, in 2020: below EPA’s legal limit of 10 ppb, but above its health goal of zero. In 2026, the latest year on file, it wasn’t found in its one sample.

What handles it

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

Uranium

Comes from the source

Above the health goal

4.6ppb

Highest yearly average, 2024

Averaged by year, the highest was 4.6 ppb, in 2024: below EPA’s legal limit of 30 ppb, but above its health goal of zero. That is the only year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 4.5 ppb, in 2012.

What handles it

Below EPA’s limits4

Chromium (total)

Comes from the source

Below EPA’s limits

42.2ppb

Highest yearly average, 2020 to 2026

Averaged by year, the highest was 42.2 ppb, in 2026, below EPA’s legal limit of 100 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 22 ppb, in 2014.

What handles it

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

12ppb

Highest yearly average, 2020 to 2025

2025: not found

Averaged by year, the highest was 12 ppb, in 2020, below EPA’s legal limit of 60 ppb. In 2025, the latest year on file, it wasn’t found in its one sample. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 6.4 ppb, in 2017.

What handles it

No certification claim covers this compound yet.

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

14.8ppb

Highest yearly average, 2020 to 2025

2025, one sample: 8.0 ppb

Averaged by year, the highest was 14.8 ppb, in 2020, below EPA’s legal limit of 80 ppb. In 2025, the latest year on file, its one sample was 8.0 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 18.9 ppb, in 2018.

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

0.3ppm

Highest yearly average, 2020 to 2026

2026, one sample: 0.3 ppm

Averaged by year, the highest was 0.3 ppm, in 2020, below EPA’s legal limit of 4.0 ppm. In 2026, the latest year on file, its one sample was 0.3 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.36 ppm, in 2017.

What handles it

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

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

    For: Nitrate, Arsenic

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

  • NSF/ANSI 58

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

    For: Nitrate, Arsenic, Uranium

    Other certifiers’ wording: Nitrate; 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, 593 mg/L (34.7 grains per gallon), at its one sampling point, 2020 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 34.7 grains per gallon, salt includedSoftener or salt-free conditioner?California water hardness, utility by utility

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
Nitrate-NitriteA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleMay 1, 2018 to May 31, 201818 MG/LArchived
Nitrate-NitriteA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleApril 1, 2018 to April 30, 201811 MG/LArchived
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, arsenic, uranium, chromium (total), haloacetic acids (HAA5), total trihalomethanes (TTHM) and fluoride results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. Valenzuela Water System’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 June 29, 2026.

Testing your own tap

Valenzuela Water System’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 Valenzuela Water System 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 13 miles

    Certified for bacteria

    (408) 848-3619

  • Monterey County Consolidated Environmental Laboratory

    Salinas, CA · about 21 miles

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

    (831) 755-4516

  • Bracewell Engineering, Inc.

    Morgan Hill, CA · about 22 miles

    Certified for bacteria, nitrate, minerals and other inorganics

    (669) 258-5821

All 145 certified labs for California

Sources

PWSID CA3500527. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in San Benito County

All California utilities

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