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Zonneveld Dairy - Cerini

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
36 people
Connections
14
Water source
Groundwater
Based in
Laton, CA
County
Fresno
Owner
Private
Hardness
Soft
The ZIP code it serves

93242

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

Nitrate, arsenic, uranium, fluoride, total trihalomethanes (TTHM), haloacetic acids (HAA5) and chromium (total): California’s own results, samples taken from Jan. 9, 2020 to April 8, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the health goal3

Nitrate

Comes from the source

Above the health goal

15ppm

Highest sample; found in 107 of 113

2026 average: 4.4 ppm

From 2020 to 2022, six samples were above EPA’s legal limit of 10 ppm, the highest 15 ppm in 2022. Six 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 seven samples averaged 4.4 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 21 ppm, in 2016.

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

8.4ppb

Highest yearly average, 2020 to 2026

Averaged by year, the highest was 8.4 ppb, in 2026: below EPA’s legal limit of 10 ppb, but above its health goal of zero. Its highest single sample was 30 ppb. That was also the latest year on file. EPA recorded no violation for arsenic at this utility since 2020. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 22 ppb, in 2012.

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

24.5ppb

Highest yearly average, 2020 to 2026

2026 average: 13.6 ppb

Averaged by year, the highest was 24.5 ppb, in 2023: below EPA’s legal limit of 30 ppb, but above its health goal of zero. Its highest single sample was 40.2 ppb. In 2026, the latest year on file, its two samples averaged 13.6 ppb. EPA recorded no violation for uranium at this utility since 2020. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 60.3 ppb, in 2016.

What handles it

Below EPA’s limits3

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.35ppm

Highest yearly average, 2022 to 2025

2025, one sample: 0.34 ppm

Averaged by year, the highest was 0.35 ppm, in 2022, below EPA’s legal limit of 4.0 ppm. In 2025, the latest year on file, its one sample was 0.34 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.4 ppm, in 2013.

What handles it

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

5.4ppb

Highest yearly average, 2021 to 2024

2024: not found

Averaged by year, the highest was 5.4 ppb, in 2021, below EPA’s legal limit of 80 ppb. In 2024, 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 2016.

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

2.1ppb

Highest yearly average, 2021 to 2024

2024: not found

Averaged by year, the highest was 2.1 ppb, in 2021, below EPA’s legal limit of 60 ppb. In 2024, 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 2.9 ppb, in 2016.

What handles it

No certification claim covers this compound yet.

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

    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

Soft, 15 mg/L (0.9 grains per gallon), at its one sampling point, 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 0.9 grains per gallon, 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. There is 1 monitoring or reporting violation: a sample missed, late or not reported.

What this report can’t tell you

  • Everything else. Nitrate, arsenic, uranium, fluoride, total trihalomethanes (TTHM), haloacetic acids (HAA5) and chromium (total) results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. Zonneveld Dairy - Cerini’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. 9, 2020 to April 8, 2026.

Testing your own tap

Zonneveld Dairy - Cerini’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 Zonneveld Dairy - Cerini serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Fruit Growers Laboratory, Inc.

    Visalia, CA · about 20 miles

    Certified for bacteria

    (559) 734-9473

  • Moore Twining Associates, Inc.

    Fresno, CA · about 21 miles

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

    (559) 268-7021

  • BSK Associates

    Fresno, CA · about 21 miles

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

    (559) 497-2888

All 145 certified labs for California

Sources

PWSID CA1000627. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Fresno County

All California utilities

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