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Moro Cojo Mwa

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
67 people
Connections
19
Water source
Groundwater
Based in
Prunedale, CA
County
Monterey
Owner
Private
Hardness
Varies by source
The ZIP code it serves

93907

The short answer

2 results are above the health goal. The worst: Nitrate, above the health goal. 1 health-based violation since 2016.

What handles it

What was found

Nitrate, uranium, chromium (total), total trihalomethanes (TTHM), fluoride, arsenic and haloacetic acids (HAA5): California’s own results, samples taken from Jan. 21, 2020 to June 15, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the health goal2

Nitrate

Comes from the source

Above the health goal

24.5ppm

Highest sample; found in 138 of 151

2026 average: 7.1 ppm

From 2020 to 2026, at least 25 samples were above EPA’s legal limit of 10 ppm, the highest 24.5 ppm in 2023. One came back under the limit on the next sample at the same point and 24 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 12 samples averaged 7.1 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 13.8 ppm, in 2015.

What handles it

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

Uranium

Comes from the source

Above the health goal

7.9ppb

Highest yearly average, 2022 to 2023

Averaged by year, the highest was 7.9 ppb, in 2023: below EPA’s legal limit of 30 ppb, but above its health goal of zero. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 7.0 ppb, in 2019.

What handles it

Below EPA’s limits3

Chromium (total)

Comes from the source

Below EPA’s limits

8.7ppb

Highest yearly average, 2023

Averaged by year, the highest was 8.7 ppb, in 2023, below EPA’s legal limit of 100 ppb. Its highest single sample was 26 ppb. That is the only year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.5 ppb, in 2019.

What handles it

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

4.1ppb

Highest yearly average, 2020 to 2023

2023, one sample: 4.1 ppb

Averaged by year, the highest was 4.1 ppb, in 2020, below EPA’s legal limit of 80 ppb. In 2023, the latest year on file, its one sample was 4.1 ppb.

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

0.14ppm

Highest yearly average, 2023

Averaged by year, the highest was 0.14 ppm, in 2023, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 0.37 ppm. That is the only year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.28 ppm, in 2016.

What handles it

3 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Arsenic
  • Haloacetic acids (HAA5)
  • 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

    Claims: Nitrate/Nitrite Reduction, Uranium

    For: Nitrate, Uranium

    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 to very hard depending on the source, 91 to 181 mg/L (5.3 to 10.6 grains per gallon), across 3 sampling points, 2019 to 2023.

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

Contaminant or ruleTypePeriodMeasuredStatus
Lead and Copper Rule RevisionsThe required inventory of lead service lines was not completed or submitted on time.EPA: LSL InventoryOct. 17, 2024—Addressed
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 2 monitoring or reporting violations not shown.

What this report can’t tell you

  • Everything else. Nitrate, uranium, chromium (total), total trihalomethanes (TTHM), fluoride, arsenic and haloacetic acids (HAA5) results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. Moro Cojo Mwa’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. 21, 2020 to June 15, 2026.

Testing your own tap

Moro Cojo Mwa’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 Moro Cojo Mwa serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Monterey County Consolidated Environmental Laboratory

    Salinas, CA · about 5 miles

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

    (831) 755-4516

  • Monterey Bay Analytical Services, Inc.

    Monterey, CA · about 15 miles

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

    (831) 375-6227

  • CM Analytical, Inc.

    Gilroy, CA · about 17 miles

    Certified for bacteria

    (408) 848-3619

All 145 certified labs for California

Sources

PWSID CA2700656. Rebuilt from EPA data on Oct. 18, 2026.

Also in Monterey County

All California utilities

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