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Phoenix Lake Estates Cc MWC

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
1,168 people
Connections
358
Water source
Groundwater
Based in
Standard, CA
County
Tuolumne
Owner
Private
Hardness
Varies by source
The ZIP code it serves

95370

The short answer

1 result is above the health goal. The worst: Uranium, above the health goal. No health-based violations on file since 2016.

What handles it

What was found

Uranium, nitrate, total trihalomethanes (TTHM), fluoride, arsenic, chromium (total) and haloacetic acids (HAA5): California’s own results, samples taken from Aug. 10, 2020 to Jan. 20, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the health goal1

Uranium

Comes from the source

Above the health goal

12.1ppb

Highest yearly average, 2022 to 2025

2025 average: 9.4 ppb

Averaged by year, the highest was 12.1 ppb, in 2022: below EPA’s legal limit of 30 ppb, but above its health goal of zero. Its highest single sample was 21.5 ppb. In 2025, the latest year on file, its seven samples averaged 9.4 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 12.2 ppb, in 2018.

What handles it

Below EPA’s limits3

Nitrate

Comes from the source

Below EPA’s limits

2.4ppm

Highest sample; found in 20 of 40

2026 average: 0.21 ppm

The highest sample, in 2021, was 2.4 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, its five samples averaged 0.21 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 4.2 ppm, in 2012.

What handles it

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

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

3.6ppb

Highest yearly average, 2025

Averaged by year, the highest was 3.6 ppb, in 2025, below EPA’s legal limit of 80 ppb. Its highest single sample was 7.3 ppb. That is the only year on file.

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

0.11ppm

Highest yearly average, 2021 to 2025

2025: not found

Averaged by year, the highest was 0.11 ppm, in 2024, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 0.31 ppm. In 2025, the latest year on file, it wasn’t found in its one sample.

What handles it

4 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Arsenic
  • Chromium (total)
  • 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.”

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

None of the filters TapBuff has checked so far carry these claims. Search the certifier listings for the claim above.

Compare five-year costs

Hardness

Hard to very hard depending on the source, 130 to 257 mg/L (7.6 to 15 grains per gallon), across 6 sampling points, 2021 to 2025.

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. There is 1 monitoring or reporting violation: a sample missed, late or not reported.

What this report can’t tell you

  • Everything else. Uranium, nitrate, total trihalomethanes (TTHM), fluoride, arsenic, chromium (total) and haloacetic acids (HAA5) results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. Phoenix Lake Estates Cc MWC’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. 10, 2020 to Jan. 20, 2026.

Testing your own tap

Phoenix Lake Estates Cc MWC’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 Phoenix Lake Estates Cc MWC serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Precision Enviro-Tech

    Twain Harte, CA · about 8 miles

    Certified for bacteria

    (209) 477-8105

  • 49er Water Laboratory

    Jackson, CA · about 34 miles

    Certified for bacteria, nitrate, minerals and other inorganics

    (530) 277-2770

  • Aemtek, Inc.

    Modesto, CA · about 41 miles

    Certified for bacteria

    (510) 979-1979

All 145 certified labs for California

Sources

PWSID CA5510026. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Tuolumne County

All California utilities

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