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Bluebell Valley 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
252 people
Connections
94
Water source
Groundwater
Based in
Standard, CA
County
Tuolumne
Owner
Private
Hardness
Hard
The ZIP code it serves

95370

The short answer

1 result is above the limit’s level with no violation recorded, and 2 more are above the health goal. The worst: Uranium, above the limit’s level, no violation. 1 health-based violation since 2016.

What handles it

What was found

Uranium, nitrate, arsenic, chromium (total), fluoride and total trihalomethanes (TTHM): California’s own results, samples taken from March 27, 2020 to April 22, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the limit’s level, no violation recorded1

Uranium

Comes from the source

Above the limit’s level, no violation

31.3ppb

Highest yearly average, 2022 to 2026

2026, one sample: 6.0 ppb

Averaged by year, the highest was 31.3 ppb, in 2025, above EPA’s legal limit of 30 ppb. In 2026, the latest year on file, its one sample was 6.0 ppb. EPA judges this limit on running averages at each sampling point, and recorded no violation for uranium at this utility since 2020. Results like these with no violation often include water sampled before treatment or blending; the utility’s annual report says what reaches the tap. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 14.8 ppb, in 2012.

What handles it

Above the health goal2

Nitrate

Comes from the source

Above the health goal

10.5ppm

Highest sample; found in 52 of 52

2026 average: 3.9 ppm

One sample, in 2020, was above EPA’s legal limit of 10 ppm, at 10.5 ppm. The next sample at the same point, within 30 days, brought the average back under the limit. 10 ppm is also EPA’s health goal. In 2026, the latest year on file, its four samples averaged 3.9 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 11 ppm, in 2015.

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

1.6ppb

Highest yearly average, 2022 to 2025

2025: not found

Averaged by year, the highest was 1.6 ppb, in 2022: below EPA’s legal limit of 10 ppb, but above its health goal of zero. Its highest single sample was 2.6 ppb. In 2025, the latest year on file, it wasn’t found in any of its two samples. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 8.7 ppb, in 2015.

What handles it

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

Below EPA’s limits2

Chromium (total)

Comes from the source

Below EPA’s limits

8.8ppb

Highest yearly average, 2022 to 2025

2025: not found

Averaged by year, the highest was 8.8 ppb, in 2022, below EPA’s legal limit of 100 ppb. Its highest single sample was 14.5 ppb. In 2025, the latest year on file, it wasn’t found in any of its two samples. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 11.4 ppb, in 2018.

What handles it

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.27ppm

Highest yearly average, 2022 to 2025

2025 average: 0.17 ppm

Averaged by year, the highest was 0.27 ppm, in 2022, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 0.33 ppm. In 2025, the latest year on file, its two samples averaged 0.17 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.29 ppm, in 2016.

What handles it

2 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Lead
  • Total trihalomethanes (TTHM)

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

    For: Uranium, Nitrate, Arsenic

    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

Hard, typically 141 mg/L (8.2 grains per gallon), across 3 sampling points, 2019 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 at 8.2 grains per gallon, salt includedSoftener or salt-free conditioner?California water hardness, utility by utility

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
Coliform (TCR)Maximum Contaminant Level Violation, Acute (TCR)March 1, 2016 to March 31, 2016—Resolved
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. Uranium, nitrate, arsenic, chromium (total), fluoride and total trihalomethanes (TTHM) results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. Bluebell Valley 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 March 27, 2020 to April 22, 2026.

Testing your own tap

Bluebell Valley 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 Bluebell Valley 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 CA5500040. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Tuolumne County

All California utilities

What to do next