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Del Oro Water Company - Strawberry Div.

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
386 people
Connections
393
Water source
Surface water
Based in
Chico, CA
County
Tuolumne
Owner
Private
Hardness
Soft
The ZIP code it serves

95375

The short answer

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

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 2006 to 2025.

Arsenic, haloacetic acids (HAA5), total trihalomethanes (TTHM), chromium (total), fluoride and nitrate: California’s own results, samples taken from Feb. 12, 2020 to April 8, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the health goal2

Arsenic

Comes from the source

Above the health goal

2.2ppb

Highest yearly average, 2020 to 2026

2026: not found

Averaged by year, the highest was 2.2 ppb, in 2020: below EPA’s legal limit of 10 ppb, but above its health goal of zero. Its highest single sample was 4.3 ppb. In 2026, 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 0.38 ppb, in 2017.

What handles it

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

Lead

Comes from pipes, often your own

Above the health goal

0.9ppb

90th percentile, 2023 to 2025

In the latest period, 9 in 10 homes sampled were at or below 0.9 ppb, below EPA’s action level of 15 ppb. The action level drops to 10 ppb on Nov. 1, 2027. EPA’s health goal for lead is zero.

What handles it

Below EPA’s limits2

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

52ppb

Highest yearly average, 2020 to 2026

2026 average: 37.9 ppb

Averaged by year, the highest was 52 ppb, in 2022, below EPA’s legal limit of 60 ppb. Its highest single sample was 116 ppb. In 2026, the latest year on file, its two samples averaged 37.9 ppb. EPA recorded no violation for haloacetic acids (HAA5) at this utility since 2020. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 73.5 ppb, in 2018.

What handles it

No certification claim covers this compound yet.

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

68.1ppb

Highest yearly average, 2020 to 2026

2026 average: 66.5 ppb

Averaged by year, the highest was 68.1 ppb, in 2024, below EPA’s legal limit of 80 ppb. Its highest single sample was 99 ppb. In 2026, the latest year on file, its two samples averaged 66.5 ppb. EPA recorded no violation for total trihalomethanes (TTHM) at this utility since 2020. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 106 ppb, in 2018.

What handles it

  • NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
  • NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”
3 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Chromium (total)
  • Fluoride
  • Nitrate

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: Arsenic (Pentavalent)<=50 ppb Reduction, Lead Reduction

    For: Arsenic, Lead

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

  • NSF/ANSI 58

    Claims: Arsenic (Pentavalent)<=50 ppb Reduction, Lead Reduction

    For: Arsenic, Lead

    Other certifiers’ wording: Arsenic (Pentavalent)<=300 ppb Reduction; Arsenic (V) (300 ppb influent level)

At the tap, or for the whole house?

Lead and copper usually come from pipes and fixtures inside or near your home. A whole-house system sits where water enters, so it cannot catch what your own plumbing adds after it. For those, the filter that counts is the one at the tap. 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

The best water filters for lead, ranked

Hardness

Soft, typically 14 mg/L (0.8 grains per gallon), across 3 sampling points, 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 0.8 grains per gallon, salt includedSoftener or salt-free conditioner?California water hardness, utility by utility

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
Surface Water Treatment RuleRequired treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR)Feb. 1, 2025 to Feb. 28, 2025—Resolved
Surface Water Treatment RuleRequired treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR)Feb. 1, 2018 to Feb. 28, 2018—Resolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 1 monitoring or reporting violation not shown.

What this report can’t tell you

  • Everything else. Arsenic, haloacetic acids (HAA5), total trihalomethanes (TTHM), chromium (total), fluoride and nitrate results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. Del Oro Water Company - Strawberry Div.’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 Feb. 12, 2020 to April 8, 2026.

Testing your own tap

Del Oro Water Company - Strawberry Div.’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 Del Oro Water Company - Strawberry Div. 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 15 miles

    Certified for bacteria

    (209) 477-8105

  • 49er Water Laboratory

    Jackson, CA · about 42 miles

    Certified for bacteria, nitrate, minerals and other inorganics

    (530) 277-2770

  • Aemtek, Inc.

    Modesto, CA · about 63 miles

    Certified for bacteria

    (510) 979-1979

All 145 certified labs for California

Sources

PWSID CA5510007. Rebuilt from EPA data on Oct. 18, 2026.

Also in Tuolumne County

All California utilities

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