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Barton Flats Water System

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
11 people
Connections
16
Water source
Surface water
Based in
Angelus Oaks, CA
County
San Bernardino
Owner
Private
Hardness
Soft
The ZIP code it serves

92305

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: Haloacetic acids (HAA5), above the limit’s level, no violation. 5 health-based violations since 2016.

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 2019 to 2025.

Haloacetic acids (HAA5), total trihalomethanes (TTHM), fluoride, arsenic, chromium (total) and nitrate: California’s own results, samples taken from July 13, 2020 to March 16, 2026, with EPA’s 2012 to 2019 file for earlier years.

Uranium: EPA’s compliance monitoring file, samples taken from April 16, 2019 to April 16, 2019. Newer results are in the utility’s annual water quality report.

Above the limit’s level, no violation recorded1

Haloacetic acids (HAA5)

Forms or is added in treatment

Above the limit’s level, no violation

81.4ppb

Highest yearly average, 2023 to 2026

2026, one sample: 12.7 ppb

Averaged by year, the highest was 81.4 ppb, in 2023, above EPA’s legal limit of 60 ppb. In 2026, the latest year on file, its one sample was 12.7 ppb. EPA judges this limit on running averages at each sampling point, and recorded no violation for haloacetic acids (HAA5) 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 55 ppb, in 2019.

What handles it

No certification claim covers this compound yet.

Above the health goal2

Lead

Comes from pipes, often your own

Above the health goal

2.8ppb

90th percentile, 2023 to 2025

In the latest period, 9 in 10 homes sampled were at or below 2.8 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

Uranium

Comes from the source

Above the health goal

4.3ppb

Highest yearly average, 2019

Averaged by year, the highest was 4.3 ppb, in 2019: below EPA’s legal limit of 30 ppb, but above its health goal of zero. That is the only year on file.

What handles it

Below EPA’s limits2

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

31.9ppb

Highest yearly average, 2023 to 2026

2026: not found

Averaged by year, the highest was 31.9 ppb, in 2023, below EPA’s legal limit of 80 ppb. Its highest single sample was 63.7 ppb. In 2026, 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 70.2 ppb, in 2019.

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, 2021 to 2026

Averaged by year, the highest was 0.14 ppm, in 2026, below EPA’s legal limit of 4.0 ppm. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.15 ppm, in 2019.

What handles it

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

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 water filters for lead, ranked

Hardness

Soft, typically 28 mg/L (1.6 grains per gallon), across 2 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 1.6 grains per gallon, 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—Unaddressed
Interim Enhanced Surface Water Treatment RuleToo many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR)July 1, 2017 to July 31, 2017—Resolved
Interim Enhanced Surface Water Treatment RuleToo many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR)June 1, 2017 to June 30, 2017—Resolved
Interim Enhanced Surface Water Treatment RuleToo many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR)May 1, 2017 to May 31, 2017—Resolved
Interim Enhanced Surface Water Treatment RuleToo many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR)March 1, 2017 to March 31, 2017—Resolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 8 monitoring or reporting violations not shown.

What this report can’t tell you

  • Everything else. Haloacetic acids (HAA5), total trihalomethanes (TTHM), fluoride, arsenic, chromium (total) and nitrate results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. Uranium comes from EPA’s file alone, which ends in 2019. Barton Flats Water System’s own annual report, which it must send you every year, has newer results for those and 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 July 13, 2020 to March 16, 2026; EPA’s compliance samples are from April 16, 2019 to April 16, 2019.

Testing your own tap

Barton Flats Water System’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 Barton Flats Water System serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • BSK Associates - San Bernardino Analytical Laboratory

    San Bernardino, CA · about 27 miles

    Certified for bacteria

    (559) 497-2888

  • Clinical Laboratory of San Bernardino, Inc.

    Grand Terrace, CA · about 30 miles

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

    (909) 825-7693

  • Babcock Laboratories, Inc.

    Riverside, CA · about 31 miles

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

    (951) 653-3351

All 145 certified labs for California

Sources

PWSID CA3601048. Rebuilt from EPA data on Oct. 18, 2026.

Also in San Bernardino County

All California utilities

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