Skip to content
TapBuff
ZIP

CSA 42 Oro Grande

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
533 people
Connections
144
Water source
Groundwater
Based in
San Bernardino, CA
County
San Bernardino
Owner
Local government
Hardness
Very hard
The ZIP code it serves

92368

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: Total trihalomethanes (TTHM), above the limit’s level, no violation. No health-based violations on file since 2016.

What handles it

What was found

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

Above the limit’s level, no violation recorded1

Total trihalomethanes (TTHM)

Forms or is added in treatment

Above the limit’s level, no violation

87.2ppb

Highest yearly average, 2021 to 2026

2026 average: 82 ppb

Averaged by year, the highest was 87.2 ppb, in 2023, above EPA’s legal limit of 80 ppb. Its highest single sample was 116 ppb. In 2026, the latest year on file, its four samples averaged 82 ppb, above the limit. EPA judges this limit on running averages at each sampling point, and recorded no violation for total trihalomethanes (TTHM) 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.

What handles it

  • NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
  • NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”

Above the health goal2

Arsenic

Comes from the source

Above the health goal

2.1ppb

Highest yearly average, 2021 to 2024

2024: not found

Averaged by year, the highest was 2.1 ppb, in 2021: below EPA’s legal limit of 10 ppb, but above its health goal of zero. Its highest single sample was 2.4 ppb. In 2024, 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 0.73 ppb, in 2018.

What handles it

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

Uranium

Comes from the source

Above the health goal

4.5ppb

Highest yearly average, 2021 to 2024

2024 average: 2.3 ppb

Averaged by year, the highest was 4.5 ppb, in 2021: below EPA’s legal limit of 30 ppb, but above its health goal of zero. In 2024, the latest year on file, its two samples averaged 2.3 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 5.8 ppb, in 2018.

What handles it

Below EPA’s limits3

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

28.8ppb

Highest yearly average, 2021 to 2026

Averaged by year, the highest was 28.8 ppb, in 2026, below EPA’s legal limit of 60 ppb. Its highest single sample was 42.3 ppb. That was also the latest year on file.

What handles it

No certification claim covers this compound yet.

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.57ppm

Highest yearly average, 2021 to 2024

2024 average: 0.45 ppm

Averaged by year, the highest was 0.57 ppm, in 2021, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 0.61 ppm. In 2024, the latest year on file, its two samples averaged 0.45 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.61 ppm, in 2015.

What handles it

Nitrate

Comes from the source

Below EPA’s limits

0.47ppm

Highest sample; found in 1 of 21

2026: not found

The highest sample, in 2022, was 0.47 ppm, below EPA’s legal limit of 10 ppm. 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 sample of 4.5 ppm, in 2012.

What handles it

  • NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
  • NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
2 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Chromium (total)
  • 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

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

    For: Total trihalomethanes (TTHM), Arsenic

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

  • NSF/ANSI 58

    Claims: Trihalomethanes (TTHM) Reduction, Arsenic (Pentavalent)<=50 ppb Reduction, Uranium

    For: Total trihalomethanes (TTHM), Arsenic, Uranium

    Other certifiers’ wording: 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

Very hard, typically 220 mg/L (12.9 grains per gallon), across 4 sampling points, 2019 to 2024.

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 12.9 grains per gallon, 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.

What this report can’t tell you

  • Everything else. Total trihalomethanes (TTHM), arsenic, uranium, haloacetic acids (HAA5), fluoride, nitrate and chromium (total) results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. CSA 42 Oro Grande’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 16, 2020 to May 13, 2026.

Testing your own tap

CSA 42 Oro Grande’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 CSA 42 Oro Grande serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Geo-Monitor, Inc

    Hesperia, CA · about 14 miles

    Certified for bacteria

    (760) 244-3481

  • BSK Associates - San Bernardino Analytical Laboratory

    San Bernardino, CA · about 41 miles

    Certified for bacteria

    (559) 497-2888

  • Clinical Laboratory of San Bernardino, Inc.

    Grand Terrace, CA · about 43 miles

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

    (909) 825-7693

All 145 certified labs for California

Sources

PWSID CA3600220. Rebuilt from EPA data on Oct. 18, 2026.

Also in San Bernardino County

All California utilities

What to do next