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Golden State Water Co - Morongo del Sur

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
1,715 people
Connections
836
Water source
Groundwater
Based in
Apple Valley, CA
County
San Bernardino
Owner
Private
Hardness
Very hard
The ZIP code it serves

92256

The short answer

2 results are 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

Lead and copper: EPA SDWIS monitoring periods ending 2004 to 2025.

Uranium, fluoride, nitrate, total trihalomethanes (TTHM), arsenic, chromium (total) and haloacetic acids (HAA5): California’s own results, samples taken from Jan. 7, 2020 to July 8, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the health goal2

Uranium

Comes from the source

Above the health goal

20.5ppb

Highest yearly average, 2020 to 2026

2026 average: 11.1 ppb

Averaged by year, the highest was 20.5 ppb, in 2023: below EPA’s legal limit of 30 ppb, but above its health goal of zero. Its highest single sample was 50.7 ppb. In 2026, the latest year on file, its 35 samples averaged 11.1 ppb. EPA recorded no violation for uranium at this utility since 2020. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 26.6 ppb, in 2012.

What handles it

Lead

Comes from pipes, often your own

Above the health goal

0.66ppb

90th percentile, 2023 to 2025

In the latest period, 9 in 10 homes sampled were at or below 0.66 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 limits3

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.7ppm

Highest yearly average, 2020 to 2026

Averaged by year, the highest was 0.7 ppm, in 2026, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 0.8 ppm. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.75 ppm, in 2017.

What handles it

Nitrate

Comes from the source

Below EPA’s limits

0.58ppm

Highest sample; found in 15 of 26

2026 average: 0.36 ppm

The highest sample, in 2023, was 0.58 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, its four samples averaged 0.36 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 0.72 ppm, in 2013.

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

3.5ppb

Highest yearly average, 2020 to 2025

2025 average: 1.6 ppb

Averaged by year, the highest was 3.5 ppb, in 2022, below EPA’s legal limit of 80 ppb. Its highest single sample was 5.7 ppb. In 2025, the latest year on file, its two samples averaged 1.6 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 2.4 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.
  • Arsenic
  • Chromium (total)
  • Haloacetic acids (HAA5)

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

Very hard, typically 270 mg/L (15.8 grains per gallon), across 3 sampling points, 2020 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 15.8 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. Uranium, fluoride, nitrate, total trihalomethanes (TTHM), 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. Golden State Water Co - Morongo del Sur’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 Jan. 7, 2020 to July 8, 2026.

Testing your own tap

Golden State Water Co - Morongo del Sur’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 Golden State Water Co - Morongo del Sur 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 38 miles

    Certified for bacteria

    (559) 497-2888

  • Babcock Laboratories, Inc.

    Riverside, CA · about 41 miles

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

    (951) 653-3351

  • Clinical Laboratory of San Bernardino, Inc.

    Grand Terrace, CA · about 41 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 CA3610063. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in San Bernardino County

All California utilities

What to do next