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MWD of So Cal Gene Plant

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
29 people
Connections
54
Water source
Surface water
Based in
La Verne, CA
County
San Bernardino
Owner
Private
The ZIP code it serves

92267

The short answer

Nothing in EPA’s and California’s records for this utility is above a health goal. That covers nitrate, arsenic and other regulated chemicals, plus lead and copper, not everything. No health-based violations on file since 2016.

What was found

Total trihalomethanes (TTHM) and haloacetic acids (HAA5): California’s own results, samples taken from March 31, 2020 to April 21, 2026, with EPA’s 2012 to 2019 file for earlier years.

Below EPA’s limits2

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

34.2ppb

Highest yearly average, 2020 to 2026

2026 average: 13 ppb

Averaged by year, the highest was 34.2 ppb, in 2022, below EPA’s legal limit of 80 ppb. Its highest single sample was 62 ppb. In 2026, the latest year on file, its eight samples averaged 13 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 39.8 ppb, in 2014.

What handles it

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

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

5.2ppb

Highest yearly average, 2020 to 2026

2026: not found

Averaged by year, the highest was 5.2 ppb, in 2020, below EPA’s legal limit of 60 ppb. Its highest single sample was 14 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 9.3 ppb, in 2014.

What handles it

No certification claim covers this compound yet.

One compound tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Lead

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) and haloacetic acids (HAA5) results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. MWD of So Cal Gene Plant’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 31, 2020 to April 21, 2026.

Testing your own tap

MWD of So Cal Gene Plant’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.

No lab California certifies is within 75 miles of the area MWD of So Cal Gene Plant serves on the state’s list. Some take samples by mail; the state’s page lists them all.

All 145 certified labs for California

Sources

PWSID CA3600383. Rebuilt from EPA data on Oct. 18, 2026.

Nearby

All California utilities

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