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Tap water quality report

Gswc-South San Gabriel

EPA monitoring tested this supplier for 44 contaminants and detected 15. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

44
contaminants tested
15
detected
26,240
people served
0
health-based violations
California rankingsLead in CaliforniaPFAS in California
Water source
SWP
Ownership
Private
Counties served
Los Angeles

Compliance record

No violations on file. The EPA has no formal drinking-water violations recorded for this supplier.

PFAS detected

PFAS are industrial “forever chemicals”. These are the EPA's latest nationwide test results (2023–2025).
ContaminantMaxDetection ratePeriod
Pfba 0.0056 µg/L 1/8 2024

Other contaminants detected

Each bar shows the measured level as a share of the EPA limit: green is well under, amber is close to it, red is over. For lead and copper the limit applies to exactly the 90th-percentile figure shown, so red there means a real exceedance. For everything else the limit applies to a running annual average while the figure is the single worst sample on record — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately.
ContaminantLevel vs EPA limitDetection rateSourcePeriod
TTHM
30 µg/L 38%
of the EPA limit 80 µg/L
 94/661 SYR4 2012–2019
Dibromochloromethane
10 µg/L
No EPA limit set
 55/672 SYR4 2012–2019
Bromodichloromethane
9.4 µg/L
No EPA limit set
 37/672 SYR4 2012–2019
Lead
0.0 mg/L 0%
of the EPA limit 0.0150 mg/L
 33/33 LCR 2023
Bromoform
3.7 µg/L
No EPA limit set
 27/672 SYR4 2012–2019
Total Haloacetic Acids (HAA5)
16 µg/L 27%
of the EPA limit 60 µg/L
 23/124 SYR4 2012–2019
Chloroform
11 µg/L
No EPA limit set
 19/672 SYR4 2012–2019
Dibromoacetic Acid
2.8 µg/L
No EPA limit set
 19/124 SYR4 2012–2019
Dichloroacetic Acid
8.8 µg/L
No EPA limit set
 10/124 SYR4 2012–2019
Trichloroacetic Acid
4.7 µg/L
No EPA limit set
 6/124 SYR4 2012–2019
Monochloroacetic Acid
2.7 µg/L
No EPA limit set
 4/124 SYR4 2012–2019
Lithium
57 µg/L
No EPA limit set
 4/8 UCMR-5 2024
Copper
190 µg/L 15%
of the EPA limit 1300 µg/L
 1/14 SYR4 2012–2019
Lead
17 µg/L 113%
of the EPA limit, in the worst sample — 15 µg/L
 1/4 SYR4 2012–2019
29 contaminants tested, none detected
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Utility contact

Contact
ZAKHARI, GEORGE
Phone
760-515-8322
Email
George.Zakhari@gswater.com

Frequently asked questions about Gswc-South San Gabriel

Is Gswc-South San Gabriel tap water safe to drink?

EPA monitoring detected 15 contaminants in Gswc-South San Gabriel's water. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and the utility's annual Consumer Confidence Report for its official compliance status.

What contaminants were detected in Gswc-South San Gabriel's water?

EPA monitoring detected TTHM, Dibromochloromethane, Bromodichloromethane, Lead, Bromoform, and others. The full list with the level and data source for each is above.

How many people does Gswc-South San Gabriel serve?

Gswc-South San Gabriel reports serving 26,240 people in California, per its EPA record.

Has Gswc-South San Gabriel had any water quality violations?

The EPA has no formal drinking-water violations on file for Gswc-South San Gabriel.

Where does this data come from?

Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.