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Tap water quality report

California Water Service Co - Westlake

EPA monitoring tested this supplier for 43 contaminants and detected 13. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

43
contaminants tested
13
detected
19,533
people served
0
health-based violations
California rankingsLead in CaliforniaPFAS in California
Water source
SWP
Ownership
Private
Counties served
Ventura

Compliance record

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

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
Total Haloacetic Acids (HAA5)
33 µg/L 55%
of the EPA limit 60 µg/L
 130/131 SYR4 2012–2019
Bromodichloromethane
25.36 µg/L
No EPA limit set
 129/129 SYR4 2012–2019
Bromoform
26.99 µg/L
No EPA limit set
 129/129 SYR4 2012–2019
Dibromochloromethane
33.14 µg/L
No EPA limit set
 129/129 SYR4 2012–2019
TTHM
92.1 µg/L 115%
of the EPA limit, in the worst sample — 80 µg/L
 129/129 SYR4 2012–2019
Dibromoacetic Acid
14 µg/L
No EPA limit set
 128/131 SYR4 2012–2019
Chloroform
12.21 µg/L
No EPA limit set
 126/129 SYR4 2012–2019
Dichloroacetic Acid
15 µg/L
No EPA limit set
 119/131 SYR4 2012–2019
Lead
0.0030 mg/L 20%
of the EPA limit 0.0150 mg/L
 37/37 LCR 2024
Trichloroacetic Acid
15 µg/L
No EPA limit set
 27/131 SYR4 2012–2019
Monobromoacetic Acid
5.6 µg/L
No EPA limit set
 13/131 SYR4 2012–2019
Lithium
13.8 µg/L
No EPA limit set
 4/4 UCMR-5 2024
Monochloroacetic Acid
4.9 µg/L
No EPA limit set
 3/131 SYR4 2012–2019
30 contaminants tested, none detected
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Utility contact

Contact
JAMES, SOPHIE
Phone
408-367-8593
Email
sjames@calwater.com

Frequently asked questions about California Water Service Co - Westlake

Is California Water Service Co - Westlake tap water safe to drink?

EPA monitoring detected 13 contaminants in California Water Service Co - Westlake'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 California Water Service Co - Westlake's water?

EPA monitoring detected Total Haloacetic Acids (HAA5), Bromodichloromethane, Bromoform, Dibromochloromethane, TTHM, and others. The full list with the level and data source for each is above.

How many people does California Water Service Co - Westlake serve?

California Water Service Co - Westlake reports serving 19,533 people in California, per its EPA record.

Has California Water Service Co - Westlake had any water quality violations?

The EPA has no formal drinking-water violations on file for California Water Service Co - Westlake.

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.