Tap WaterIndex

← California

Tap water quality report

Westborough Water District

EPA monitoring tested this supplier for 42 contaminants and detected 11. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

42
contaminants tested
11
detected
13,486
people served
3
health-based violations
California rankingsLead in CaliforniaPFAS in California
Water source
SWP
Ownership
Local government
Counties served
San Mateo

Compliance record

Formal violations the EPA has on file for this supplier. A health-based violation means a contaminant limit or a required treatment was breached; the rest are monitoring or reporting failures — still violations, but not a measured health risk.

3
health-based violations
3
violations on file
0
still open
ViolationTypeStatusPeriod
MCL Health-based Resolved 1998-07-01 → 1998-07-31
MCL Health-based Resolved 1998-07-01 → 1998-07-31
TT Health-based Resolved 1991-10-01 → 1998-07-31

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
Chloroform
61.8 µg/L
No EPA limit set
 124/124 SYR4 2012–2019
Dichloroacetic Acid
25.5 µg/L
No EPA limit set
 124/124 SYR4 2012–2019
TTHM
63.6 µg/L 80%
of the EPA limit 80 µg/L
 124/124 SYR4 2012–2019
Total Haloacetic Acids (HAA5)
52.6 µg/L 88%
of the EPA limit 60 µg/L
 124/124 SYR4 2012–2019
Bromodichloromethane
8.2 µg/L
No EPA limit set
 122/124 SYR4 2012–2019
Trichloroacetic Acid
24.8 µg/L
No EPA limit set
 113/124 SYR4 2012–2019
Dibromochloromethane
4.6 µg/L
No EPA limit set
 98/124 SYR4 2012–2019
Lead
0.0 mg/L 0%
of the EPA limit 0.0150 mg/L
 44/44 LCR 2025
Monochloroacetic Acid
3.3 µg/L
No EPA limit set
 33/124 SYR4 2012–2019
Bromoform
0.7000 µg/L
No EPA limit set
 4/124 SYR4 2012–2019
Dibromoacetic Acid
1.3 µg/L
No EPA limit set
 4/124 SYR4 2012–2019
31 contaminants tested, none detected
11Cl-PF3OUdS4:2 Fts6:2 Fts8:2 Fts9Cl-PF3ONSAdonaHfpo-DaMonobromoacetic AcidNetfosaaNfdhaNmefosaaPfbaPFBSPfdaPfdoaPfeesaPfhpaPfhpsPfhxaPFHXSPfmbaPfmpaPFNAPFOAPFOSPfpeaPfpesPftaPftrdaPfunaLithium

Utility contact

Contact
MAIRENA, PATRICIA
Phone
650-589-1435
Email
pmairena@westboroughwater.org

Frequently asked questions about Westborough Water District

Is Westborough Water District tap water safe to drink?

EPA monitoring detected 11 contaminants in Westborough Water District'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 Westborough Water District's water?

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

How many people does Westborough Water District serve?

Westborough Water District reports serving 13,486 people in California, per its EPA record.

Has Westborough Water District had any water quality violations?

The EPA has 3 violations on file for Westborough Water District, of which 3 are health-based (a contaminant limit or required treatment was breached) and 0 remain open. The rest are monitoring or reporting failures.

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.