A97/100
CITY OF THOUSAND OAKS WATER DEPARTMENT — Water Quality Report 2026
Serving 53,157 people · California
Water Source
Purchased Surface Water
County
—
System ID
CA5610020
Violations
0
Contaminant Test Results
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Copper (90th percentile) | 287.00 mg/L | 1.30 mg/L | Over Limit |
EPA Violation History
No violations in the past 5 years
This system has a clean compliance history.
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Frequently Asked Questions About CITY OF THOUSAND OAKS WATER DEPARTMENT
Is CITY OF THOUSAND OAKS WATER DEPARTMENT water safe to drink?
CITY OF THOUSAND OAKS WATER DEPARTMENT water receives a grade of A (97/100), which is considered excellent. Out of 77 contaminants tested, 1 exceed EPA legal limits. 1 contaminant(s) exceed non-enforceable health goals. The water meets federal safety standards.
What contaminants has CITY OF THOUSAND OAKS WATER DEPARTMENT detected?
77 contaminants were tested in CITY OF THOUSAND OAKS WATER DEPARTMENT's water. Notable contaminants include Copper (90th percentile). 1 exceed EPA legal limits (MCLs). 1 exceed EPA health goals (MCLGs).
Does CITY OF THOUSAND OAKS WATER DEPARTMENT have any EPA violations?
No, CITY OF THOUSAND OAKS WATER DEPARTMENT has zero EPA violations on record. This indicates consistent compliance with federal drinking water standards.
How many people does CITY OF THOUSAND OAKS WATER DEPARTMENT serve?
CITY OF THOUSAND OAKS WATER DEPARTMENT serves approximately 53,157 people, California.
What type of water does CITY OF THOUSAND OAKS WATER DEPARTMENT provide?
CITY OF THOUSAND OAKS WATER DEPARTMENT sources its water from purchased surface water. Surface water comes from rivers, lakes, or reservoirs and typically requires more extensive treatment. The utility's system ID is CA5610020.
How does CITY OF THOUSAND OAKS WATER DEPARTMENT compare to other utilities in California?
CITY OF THOUSAND OAKS WATER DEPARTMENT scores 97/100 with a grade of A (excellent). This places it among the higher-performing utilities in the state. Visit our California state page for a full comparison of water systems.