A87/100
CWSC OAK HILLS — Water Quality Report 2026
Serving 3,161 people · California
Water Source
Groundwater
County
—
System ID
CA2710019
Violations
5
Contaminant Test Results
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 2005.
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 CWSC OAK HILLS
Is CWSC OAK HILLS water safe to drink?
CWSC OAK HILLS water receives a grade of A (87/100), which is considered excellent. Out of 31 contaminants tested, none exceed EPA legal limits. The water meets federal safety standards.
What contaminants has CWSC OAK HILLS detected?
31 contaminants were tested in CWSC OAK HILLS's water. No contaminants exceed EPA legal limits or health goals, indicating good water quality management.
Does CWSC OAK HILLS have any EPA violations?
Yes, CWSC OAK HILLS has 5 EPA violation(s) on record, with the most recent in 2005. Violation types include MR, MCL. 2 are health-based violations.
How many people does CWSC OAK HILLS serve?
CWSC OAK HILLS serves approximately 3,161 people, California.
What type of water does CWSC OAK HILLS provide?
CWSC OAK HILLS sources its water from groundwater. Groundwater is pumped from underground aquifers, which often provides natural filtration. The utility's system ID is CA2710019.
How does CWSC OAK HILLS compare to other utilities in California?
CWSC OAK HILLS scores 87/100 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.