B75/100
GREAT OAKS WC INC — Water Quality Report 2026
Serving 110,088 people · California
Water Source
Groundwater
County
—
System ID
CA4310022
Violations
5
Contaminant Test Results
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
PFOS | 0.005 µg/L | 0.004 µg/L | Over Limit |
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 2015.
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 GREAT OAKS WC INC
Is GREAT OAKS WC INC water safe to drink?
GREAT OAKS WC INC water receives a grade of B (75/100), which is considered good. Out of 66 contaminants tested, 1 exceed EPA legal limits. 1 contaminant(s) exceed non-enforceable health goals. The water meets federal safety standards.
What contaminants has GREAT OAKS WC INC detected?
66 contaminants were tested in GREAT OAKS WC INC's water. Notable contaminants include PFOS. 1 exceed EPA legal limits (MCLs). 1 exceed EPA health goals (MCLGs).
Does GREAT OAKS WC INC have any EPA violations?
Yes, GREAT OAKS WC INC has 5 EPA violation(s) on record, with the most recent in 2015. Violation types include MCL, MR. 3 are health-based violations.
How many people does GREAT OAKS WC INC serve?
GREAT OAKS WC INC serves approximately 110,088 people, California.
What type of water does GREAT OAKS WC INC provide?
GREAT OAKS WC INC sources its water from groundwater. Groundwater is pumped from underground aquifers, which often provides natural filtration. The utility's system ID is CA4310022.
How does GREAT OAKS WC INC compare to other utilities in California?
GREAT OAKS WC INC scores 75/100 with a grade of B (good). This is an above-average performance for utilities statewide. Visit our California state page for a full comparison of water systems.