A99/100
GSWC - NORWALK — Water Quality Report 2026
Serving 43,176 people · California
Water Source
Purchased Surface Water
County
—
System ID
CA1910098
Violations
1
Contaminant Test Results
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 1988.
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 GSWC - NORWALK
Is GSWC - NORWALK water safe to drink?
GSWC - NORWALK water receives a grade of A (99/100), which is considered excellent. Out of 69 contaminants tested, none exceed EPA legal limits. The water meets federal safety standards.
What contaminants has GSWC - NORWALK detected?
69 contaminants were tested in GSWC - NORWALK's water. No contaminants exceed EPA legal limits or health goals, indicating good water quality management.
Does GSWC - NORWALK have any EPA violations?
Yes, GSWC - NORWALK has 1 EPA violation(s) on record, with the most recent in 1988. Violation types include Other.
How many people does GSWC - NORWALK serve?
GSWC - NORWALK serves approximately 43,176 people, California.
What type of water does GSWC - NORWALK provide?
GSWC - NORWALK 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 CA1910098.
How does GSWC - NORWALK compare to other utilities in California?
GSWC - NORWALK scores 99/100 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.