A84/100
NORTH MARIN WATER DISTRICT — Water Quality Report 2026
Serving 61,691 people · California
Water Source
Surface Water
County
—
System ID
CA2110003
Violations
1
Contaminant Test Results
2 contaminants above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Copper (90th percentile) | 1.95 mg/L | 1.30 mg/L | Over Limit |
chlorate | 240.00 µg/L | — | Above Goal |
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 1993.
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 NORTH MARIN WATER DISTRICT
Is NORTH MARIN WATER DISTRICT water safe to drink?
NORTH MARIN WATER DISTRICT water receives a grade of A (84/100), which is considered excellent. Out of 77 contaminants tested, 1 exceed EPA legal limits. 2 contaminant(s) exceed non-enforceable health goals. The water meets federal safety standards.
What contaminants has NORTH MARIN WATER DISTRICT detected?
77 contaminants were tested in NORTH MARIN WATER DISTRICT's water. Notable contaminants include Copper (90th percentile), chlorate. 1 exceed EPA legal limits (MCLs). 2 exceed EPA health goals (MCLGs).
Does NORTH MARIN WATER DISTRICT have any EPA violations?
Yes, NORTH MARIN WATER DISTRICT has 1 EPA violation(s) on record, with the most recent in 1993. Violation types include MCL. 1 are health-based violations.
How many people does NORTH MARIN WATER DISTRICT serve?
NORTH MARIN WATER DISTRICT serves approximately 61,691 people, California.
What type of water does NORTH MARIN WATER DISTRICT provide?
NORTH MARIN WATER DISTRICT sources its water from surface water. Surface water comes from rivers, lakes, or reservoirs and typically requires more extensive treatment. The utility's system ID is CA2110003.
How does NORTH MARIN WATER DISTRICT compare to other utilities in California?
NORTH MARIN WATER DISTRICT scores 84/100 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.