A89/100
CITY OF COLUSA — Water Quality Report 2026
Serving 6,447 people · California
Water Source
Groundwater
County
—
System ID
CA0610002
Violations
4
Contaminant Test Results
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Lead (90th percentile) | 0.007 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
2
Violations (last 5yr)
0
Unresolved
0
Health-Related
TIER 3Resolved
Monitoring Violation
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: March 1, 2022 – March 31, 2022Rule: Total Coliform RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved
Monitoring Violation
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: January 1, 2022 – March 31, 2022Rule: Total Coliform RuleEnforcement: Resolving — corrective action underway
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 COLUSA
Is CITY OF COLUSA water safe to drink?
CITY OF COLUSA water receives a grade of A (89/100), which is considered excellent. Out of 51 contaminants tested, none exceed EPA legal limits. 1 contaminant(s) exceed non-enforceable health goals. The water meets federal safety standards.
What contaminants has CITY OF COLUSA detected?
51 contaminants were tested in CITY OF COLUSA's water. Notable contaminants include Lead (90th percentile). No contaminants exceed EPA legal limits. 1 exceed EPA health goals (MCLGs).
Does CITY OF COLUSA have any EPA violations?
Yes, CITY OF COLUSA has 4 EPA violation(s) on record, with the most recent in 2022. Violation types include MON, MCL. 1 are health-based violations.
How many people does CITY OF COLUSA serve?
CITY OF COLUSA serves approximately 6,447 people, California. The system provides water to 1 community: Colusa.
What type of water does CITY OF COLUSA provide?
CITY OF COLUSA sources its water from groundwater. Groundwater is pumped from underground aquifers, which often provides natural filtration. The utility's system ID is CA0610002.
How does CITY OF COLUSA compare to other utilities in California?
CITY OF COLUSA scores 89/100 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.