F11/100
MADISON WATER UTILITY — Water Quality Report 2026
Serving 272,000 people · Wisconsin
Water Source
Groundwater
County
—
System ID
WI1130224
Violations
70
Contaminant Test Results
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Lead (90th percentile) | 0.002 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
2
Violations (last 5yr)
1
Unresolved
1
Health-Related
TIER 2Resolved
Treatment technique violation
When: October 17, 2024 – December 13, 2024Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 3Unresolved
Disinfection byproduct treatment technique failure
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 MADISON WATER UTILITY
Is MADISON WATER UTILITY water safe to drink?
MADISON WATER UTILITY water receives a grade of F (11/100), which is considered failing. 0 contaminant(s) exceed EPA legal limits and 70 violation(s) are on record. Customers may want to consider using a water filter.
What contaminants has MADISON WATER UTILITY detected?
73 contaminants were tested in MADISON WATER UTILITY's water. Notable contaminants include Lead (90th percentile). No contaminants exceed EPA legal limits. 1 exceed EPA health goals (MCLGs).
Does MADISON WATER UTILITY have any EPA violations?
Yes, MADISON WATER UTILITY has 70 EPA violation(s) on record, with the most recent in 2024. Violation types include TT, Other, MR. 4 are health-based violations.
How many people does MADISON WATER UTILITY serve?
MADISON WATER UTILITY serves approximately 272,000 people, Wisconsin. The system provides water to 1 community: Madison.
What type of water does MADISON WATER UTILITY provide?
MADISON WATER UTILITY sources its water from groundwater. Groundwater is pumped from underground aquifers, which often provides natural filtration. The utility's system ID is WI1130224.
How does MADISON WATER UTILITY compare to other utilities in Wisconsin?
MADISON WATER UTILITY scores 11/100 with a grade of F (failing). This score suggests significant water quality concerns relative to other utilities. Visit our Wisconsin state page for a full comparison of water systems.