A83/100
COTTAGE GROVE WATERWORKS — Water Quality Report 2026
Serving 9,345 people · Wisconsin
Water Source
Groundwater
County
—
System ID
WI1130218
Violations
6
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 – February 24, 2025Rule: 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 COTTAGE GROVE WATERWORKS
Is COTTAGE GROVE WATERWORKS water safe to drink?
COTTAGE GROVE WATERWORKS water receives a grade of A (83/100), 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 COTTAGE GROVE WATERWORKS detected?
51 contaminants were tested in COTTAGE GROVE WATERWORKS's water. Notable contaminants include Lead (90th percentile). No contaminants exceed EPA legal limits. 1 exceed EPA health goals (MCLGs).
Does COTTAGE GROVE WATERWORKS have any EPA violations?
Yes, COTTAGE GROVE WATERWORKS has 6 EPA violation(s) on record, with the most recent in 2024. Violation types include TT, Other, MR. 2 are health-based violations.
How many people does COTTAGE GROVE WATERWORKS serve?
COTTAGE GROVE WATERWORKS serves approximately 9,345 people, Wisconsin. The system provides water to 1 community: Cottage Grove.
What type of water does COTTAGE GROVE WATERWORKS provide?
COTTAGE GROVE WATERWORKS sources its water from groundwater. Groundwater is pumped from underground aquifers, which often provides natural filtration. The utility's system ID is WI1130218.
How does COTTAGE GROVE WATERWORKS compare to other utilities in Wisconsin?
COTTAGE GROVE WATERWORKS scores 83/100 with a grade of A (excellent). This places it among the higher-performing utilities in the state. Visit our Wisconsin state page for a full comparison of water systems.