C49/100
GREEN LAKE WATERWORKS — Water Quality Report 2026
Serving 1,002 people · Wisconsin
Water Source
Groundwater
County
—
System ID
WI4240217
Violations
28
Contaminant Test Results
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Lead (90th percentile) | 0.001 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
5
Violations (last 5yr)
0
Unresolved
1
Health-Related
TIER 2Resolved
Treatment technique violation
When: October 17, 2024 – May 29, 2025Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved
Disinfection byproduct treatment technique failure
When: October 17, 2024 – April 7, 2025Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved
Monitoring / Reporting Violation
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: January 1, 2024 – January 12, 2024Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved
Surface water treatment technique failure
When: July 1, 2022 – October 14, 2022Enforcement: Resolving — corrective action underway
TIER 3Resolved
Surface water treatment technique failure
When: July 1, 2022 – October 14, 2022Enforcement: 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 GREEN LAKE WATERWORKS
Is GREEN LAKE WATERWORKS water safe to drink?
GREEN LAKE WATERWORKS water receives a grade of C (49/100), which is considered fair. 0 contaminant(s) exceed EPA legal limits and 28 violation(s) are on record. Customers may want to consider using a water filter.
What contaminants has GREEN LAKE WATERWORKS detected?
1 contaminants were tested in GREEN LAKE WATERWORKS's water. Notable contaminants include Lead (90th percentile). No contaminants exceed EPA legal limits. 1 exceed EPA health goals (MCLGs).
Does GREEN LAKE WATERWORKS have any EPA violations?
Yes, GREEN LAKE WATERWORKS has 28 EPA violation(s) on record, with the most recent in 2024. Violation types include TT, Other, MR. 5 are health-based violations.
How many people does GREEN LAKE WATERWORKS serve?
GREEN LAKE WATERWORKS serves approximately 1,002 people, Wisconsin. The system provides water to 1 community: Green Lake.
What type of water does GREEN LAKE WATERWORKS provide?
GREEN LAKE WATERWORKS sources its water from groundwater. Groundwater is pumped from underground aquifers, which often provides natural filtration. The utility's system ID is WI4240217.
How does GREEN LAKE WATERWORKS compare to other utilities in Wisconsin?
GREEN LAKE WATERWORKS scores 49/100 with a grade of C (fair). This score indicates room for improvement compared to other utilities. Visit our Wisconsin state page for a full comparison of water systems.