A85/100
OSHKOSH WATERWORKS — Water Quality Report 2026
Serving 63,000 people · Wisconsin
Water Source
Surface Water
County
—
System ID
WI4710457
Violations
8
Contaminant Test Results
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Lead (90th percentile) | 0.006 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
4
Violations (last 5yr)
2
Unresolved
1
Health-Related
TIER 3Unresolved
Reporting Violation
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
TIER 2Unresolved
Treatment technique violation
When: October 17, 2024Rule: Ground Water RuleEnforcement: Informal — resolved cooperativelyVerify on EPA.gov
TIER 3Resolved
Disinfection byproduct treatment technique failure
When: October 17, 2024 – June 30, 2025Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved
Failed Level 2 Assessment under Revised Total Coliform Rule
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: July 1, 2023 – September 30, 2023Rule: Stage 1 DBPREnforcement: 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 OSHKOSH WATERWORKS
Is OSHKOSH WATERWORKS water safe to drink?
OSHKOSH WATERWORKS water receives a grade of A (85/100), which is considered excellent. Out of 76 contaminants tested, none exceed EPA legal limits. 1 contaminant(s) exceed non-enforceable health goals. The water meets federal safety standards.
What contaminants has OSHKOSH WATERWORKS detected?
76 contaminants were tested in OSHKOSH WATERWORKS's water. Notable contaminants include Lead (90th percentile). No contaminants exceed EPA legal limits. 1 exceed EPA health goals (MCLGs).
Does OSHKOSH WATERWORKS have any EPA violations?
Yes, OSHKOSH WATERWORKS has 8 EPA violation(s) on record, with the most recent in 2025. Violation types include RPT, TT, Other. 1 are health-based violations.
How many people does OSHKOSH WATERWORKS serve?
OSHKOSH WATERWORKS serves approximately 63,000 people, Wisconsin. The system provides water to 1 community: Oshkosh.
What type of water does OSHKOSH WATERWORKS provide?
OSHKOSH WATERWORKS 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 WI4710457.
How does OSHKOSH WATERWORKS compare to other utilities in Wisconsin?
OSHKOSH WATERWORKS scores 85/100 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.