B77/100
OCONTO WATERWORKS — Water Quality Report 2026
Serving 4,610 people · Wisconsin
Water Source
Groundwater
County
—
System ID
WI4430495
Violations
8
Contaminant Test Results
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Lead (90th percentile) | 0.003 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
2
Violations (last 5yr)
0
Unresolved
1
Health-Related
TIER 2Resolved
Treatment technique violation
When: October 17, 2024 – May 27, 2025Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved
Disinfection byproduct treatment technique failure
When: October 17, 2024 – June 30, 2025Rule: Ground Water 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 OCONTO WATERWORKS
Is OCONTO WATERWORKS water safe to drink?
OCONTO WATERWORKS water receives a grade of B (77/100), which is considered good. Out of 31 contaminants tested, none exceed EPA legal limits. 1 contaminant(s) exceed non-enforceable health goals. The water meets federal safety standards.
What contaminants has OCONTO WATERWORKS detected?
31 contaminants were tested in OCONTO WATERWORKS's water. Notable contaminants include Lead (90th percentile). No contaminants exceed EPA legal limits. 1 exceed EPA health goals (MCLGs).
Does OCONTO WATERWORKS have any EPA violations?
Yes, OCONTO WATERWORKS has 8 EPA violation(s) on record, with the most recent in 2024. Violation types include TT, Other, MCL. 3 are health-based violations.
How many people does OCONTO WATERWORKS serve?
OCONTO WATERWORKS serves approximately 4,610 people, Wisconsin. The system provides water to 1 community: Oconto.
What type of water does OCONTO WATERWORKS provide?
OCONTO WATERWORKS sources its water from groundwater. Groundwater is pumped from underground aquifers, which often provides natural filtration. The utility's system ID is WI4430495.
How does OCONTO WATERWORKS compare to other utilities in Wisconsin?
OCONTO WATERWORKS scores 77/100 with a grade of B (good). This is an above-average performance for utilities statewide. Visit our Wisconsin state page for a full comparison of water systems.