F0/100
WONDER LAKE — Water Quality Report 2026
Serving 3,870 people · Illinois
Water Source
Groundwater
County
—
System ID
IL1115750
Violations
86
Contaminant Test Results
2 contaminants above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Copper (90th percentile) | 1.90 mg/L | 1.30 mg/L | Over Limit |
Lead (90th percentile) | 0.003 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
5
Violations (last 5yr)
1
Unresolved
1
Health-Related
TIER 3Unresolved
Failed to issue ongoing public notification
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: July 1, 2025Rule: Ground Water RuleEnforcement: Informal — resolved cooperativelyVerify on EPA.gov
TIER 3Resolved
Monitoring / Reporting Violation
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: April 1, 2025 – August 27, 2025Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved
Disinfection byproduct treatment technique failure
When: February 10, 2024 – April 8, 2024Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 2Resolved
Consumer confidence report — content deficiency
When: April 2, 2023 – June 22, 2023Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved
Exceeded the MCL for disinfection byproducts
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: January 1, 2022 – December 31, 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 WONDER LAKE
Is WONDER LAKE water safe to drink?
WONDER LAKE water receives a grade of F (0/100), which is considered failing. 1 contaminant(s) exceed EPA legal limits and 86 violation(s) are on record. Customers may want to consider using a water filter.
What contaminants has WONDER LAKE detected?
32 contaminants were tested in WONDER LAKE's water. Notable contaminants include Copper (90th percentile), Lead (90th percentile). 1 exceed EPA legal limits (MCLs). 2 exceed EPA health goals (MCLGs).
Does WONDER LAKE have any EPA violations?
Yes, WONDER LAKE has 86 EPA violation(s) on record, with the most recent in 2025. Violation types include MR, Other, TT. 2 are health-based violations.
How many people does WONDER LAKE serve?
WONDER LAKE serves approximately 3,870 people, Illinois.
What type of water does WONDER LAKE provide?
WONDER LAKE sources its water from groundwater. Groundwater is pumped from underground aquifers, which often provides natural filtration. The utility's system ID is IL1115750.
How does WONDER LAKE compare to other utilities in Illinois?
WONDER LAKE scores 0/100 with a grade of F (failing). This score suggests significant water quality concerns relative to other utilities. Visit our Illinois state page for a full comparison of water systems.