C59/100
LAKE IN THE HILLS — Water Quality Report 2026
Serving 28,661 people · Illinois
Water Source
Groundwater
County
—
System ID
IL1110400
Violations
14
Contaminant Test Results
2 contaminants above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Copper (90th percentile) | 1.40 mg/L | 1.30 mg/L | Over Limit |
Lead (90th percentile) | 0.003 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
2
Violations (last 5yr)
2
Unresolved
0
Health-Related
TIER 3Unresolved
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.
TIER 3Unresolved
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.
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 LAKE IN THE HILLS
Is LAKE IN THE HILLS water safe to drink?
LAKE IN THE HILLS water receives a grade of C (59/100), which is considered fair. 1 contaminant(s) exceed EPA legal limits and 14 violation(s) are on record. Customers may want to consider using a water filter.
What contaminants has LAKE IN THE HILLS detected?
67 contaminants were tested in LAKE IN THE HILLS's water. Notable contaminants include Copper (90th percentile), Lead (90th percentile). 1 exceed EPA legal limits (MCLs). 2 exceed EPA health goals (MCLGs).
Does LAKE IN THE HILLS have any EPA violations?
Yes, LAKE IN THE HILLS has 14 EPA violation(s) on record, with the most recent in 2025. Violation types include MR, MCL, Other. 4 are health-based violations.
How many people does LAKE IN THE HILLS serve?
LAKE IN THE HILLS serves approximately 28,661 people, Illinois. The system provides water to 1 community: Lake In The Hills.
What type of water does LAKE IN THE HILLS provide?
LAKE IN THE HILLS sources its water from groundwater. Groundwater is pumped from underground aquifers, which often provides natural filtration. The utility's system ID is IL1110400.
How does LAKE IN THE HILLS compare to other utilities in Illinois?
LAKE IN THE HILLS scores 59/100 with a grade of C (fair). This score indicates room for improvement compared to other utilities. Visit our Illinois state page for a full comparison of water systems.