C46/100
DEKALB — Water Quality Report 2026
Serving 45,000 people · Illinois
Water Source
Groundwater
County
—
System ID
IL0370100
Violations
15
Contaminant Test Results
2 contaminants above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Copper (90th percentile) | 1.70 mg/L | 1.30 mg/L | Over Limit |
Lead (90th percentile) | 0.011 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
2
Violations (last 5yr)
1
Unresolved
0
Health-Related
TIER 3Unresolved
Surface water treatment technique failure
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 DEKALB
Is DEKALB water safe to drink?
DEKALB water receives a grade of C (46/100), which is considered fair. 1 contaminant(s) exceed EPA legal limits and 15 violation(s) are on record. Customers may want to consider using a water filter.
What contaminants has DEKALB detected?
67 contaminants were tested in DEKALB's water. Notable contaminants include Copper (90th percentile), Lead (90th percentile). 1 exceed EPA legal limits (MCLs). 2 exceed EPA health goals (MCLGs).
Does DEKALB have any EPA violations?
Yes, DEKALB has 15 EPA violation(s) on record, with the most recent in 2025. Violation types include Other, MR, MON. 7 are health-based violations.
How many people does DEKALB serve?
DEKALB serves approximately 45,000 people, Illinois. The system provides water to 1 community: De Kalb.
What type of water does DEKALB provide?
DEKALB sources its water from groundwater. Groundwater is pumped from underground aquifers, which often provides natural filtration. The utility's system ID is IL0370100.
How does DEKALB compare to other utilities in Illinois?
DEKALB scores 46/100 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.