A88/100
DUPO — Water Quality Report 2026
Serving 4,684 people · Illinois
Water Source
Groundwater
County
—
System ID
IL1630350
Violations
4
Contaminant Test Results
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
PFOS | 0.004 µg/L | 0.004 µg/L | Over Limit |
EPA Violation History
1
Violation (last 5yr)
0
Unresolved
0
Health-Related
TIER 3Resolved
Surface water treatment technique failure
When: July 1, 2024 – October 28, 2024Enforcement: 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 DUPO
Is DUPO water safe to drink?
DUPO water receives a grade of A (88/100), which is considered excellent. Out of 31 contaminants tested, 1 exceed EPA legal limits. 1 contaminant(s) exceed non-enforceable health goals. The water meets federal safety standards.
What contaminants has DUPO detected?
31 contaminants were tested in DUPO's water. Notable contaminants include PFOS. 1 exceed EPA legal limits (MCLs). 1 exceed EPA health goals (MCLGs).
Does DUPO have any EPA violations?
Yes, DUPO has 4 EPA violation(s) on record, with the most recent in 2024. Violation types include Other, MR.
How many people does DUPO serve?
DUPO serves approximately 4,684 people, Illinois. The system provides water to 1 community: Dupo.
What type of water does DUPO provide?
DUPO sources its water from groundwater. Groundwater is pumped from underground aquifers, which often provides natural filtration. The utility's system ID is IL1630350.
How does DUPO compare to other utilities in Illinois?
DUPO scores 88/100 with a grade of A (excellent). This places it among the higher-performing utilities in the state. Visit our Illinois state page for a full comparison of water systems.