A88/100
Dupo Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 4,684 residents · Illinois
What's In Dupo's Tap Water?
31
Contaminants Tested
1
Exceed EPA Limits
0
Above EPA Goals
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
Water Utility Details
DUPO
Population Served
4,684
Water Source
Groundwater
System ID
IL1630350
Frequently Asked Questions About Dupo Water
Is Dupo tap water safe to drink?
Dupo, Illinois tap water receives a grade of A (88/100), which is considered excellent. Out of 31 contaminants tested, 1 exceed EPA maximum contaminant levels (MCLs) and 1 exceed health guidelines (MCLGs). While the water meets federal standards, some residents may still choose to use a filter for additional peace of mind.
What contaminants are in Dupo's water?
Of the 31 contaminants tested in Dupo's water supply, the most notable include PFOS. 1 contaminant(s) exceed EPA legal limits (MCLs). 1 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does Dupo have any water quality violations?
Yes, Dupo has 4 EPA violation(s) on record, with the most recent in 2024. Violation types include Other, MR. None of these are classified as health-based violations.
Do I need a water filter in Dupo?
Based on EPA data, using a water filter in Dupo is recommended. 1 contaminant(s) exceed legal limits. An NSF-certified filter — such as a reverse osmosis or activated carbon system — can effectively reduce many common contaminants. Choose a filter certified to remove the specific contaminants found in your area.
Where does Dupo's tap water come from?
Dupo's drinking water is sourced from groundwater and supplied by DUPO. The system serves approximately 4,684 people. Groundwater is pumped from underground aquifers, which often provides natural filtration.
How often is Dupo's water tested?
Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. Dupo's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.
How does Dupo's water compare to other cities in Illinois?
Dupo's water quality score of 88/100 earns a grade of A, which is considered excellent. This places Dupo among the better-performing water systems in Illinois. Visit our Illinois state page to see how all cities in the state compare.
What should I do if I'm concerned about Dupo's water quality?
If you have concerns about Dupo's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (DUPO) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.