F17/100
Monmouth Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 12,177 residents · Illinois
What's In Monmouth's Tap Water?
31
Contaminants Tested
0
Exceed EPA Limits
0
Above EPA Goals
EPA Violation History
2
Violations (last 5yr)
0
Unresolved
1
Health-Related
TIER 3Resolved
Disinfection byproduct treatment technique failure
When: November 28, 2024 – November 20, 2024Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 2Resolved
Exceeded the Maximum Contaminant Level (running average)
When: October 1, 2024 – December 31, 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
Frequently Asked Questions About Monmouth Water
Is Monmouth tap water safe to drink?
Monmouth, Illinois tap water receives a grade of F (17/100), which is considered failing. 1 contaminant(s) exceed EPA maximum contaminant levels and 49 violation(s) are on record. Residents should consider using an NSF-certified water filter to reduce contaminant exposure.
What contaminants are in Monmouth's water?
Of the 31 contaminants tested in Monmouth's water supply, the most notable include PFOA. 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 Monmouth have any water quality violations?
Yes, Monmouth has 49 EPA violation(s) on record, with the most recent in 2025. Violation types include Other, MCL, MR. 39 of these are health-based violations, which are the most serious category.
Do I need a water filter in Monmouth?
Based on EPA data, using a water filter in Monmouth 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 Monmouth's tap water come from?
Monmouth's drinking water is sourced from purchased groundwater and supplied by ABINGDON and 1 other water system(s). The system serves approximately 12,177 people. Groundwater is pumped from underground aquifers, which often provides natural filtration.
How often is Monmouth'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. Monmouth'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 Monmouth's water compare to other cities in Illinois?
Monmouth's water quality score of 17/100 earns a grade of F, which is considered failing. This is a concerning score that suggests significant water quality issues. Visit our Illinois state page to see how all cities in the state compare.
What should I do if I'm concerned about Monmouth's water quality?
If you have concerns about Monmouth'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 (ABINGDON) 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.