Monmouth, Illinois Water Quality Report
Water quality data for 4 water systems serving 12,734 people.
Water Source
Detected Contaminants
| Contaminant | Detected Level | EPA Limit (MCL) | Health Guideline | % of Limit | Status |
|---|---|---|---|---|---|
| lithium | 230.0 | No federal limit | 10.0 ug/L(EPA/USGS HBSL) | 2300% | Above guideline |
| PFBA | 0.050 | No federal limit | 1000.0 ug/L(EWG) | 0% | Below guideline |
| PFBS | 0.004 | No federal limit | 2000.0 ug/L(EPA Health Advisory) | 0% | Below guideline |
| PFOA | 0.009 | 0.004 ug/L | 0.090 ug/L(EWG) | 235% | Above limit |
| PFOS | 0.005 | 0.004 ug/L | 0.300 ug/L(EWG) | 120% | Above limit |
| PFPeA | 0.010 | No federal limit | 1000.0 ug/L(EWG) | 0% | Below guideline |
Recommended Water Filters
Based on the contaminants detected in your water supply, these filtration systems are recommended:
Reverse Osmosis (RO)
Reverse osmosis systems remove up to 99% of PFAS compounds. Recommended for homes with detected PFAS.
Up to 99% PFAS removal
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Compliance & Violations
Active Violations (95)
52
Jul 1, 2025
72
Jul 1, 2025
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Resolved Violations (383)
75
Nov 28, 2024
75
Nov 28, 2024
02
Oct 1, 2024 — Dec 31, 2024
02
Oct 1, 2024 — Dec 31, 2024
02
Oct 1, 2024 — Dec 31, 2024
+ 378 more resolved violations
Frequently Asked Questions
Is Monmouth tap water safe to drink?
Monmouth's water has 2 contaminants detected above EPA limits. While the water is treated, residents may want to consider additional filtration.
What contaminants are in Monmouth tap water?
6 contaminants have been detected in Monmouth's water supply across 4 water systems. See the full contaminant table above for details.
How can I improve my water quality in Monmouth?
Install a water filter rated for the specific contaminants found in Monmouth's water. See our filter recommendations above. You can also request your utility's Consumer Confidence Report for the most current test results.
Does Monmouth have any water quality violations?
Yes, Monmouth currently has 95 active violations. See the violations section above for details.