B71/100
Thomasboro Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 1,066 residents · Illinois
What's In Thomasboro's Tap Water?
9
Contaminants Tested
1
Exceed EPA Limits
0
Above EPA Goals
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Copper (90th percentile) | 1.73 mg/L | 1.30 mg/L | Over Limit |
EPA Violation History
5
Violations (last 5yr)
1
Unresolved
0
Health-Related
TIER 3Unresolved
Surface water treatment technique failure
TIER 3Resolved
Disinfection byproduct treatment technique failure
When: January 12, 2025 – June 20, 2024Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved
Failed Level 2 Assessment under Revised Total Coliform Rule
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: October 1, 2023 – December 31, 2023Rule: Stage 2 DBPREnforcement: Resolving — corrective action underway
TIER 3Resolved
Failed Level 2 Assessment under Revised Total Coliform Rule
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: October 1, 2023 – December 31, 2023Rule: Stage 2 DBPREnforcement: Resolving — corrective action underway
TIER 3Resolved
Monitoring / Reporting Violation
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: September 29, 2021 – October 26, 2021Rule: Ground Water RuleEnforcement: 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
THOMASBORO
Population Served
1,066
Water Source
Groundwater
System ID
IL0190950
Frequently Asked Questions About Thomasboro Water
Is Thomasboro tap water safe to drink?
Thomasboro, Illinois tap water receives a grade of B (71/100), which is considered good. Out of 9 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 Thomasboro's water?
Of the 9 contaminants tested in Thomasboro's water supply, the most notable include Copper (90th percentile). 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 Thomasboro have any water quality violations?
Yes, Thomasboro has 17 EPA violation(s) on record, with the most recent in 2025. Violation types include Other, MR, MCL. 1 of these are health-based violations, which are the most serious category.
Do I need a water filter in Thomasboro?
Based on EPA data, using a water filter in Thomasboro 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 Thomasboro's tap water come from?
Thomasboro's drinking water is sourced from groundwater and supplied by THOMASBORO. The system serves approximately 1,066 people. Groundwater is pumped from underground aquifers, which often provides natural filtration.
How often is Thomasboro'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. Thomasboro'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 Thomasboro's water compare to other cities in Illinois?
Thomasboro's water quality score of 71/100 earns a grade of B, which is considered good. This is an above-average score compared to many cities nationwide. Visit our Illinois state page to see how all cities in the state compare.
What should I do if I'm concerned about Thomasboro's water quality?
If you have concerns about Thomasboro'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 (THOMASBORO) 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.