C53/100
Modesto Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 1,394 residents · Illinois
What's In Modesto's Tap Water?
1
Contaminants Tested
0
Exceed EPA Limits
0
Above EPA Goals
EPA Violation History
5
Violations (last 5yr)
0
Unresolved
0
Health-Related
TIER 3Resolved
Monitoring Violation
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: March 1, 2025 – March 31, 2025Rule: Total Coliform 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: March 1, 2025 – March 31, 2025Rule: Stage 1 DBPREnforcement: Resolving — corrective action underway
TIER 3Resolved
Disinfection byproduct treatment technique failure
When: January 13, 2022 – March 28, 2022Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved
Disinfection byproduct treatment technique failure
When: January 13, 2022 – March 28, 2022Rule: Ground Water RuleEnforcement: 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: December 30, 2021 – May 6, 2022Rule: 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
NILWOOD
Population Served
1,394
Water Source
Purchased Surface Water
System ID
IL1170750
Frequently Asked Questions About Modesto Water
Is Modesto tap water safe to drink?
Modesto, Illinois tap water receives a grade of C (53/100), which is considered fair. 0 contaminant(s) exceed EPA maximum contaminant levels and 23 violation(s) are on record. Residents should consider using an NSF-certified water filter to reduce contaminant exposure.
What contaminants are in Modesto's water?
1 contaminants were tested in Modesto's water supply. No contaminants exceed EPA legal limits (MCLs) or health goals (MCLGs), which is a positive indicator of water quality.
Does Modesto have any water quality violations?
Yes, Modesto has 23 EPA violation(s) on record, with the most recent in 2025. Violation types include MON, MR, Other. 6 of these are health-based violations, which are the most serious category.
Do I need a water filter in Modesto?
Modesto water meets EPA standards, so a filter is not strictly necessary. However, some residents prefer the added security of a water filter. EPA health goals (MCLGs) are stricter than legal limits and are set at levels with zero expected health risk. All contaminants are within health goals.
Where does Modesto's tap water come from?
Modesto's drinking water is sourced from purchased surface water and supplied by NILWOOD. The system serves approximately 1,394 people. Surface water sources include rivers, lakes, and reservoirs.
How often is Modesto'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. Modesto'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 Modesto's water compare to other cities in Illinois?
Modesto's water quality score of 53/100 earns a grade of C, which is considered fair. This is a below-average score that indicates room for improvement. Visit our Illinois state page to see how all cities in the state compare.
What should I do if I'm concerned about Modesto's water quality?
If you have concerns about Modesto'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 (NILWOOD) 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.