B67/100
WOODSTOCK — Water Quality Report 2026
Serving 25,630 people · Illinois
Water Source
Groundwater
County
—
System ID
IL1110950
Violations
10
Contaminant Test Results
2 contaminants above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Copper (90th percentile) | 1.50 mg/L | 1.30 mg/L | Over Limit |
Lead (90th percentile) | 0.011 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
4
Violations (last 5yr)
0
Unresolved
1
Health-Related
TIER 3Resolved
Disinfection byproduct treatment technique failure
When: March 5, 2025 – March 13, 2025Rule: 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: January 1, 2025 – March 31, 2025Rule: 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: January 1, 2025 – March 31, 2025Rule: Stage 2 DBPREnforcement: Resolving — corrective action underway
TIER 2Resolved
Consumer confidence report — content deficiency
When: April 2, 2024 – February 17, 2025Rule: 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
Frequently Asked Questions About WOODSTOCK
Is WOODSTOCK water safe to drink?
WOODSTOCK water receives a grade of B (67/100), which is considered good. Out of 67 contaminants tested, 1 exceed EPA legal limits. 2 contaminant(s) exceed non-enforceable health goals. The water meets federal safety standards.
What contaminants has WOODSTOCK detected?
67 contaminants were tested in WOODSTOCK's water. Notable contaminants include Copper (90th percentile), Lead (90th percentile). 1 exceed EPA legal limits (MCLs). 2 exceed EPA health goals (MCLGs).
Does WOODSTOCK have any EPA violations?
Yes, WOODSTOCK has 10 EPA violation(s) on record, with the most recent in 2025. Violation types include Other, MR, TT. 3 are health-based violations.
How many people does WOODSTOCK serve?
WOODSTOCK serves approximately 25,630 people, Illinois. The system provides water to 1 community: Woodstock.
What type of water does WOODSTOCK provide?
WOODSTOCK sources its water from groundwater. Groundwater is pumped from underground aquifers, which often provides natural filtration. The utility's system ID is IL1110950.
How does WOODSTOCK compare to other utilities in Illinois?
WOODSTOCK scores 67/100 with a grade of B (good). This is an above-average performance for utilities statewide. Visit our Illinois state page for a full comparison of water systems.