B67/100
DEERFIELD — Water Quality Report 2026
Serving 19,196 people · Illinois
Water Source
Purchased Surface Water
County
—
System ID
IL0974340
Violations
14
Contaminant Test Results
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Lead (90th percentile) | 0.009 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
5
Violations (last 5yr)
1
Unresolved
0
Health-Related
TIER 3Unresolved
Surface water treatment technique failure
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 3Resolved
Surface water treatment technique failure
When: July 10, 2023 – July 1, 2024Enforcement: Resolving — corrective action underway
TIER 3Resolved
Surface water treatment technique failure
When: July 1, 2022 – July 1, 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
Frequently Asked Questions About DEERFIELD
Is DEERFIELD water safe to drink?
DEERFIELD water receives a grade of B (67/100), which is considered good. Out of 69 contaminants tested, none exceed EPA legal limits. 1 contaminant(s) exceed non-enforceable health goals. The water meets federal safety standards.
What contaminants has DEERFIELD detected?
69 contaminants were tested in DEERFIELD's water. Notable contaminants include Lead (90th percentile). No contaminants exceed EPA legal limits. 1 exceed EPA health goals (MCLGs).
Does DEERFIELD have any EPA violations?
Yes, DEERFIELD has 14 EPA violation(s) on record, with the most recent in 2025. Violation types include Other, MR, MCL. 4 are health-based violations.
How many people does DEERFIELD serve?
DEERFIELD serves approximately 19,196 people, Illinois. The system provides water to 1 community: Deerfield.
What type of water does DEERFIELD provide?
DEERFIELD sources its water from purchased surface water. Surface water comes from rivers, lakes, or reservoirs and typically requires more extensive treatment. The utility's system ID is IL0974340.
How does DEERFIELD compare to other utilities in Illinois?
DEERFIELD 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.