TapSafetyReport
D35/100

WINTHROP HARBOR — Water Quality Report 2026

Serving 6,565 people · Illinois

Water Source
Purchased Surface Water
County
—
System ID
IL0971950
Violations
37

Contaminant Test Results

EPA Violation History

17

Violations (last 5yr)

6

Unresolved

0

Health-Related

TIER 3Unresolved

Surface water treatment technique failure

When: July 1, 2025Enforcement: Informal — resolved cooperativelyVerify on EPA.gov
TIER 3Resolved

Disinfection byproduct treatment technique failure

When: January 12, 2025 – January 22, 2025Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Disinfection byproduct treatment technique failure

When: October 11, 2024 – November 15, 2024Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Disinfection byproduct treatment technique failure

When: October 11, 2024 – November 15, 2024Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 3Unresolved

Surface water treatment technique failure

When: July 1, 2024Enforcement: Informal — resolved cooperativelyVerify on EPA.gov
TIER 3Resolved

Surface water treatment technique failure

When: July 1, 2024 – July 17, 2024Enforcement: 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 to issue ongoing public notification

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: October 1, 2023 – February 23, 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: July 1, 2023 – September 30, 2023Rule: Stage 2 DBPREnforcement: Resolving — corrective action underway
TIER 3Unresolved

Surface water treatment technique failure

When: July 1, 2023Enforcement: Informal — resolved cooperativelyVerify on EPA.gov
TIER 3Resolved

Surface water treatment technique failure

When: July 1, 2023 – August 30, 2023Enforcement: 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: July 1, 2023 – September 30, 2023Rule: Stage 2 DBPREnforcement: Resolving — corrective action underway
TIER 3Unresolved

Monitoring / Reporting Violation

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: December 30, 2022Rule: Ground Water RuleEnforcement: Informal — resolved cooperativelyVerify on EPA.gov
TIER 3Unresolved

Monitoring / Reporting Violation

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: December 30, 2021Rule: Ground Water RuleEnforcement: Informal — resolved cooperativelyVerify on EPA.gov
TIER 3Unresolved

Disinfection byproduct treatment technique failure

When: October 21, 2021Rule: Ground Water RuleEnforcement: Informal — resolved cooperativelyVerify on EPA.gov
TIER 3Resolved

Surface water treatment technique failure

When: July 1, 2021 – August 16, 2021Enforcement: 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 WINTHROP HARBOR

Is WINTHROP HARBOR water safe to drink?

WINTHROP HARBOR water receives a grade of D (35/100), which is considered poor. 0 contaminant(s) exceed EPA legal limits and 37 violation(s) are on record. Customers may want to consider using a water filter.

What contaminants has WINTHROP HARBOR detected?

31 contaminants were tested in WINTHROP HARBOR's water. No contaminants exceed EPA legal limits or health goals, indicating good water quality management.

Does WINTHROP HARBOR have any EPA violations?

Yes, WINTHROP HARBOR has 37 EPA violation(s) on record, with the most recent in 2025. Violation types include Other, MR, MCL. 7 are health-based violations.

How many people does WINTHROP HARBOR serve?

WINTHROP HARBOR serves approximately 6,565 people, Illinois. The system provides water to 1 community: Winthrop Harbor.

What type of water does WINTHROP HARBOR provide?

WINTHROP HARBOR 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 IL0971950.

How does WINTHROP HARBOR compare to other utilities in Illinois?

WINTHROP HARBOR scores 35/100 with a grade of D (poor). This score suggests significant water quality concerns relative to other utilities. Visit our Illinois state page for a full comparison of water systems.

Cities Served

Winthrop Harbor