TapSafetyReport
B61/100

MCHENRY — Water Quality Report 2026

Serving 22,335 people · Illinois

Water Source
Groundwater
County
—
System ID
IL1110600
Violations
28

Contaminant Test Results

1 contaminant above EPA health goals
ContaminantDetectedLimit (MCL)Status
Lead (90th percentile)
0.006 mg/L0.015 mg/LAbove Goal

EPA Violation History

23

Violations (last 5yr)

1

Unresolved

0

Health-Related

TIER 3Unresolved

Failed to issue ongoing public notification

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

When: July 1, 2025Rule: Ground Water RuleEnforcement: Informal — resolved cooperativelyVerify on EPA.gov
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 29, 2024Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

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

When: January 1, 2023 – December 31, 2023Rule: Revised Total Coliform RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

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

When: January 1, 2023 – December 31, 2023Rule: Revised Total Coliform RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

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

When: January 1, 2023 – December 31, 2023Rule: Revised Total Coliform RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

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

When: January 1, 2023 – December 31, 2023Rule: Revised Total Coliform RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

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

When: January 1, 2023 – December 31, 2023Rule: Revised Total Coliform RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

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

When: January 1, 2023 – December 31, 2023Rule: Revised Total Coliform RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

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

When: January 1, 2023 – December 31, 2023Rule: Revised Total Coliform RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

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

When: January 1, 2023 – December 31, 2023Rule: Revised Total Coliform RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

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

When: January 1, 2023 – December 31, 2023Rule: Revised Total Coliform RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

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

When: January 1, 2023 – December 31, 2023Rule: Revised Total Coliform RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

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

When: January 1, 2023 – December 31, 2023Rule: Revised Total Coliform RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

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

When: January 1, 2023 – December 31, 2023Rule: Revised Total Coliform RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

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

When: January 1, 2023 – December 31, 2023Rule: Revised Total Coliform RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

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

When: January 1, 2023 – December 31, 2023Rule: Revised Total Coliform RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

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

When: January 1, 2023 – December 31, 2023Rule: Revised Total Coliform RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

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

When: January 1, 2023 – December 31, 2023Rule: Revised Total Coliform RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

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

When: January 1, 2023 – December 31, 2023Rule: Revised Total Coliform RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

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

When: January 1, 2023 – December 31, 2023Rule: Revised Total Coliform RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

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

When: January 1, 2023 – December 31, 2023Rule: Revised Total Coliform RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

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

When: January 1, 2023 – December 31, 2023Rule: Revised Total Coliform RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

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

When: January 1, 2023 – December 31, 2023Rule: Revised Total Coliform 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 MCHENRY

Is MCHENRY water safe to drink?

MCHENRY water receives a grade of B (61/100), which is considered good. Out of 66 contaminants tested, none exceed EPA legal limits. 1 contaminant(s) exceed non-enforceable health goals. The water meets federal safety standards.

What contaminants has MCHENRY detected?

66 contaminants were tested in MCHENRY's water. Notable contaminants include Lead (90th percentile). No contaminants exceed EPA legal limits. 1 exceed EPA health goals (MCLGs).

Does MCHENRY have any EPA violations?

Yes, MCHENRY has 28 EPA violation(s) on record, with the most recent in 2025. Violation types include MR, MCL, TT. 2 are health-based violations.

How many people does MCHENRY serve?

MCHENRY serves approximately 22,335 people, Illinois. The system provides water to 1 community: Mchenry.

What type of water does MCHENRY provide?

MCHENRY sources its water from groundwater. Groundwater is pumped from underground aquifers, which often provides natural filtration. The utility's system ID is IL1110600.

How does MCHENRY compare to other utilities in Illinois?

MCHENRY scores 61/100 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.

Cities Served

Mchenry