WaterVerge

Is Winchester, IL Tap Water Safe to Drink?

Graded B-, with 16 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓

6K residents served 5 water systems PWSID: IL1370030
Overall Score
71.1 / 100
Violations
16 active
Last Updated
May 2026
Source
Purchased surface water
#727 of 891 in Illinois Top 68% nationally
Private
Moderate data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
B-GRADE
Water Quality Grade
71.1/100
waterverge.com
B- 71.1/100

Winchester, IL — Water Quality Report

Winchester's drinking water received a grade of B- (71.1 out of 100), indicating fair water quality. The city's 5 water systems serve approximately 6,065 residents using purchased surface water.

Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program.

The system has 45 violations on record, including 8 health-based violations. 16 remain unresolved.

Data last updated: May 2026 · Source: EPA SDWIS, UCMR 5
Analysis

What to know about Winchester's water

Winchester ranks #727 out of 891 cities in Illinois for water quality, placing it among the lowest-rated in the state.

The city draws from surface water sources, which are more susceptible to seasonal runoff and agricultural contamination, requiring extensive multi-barrier treatment including coagulation, filtration, and disinfection.

The system has seen 10 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.

Quality Breakdown

Water quality score

See methodology →
71.1 out of 100 Grade B-
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
25.1/45
D
Historical violation record including health-based and monitoring violations.
Lead & Copper
20/20
A
Lead at 0.0 ppb (90th percentile).
Contaminants
17/20
B
PFAS + legacy contaminant analysis.
Compliance
5/10
D
Monitoring and reporting compliance with EPA regulations.
Source Risk
4/5
B
Water source: Purchased surface water.
Water Safety

Is Winchester, IL water safe to drink?

Concerns Identified

Winchester's drinking water has significant quality concerns based on EPA testing data. With a grade of B- (71.1/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 5 water systems serve approximately 6,065 residents using surface water (rivers, lakes, or reservoirs).

16
Active Violations
0.0 ppb
Lead (90th %ile)
6 events
Disaster History

Recent water quality updates for Winchester

A timeline of significant water quality events, violations, and data updates.

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Winchester's water quality assessment. Grade: B- (71.1/100).

Violation
1 drinking water violation recorded

Contaminants: Consumer Confidence Rule.

Violation
1 drinking water violation recorded

Contaminants: Public Notice.

Violation
1 drinking water violation recorded

1 health-based. Contaminants: TTHM.

Disaster
SEVERE STORMS AND FLOODING

Federal disaster declaration (FEMA DR-4461). Flood event — may have impacted local water infrastructure.

Disaster
SEVERE STORMS, STRAIGHT-LINE WINDS, AND FLOODING

Federal disaster declaration (FEMA DR-4116). Flood event — may have impacted local water infrastructure.

Key contaminant findings

Based on the most recent EPA sampling data for Winchester's water supply.

Lead Within Limits
Detected: 0.0 ppb Limit: 15 ppb (EPA Action Level)

Well within EPA limits.

Violation history

Winchester's water system has 45 total violations on record, including 8 health-based violations. 16 remain unresolved. 10 violations were issued in the last 5 years.

OtherMCLMRTT
Most recent violations:
Jul 2025 Consumer Confidence Rule Open
Mar 2025 Public Notice Open
Oct 2024 TTHM Resolved
Jul 2024 TTHM Resolved
Apr 2024 TTHM Resolved

Flood & environmental risk

Scott County has experienced 6 federally declared disasters since 1973. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies.

SEVERE STORMS AND FLOODING
Flood FEMA DR-4461
SEVERE STORMS, STRAIGHT-LINE WINDS, AND FLOODING
Flood FEMA DR-4116
HURRICANE KATRINA EVACUATION
Hurricane FEMA DR-3230

Where does Winchester's water come from?

Winchester's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 5 water systems serving approximately 6,065 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment.

What Winchester residents can do

Install a water filter

Recommended: NSF-certified water filter. This addresses the specific contaminants found in Winchester's water.

Request your utility's CCR

Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.

Monitor alerts during storms

Winchester's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.

Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.

Contaminant Alerts

Top contaminants to know

View all ↓
Lead (90th percentile)
Inorganic / Heavy Metal
Safe
0.0 ppb
EPA Action Level: 15 ppb · 0% of limit
Safe Level
Compliance Record

Violation summary

45
Total violations
8
Health-based
16
Active / unresolved
Jul 2025
Most recent violation
Compliance Record

Violations & advisories

45 Total
16 Active
8 Health-based
29 Resolved
1 SNC
Violations by category
Total Coliform Rule
17
Stage 2 Disinfectants and Disinfection Byproducts Rule
8
Lead and Copper Rule
8
Consumer Confidence Rule
5
Stage 1 Disinfectants and Disinfection Byproducts Rule
2
Jul 2025 Active
Consumer Confidence Rule
Other Violation 0
Mar 2025 Active
Public Notice
Other Violation 0
Jul 2023 Active
Consumer Confidence Rule
Other Violation 0
Jul 2023 Active
Consumer Confidence Rule
Other Violation 0
Oct 2022 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Dec 2020 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Jan 2017 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Dec 2013 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Jan 2013 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Jul 2011 Active
Consumer Confidence Rule
Other Violation 0
Jan 2011 Active
Lead and Copper Rule
Treatment Technique
Health-Based Health 0
Jul 2005 Active
Consumer Confidence Rule
Other Violation 0
Oct 2004 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Jul 1995 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Active
Compliance Violation
Monitoring 0
Active
Compliance Violation
Monitoring 0
Oct 2024 Resolved
TTHM
Max Contaminant Level
Health-Based Health Resolved Dec 2024
Jul 2024 Resolved
TTHM
Max Contaminant Level
Health-Based Health Resolved Sep 2024
Apr 2024 Resolved
TTHM
Max Contaminant Level
Health-Based Health Resolved Jun 2024
Jan 2024 Resolved
TTHM
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2024
Showing 20 of 45 violations
Environmental Risk

Flood & disaster history

6
Declared disasters
Sep 2019
Most recent
Flood
Most common type

Scott County has experienced 6 federally declared disasters since 1973. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.

Sep 2019
SEVERE STORMS AND FLOODING
Flood FEMA #4461
May 2013
SEVERE STORMS, STRAIGHT-LINE WINDS, AND FLOODING
Flood FEMA #4116
Sep 2005
HURRICANE KATRINA EVACUATION
Hurricane FEMA #3230
Jul 1993
SEVERE STORMS & FLOODING
Flood FEMA #997
Apr 1979
SEVERE STORMS & FLOODING
Flood FEMA #583
Apr 1973
SEVERE STORMS & FLOODING
Flood FEMA #373

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 0.0 15 ppb Inorganic Safe
Data source: EPA SDWIS, UCMR 5, local utility CCR.

Lead level trend (90th percentile)

EPA action level: 15 ppb
Lead has decreased by 8.0 ppb from 1993 (8.0 ppb) to 2027 (0.0 ppb).
Infrastructure

Water source & infrastructure

Primary Source
Purchased Surface Water
Operator
Private
Population Served
6,065
Water Systems
5
Source breakdown
Purchased Groundwater
3
Purchased Surface Water
1
Groundwater
1
Water Source

Where Winchester's water comes from

Purchased Surface Water

Winchester's drinking water comes primarily from surface water sources such as rivers, lakes, or reservoirs.

Surface water systems require multi-stage treatment including coagulation, sedimentation, filtration, and disinfection to meet EPA Safe Drinking Water Act standards.

These sources can be impacted by seasonal changes, stormwater runoff, upstream agriculture, and industrial discharge.

The system is operated by private ownership and serves approximately 6,065 people through 5 water systems.

Infrastructure

Water systems serving Winchester

System Name PWSID Population Source
SMG WATER COOP IL1370030 3,110 SWP
WINCHESTER IL1710350 1,589 GW
EXETER-MERRITT WATER COOP IL1710010 820 GWP
SCOTT COUNTY RURAL WATER CO-OP IL1710020 493 GWP
WEST MORGAN WATER CORPORATION IL1370010 53 GWP
Regional Comparison

How Winchester compares

Full Illinois rankings →

Winchester's score of 71.1/100 is above the average of 56/100 among major Illinois cities. It outscores 7 of 10 nearby cities.

Winchester (this city)
71.1
Chicago
35.2
Aurora
45.5
Joliet
38.5
Naperville
81.2
Champaign
91.9
Illinois avg
56
City Profile

About Winchester, IL

Economic Profile
$51,667
Median Income
$95,113
Median Home Value
$575/mo
Median Rent
4.6%
Unemployment
Community
39.7
Median Age
527
People / sq mi
21.6%
College Educated
67.8%
Homeownership
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Frequently asked questions

Is Winchester, IL tap water safe to drink?

Winchester's water quality earned a grade of B- (71.1/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #727 out of 891 cities tested in Illinois.

What contaminants are in Winchester's water?

Lead was measured at 0.0 ppb (90th percentile). 45 violations are on record.

How is Winchester's water quality grade calculated?

The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.

Do I need a water filter in Winchester?

Based on current data, basic filtration should suffice for additional peace of mind.

Where does Winchester's water come from?

Winchester's water is sourced from Purchased surface water. The city has 5 water systems serving approximately 6,065 residents.

What health violations has Winchester's water system had?

Winchester has 8 health-based violations on record. The most recent violation was recorded in July 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 16 violations remain unresolved.

How does Winchester's water compare to other cities?

Winchester ranks #727 out of 891 cities in Illinois (better than 18% of state cities) and #10610 out of 15744 cities nationally (33th percentile). The grade of B- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.