Coles County, Illinois
7 ZIP codes · Avg score 54/100 · Grade D · Updated 2026-06-03
Monitoring across Coles County's 7 ZIP codes reveals a persistent pattern of below-average water quality — multiple areas carry documented health violations, and the data has shown little improvement over recent reporting cycles.
How Coles County Compares
How Coles County Compares
Coles County scores 7 points below the Illinois state average (61/100) and 14 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Coles County, Illinois
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 13.4 (asthma 10.7%, diabetes 11.5%)
Estimated additional annual cost per homeowner: $1,301, driven primarily by energy_code_gap
Infrastructure: 0.446% avg pipe failure probability, 86% of ZIPs at high risk
72.4% of homes built before 1978 (lead paint era)
Violation History (2021–2024)
→ Stable trendEPA violation counts by year across Coles County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 2 violations. Past 5 years: 3 total (3 health-based).
Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.
County Health Indicators vs National Average
Black markers indicate national averages. Source: CDC PLACES, Census ACS.
Infrastructure Overview
Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $1,301
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
22,820 housing units in Coles County
Source: U.S. Census Bureau ACS B25034 (Year Structure Built).
Water Safety Affordability
How much it costs to fix water issues relative to home values in Coles County
Water safety remediation is a moderate expense relative to home values. Most homeowners can address issues through staged improvements over time.
Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.
Health Outcomes vs National Average
CDC PLACES data for Coles County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water Systems with Most Violations
Top 5 systems in Coles County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Mattoon | 19,500 | 14 |
| 2 | Charleston | 17,286 | 11 |
| 3 | Eastern Illinois University | 5,500 | 11 |
| 4 | Embarras Area Water District | 3,750 | 11 |
| 5 | Ashmore | 637 | 9 |
12 total water systems serve Coles County.
All ZIP Codes in Coles County
7 ZIP codes tracked in Coles County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 61920 | Charleston | 61 | C | 11 (1 health) | $145K |
| 2 | 61938 | Mattoon | 59 | C | 3 | $109K |
| 3 | 61943 | Oakland | 54 | D | 7 | $105K |
| 4 | 62440 | Lerna | 53 | D | 0 | $142K |
| 5 | 62469 | Trilla | 53 | D | 0 | $99K |
| 6 | 61912 | Ashmore | 52 | D | 9 | $110K |
| 7 | 61931 | Humboldt | 45 | D | 0 | $126K |
Recommended Buyer Guides for Coles County
Retailer arrangements don't shape what appears here — the selection logic is independent, filtered against EPA detections and the federal hazard data on file for this county.
- Best Water Filters for Lead — Lead above EPA action level in 1 ZIP code
- Best Lead Paint Test Kits — 72.4% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
- Best Radon Test Kits — EPA Radon Zone 1 (highest risk) dominant in county
Deep Dive Reports
Detailed analysis for Coles County, Illinois
Overview
Coles County in Illinois covers 7 ZIP codes with an average Home Safety Score of D (54/100).
4 of 7 ZIP codes have recorded EPA violations. 1 health-based violation have been documented.
← Back to Illinois water quality report
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Home values: U.S. Census Bureau ACS (median estimates by ZCTA)
Updated daily.
What You Can Do
Coles County has a grade of D. Here are steps to protect your household.
Test your tap water
Order a certified lab test kit ($20-$50) to check for lead, bacteria, and other contaminants specific to your ZIP code.
Consider a certified water filter
NSF-certified filters can remove most common contaminants. Match the filter to your test results for best protection. Try our filter matcher
Contact your water utility
Request the latest Consumer Confidence Report (CCR) from your water provider. It details exactly what was found in your water supply.
Check for lead in your home
72.4% of homes in this county were built before 1978. Older plumbing and solder can leach lead into drinking water, especially in the morning.