Monroe County, Illinois
5 ZIP codes · Avg score 68/100 · Grade C · Updated 2026-06-03
Unlike top-rated counties, Monroe County's 5 ZIP codes carry a fair number of documented violations — chlorine compliance and disinfection byproduct limits are the categories most often cited in recent data.
How Monroe County Compares
How Monroe County Compares
Monroe County scores 7 points above the Illinois state average (61/100) and 0 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Monroe County, Illinois
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 12.3 (asthma 9.9%, diabetes 10.1%)
Estimated additional annual cost per homeowner: $1,874, driven primarily by flood
Infrastructure: 0.35% avg pipe failure probability, 20% of ZIPs at high risk
48% of homes built before 1978 (lead paint era)
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: $1,874
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
14,048 housing units in Monroe 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 Monroe County
Remediation costs are relatively manageable for most homeowners in Monroe County, representing a small fraction of property value.
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 Monroe 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 Monroe County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Waterloo | 10,190 | 11 |
| 2 | Valmeyer | 1,263 | 9 |
| 3 | Il American-east St Louis | 131,368 | 7 |
| 4 | Millstadt | 4,071 | 7 |
| 5 | Hecker | 429 | 7 |
11 total water systems serve Monroe County.
All ZIP Codes in Monroe County
5 ZIP codes tracked in Monroe County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 62248 | Hecker | 78 | B | 7 (1 health) | $154K |
| 2 | 62256 | Maeystown | 75 | B | 0 | $154K |
| 3 | 62298 | Waterloo | 74 | B | 5 | $263K |
| 4 | 62236 | Columbia | 61 | C | 2 | $300K |
| 5 | 62295 | Valmeyer | 54 | D | 4 (1 health) | $197K |
Recommended Buyer Guides for Monroe County
Designed to find the guide that fits the county, not the other way around — the system reads EPA detections, FEMA hazard layers, and CDC lead-exposure markers, then outputs the categories that resolve those specific risks for households here, with NSF-certified products surfaced when the matching contaminant appears in the local monitoring data.
- Best Sump Pumps — Flood is the top compound risk factor
- Best Mold Test Kits — Flood-driven moisture and mold risk
Deep Dive Reports
Detailed analysis for Monroe County, Illinois
Overview
Monroe County in Illinois covers 5 ZIP codes with an average Home Safety Score of C (68/100).
4 of 5 ZIP codes have recorded EPA violations. 2 health-based violations 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.