Marion County, Ohio
8 ZIP codes · Avg score 55/100 · Grade C · Updated 2026-06-03
Safe water is the norm for most of Marion County's 8 ZIP codes — but a notable subset have documented violations that push the grade to the middle tier.
How Marion County Compares
How Marion County Compares
Marion County scores 5 points below the Ohio state average (60/100) and 13 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Marion County, Ohio
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 15.8 (asthma 10.9%, diabetes 14.8%)
Estimated additional annual cost per homeowner: $1,336, driven primarily by sea_level
Infrastructure: 0.374% avg pipe failure probability, 63% of ZIPs at high risk
80.6% 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: $1,336
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
24,788 housing units in Marion 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 Marion County
Remediation costs are relatively manageable for most homeowners in Marion 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 Marion County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water Systems with Most Violations
Top 4 systems in Marion County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Aqua Ohio - Marion | 46,317 | 12 |
| 2 | Aqua Ohio - Tiffin | 20,035 | 12 |
| 3 | Aqua Ohio - La Rue Village | 800 | 12 |
| 4 | Del-Company Water Company, Inc. | 150,000 | 3 |
All ZIP Codes in Marion County
8 ZIP codes tracked in Marion County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 43301 | Marion | 62 | C | 3 | — |
| 2 | 43306 | Marion | 62 | C | 3 | — |
| 3 | 43307 | Marion | 62 | C | 3 | — |
| 4 | 43302 | Marion | 61 | C | 3 | $140K |
| 5 | 43314 | Caledonia | 53 | D | 0 | $180K |
| 6 | 43322 | Green Camp | 53 | D | 0 | $119K |
| 7 | 43341 | New Bloomington | 45 | D | 0 | $163K |
| 8 | 43337 | Morral | 40 | D | 0 | $154K |
Recommended Buyer Guides for Marion County
Filtered against federal data, fitted to local risks.
- Best Lead Paint Test Kits — 80.6% of homes built before 1978
- Best Radon Test Kits — EPA Radon Zone 1 (highest risk) dominant in county
Deep Dive Reports
Detailed analysis for Marion County, Ohio
Overview
Marion County in Ohio covers 8 ZIP codes with an average Home Safety Score of C (55/100).
4 of 8 ZIP codes have recorded EPA violations. All violations are monitoring/reporting type.
← Back to Ohio 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.