Marion County, Missouri
6 ZIP codes · Avg score 64/100 · Grade C · Updated 2026-06-03
Unlike top-rated counties, Marion County's 6 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 Marion County Compares
How Marion County Compares
Marion County scores 5 points below the Missouri state average (69/100) and 4 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Marion County, Missouri
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 15.1 (asthma 10.6%, diabetes 13.4%)
Estimated additional annual cost per homeowner: $1,228, driven primarily by flood
Infrastructure: 0.358% avg pipe failure probability, 17% of ZIPs at high risk
58.8% of homes built before 1978 (lead paint era)
Violation History (2022–2025)
→ Stable trendEPA violation counts by year across Marion County water systems. Health-based shown in red, total in blue.
Peak year: 2022 with 9 violations. Past 5 years: 16 total (16 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: $1,228
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
12,910 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 5 systems in Marion County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | MARION COUNTY PWSD 1 | 4,900 | 6 |
| 2 | Hannibal Public Water System | 17,108 | 5 |
| 3 | Ralls County Pwsd 1 | 7,662 | 5 |
| 4 | Cannon Pwsd 1 | 6,482 | 5 |
| 5 | NEW LONDON PWS | 975 | 5 |
8 total water systems serve Marion County.
All ZIP Codes in Marion County
6 ZIP codes tracked in Marion County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 63463 | Philadelphia | 83 | B | 1 | $130K |
| 2 | 63461 | Palmyra | 73 | B | 0 | $177K |
| 3 | 63439 | Emden | 63 | C | 0 | $80K |
| 4 | 63401 | Hannibal | 59 | C | 5 (5 health) | $144K |
| 5 | 63467 | Saverton | 53 | D | 0 | — |
| 6 | 63471 | Taylor | 50 | D | 0 | $244K |
Recommended Buyer Guides for Marion County
Eight risk categories drive the selection — PFAS exceedance, lead above EPA action level, pre-1978 housing share, EPA Radon Zone 1, flood-top-risk, wildfire-top-risk, multi-contaminant load, and a baseline fallback — and each category maps to a specific buyer-guide track that surfaces when the county data hits its threshold for that hazard signal.
- Best Lead Paint Test Kits — 58.8% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
- 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 Marion County, Missouri
Overview
Marion County in Missouri covers 6 ZIP codes with an average Home Safety Score of C (64/100).
2 of 6 ZIP codes have recorded EPA violations. 5 health-based violations have been documented.
← Back to Missouri 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.