Mercer County, Missouri
4 ZIP codes · Avg score 72/100 · Grade B · Updated 2026-06-03
Covering 4 ZIP codes, Mercer County earns a high grade for tap water — most systems report zero health-based violations, and the overall compliance rate comfortably exceeds federal benchmarks.
How Mercer County Compares
How Mercer County Compares
Mercer County scores 3 points above the Missouri state average (69/100) and 4 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
Key Risk Factors
Health risk index: 16.2 (asthma 10.7%, diabetes 15.1%)
Estimated additional annual cost per homeowner: $375, driven primarily by energy_code_gap
Infrastructure: 0.42% avg pipe failure probability, 75% of ZIPs at high risk
69.5% of homes built before 1978 (lead paint era)
Violation History (2024–2025)
→ Stable trendEPA violation counts by year across Mercer County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 4 violations. Past 5 years: 7 total (7 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: $375
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
2,153 housing units in Mercer 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 Mercer County
Remediation costs are relatively manageable for most homeowners in Mercer 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 Mercer 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 Mercer County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Mercer County Pwsd 1 | 3,200 | 19 |
| 2 | Mercer Public Water System | 318 | 14 |
| 3 | Harrison County Pwsd 2 | 3,740 | 3 |
| 4 | Cainsville Public Water System | 290 | 3 |
| 5 | Princeton Public Water System | 1,283 | 2 |
6 total water systems serve Mercer County.
All ZIP Codes in Mercer County
4 ZIP codes tracked in Mercer County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 64632 | Cainsville | 82 | B | 3 | $79K |
| 2 | 64673 | Princeton | 82 | B | 2 | $91K |
| 3 | 64661 | Mercer | 69 | C | 14 (5 health) | $80K |
| 4 | 64672 | Powersville | 53 | D | 0 | — |
Recommended Buyer Guides for Mercer 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 Lead Paint Test Kits — 69.5% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
Overview
Mercer County in Missouri covers 4 ZIP codes with an average Home Safety Score of B (72/100).
3 of 4 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.