Warren County, Missouri
4 ZIP codes · Avg score 72/100 · Grade B · Updated 2026-06-03
Recent water monitoring in Warren County shows 4 ZIP codes with consistently safe results.
How Warren County Compares
How Warren County Compares
Warren 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: 13.7 (asthma 10.4%, diabetes 11.8%)
Estimated additional annual cost per homeowner: $518, driven primarily by flood
Infrastructure: 0.277% avg pipe failure probability
37.7% of homes built before 1978 (lead paint era)
Violation History (2023–2024)
→ Stable trendEPA violation counts by year across Warren County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 3 violations. Past 5 years: 4 total (4 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: $518
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
8,573 housing units in Warren 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 Warren County
Remediation costs are relatively manageable for most homeowners in Warren 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 Warren 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 Warren County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Montgomery Company Pwsd 1 | 3,850 | 13 |
| 2 | St Charles County Pwsd 2 Warren | 1,192 | 13 |
| 3 | Truesdale Public Water System | 853 | 10 |
| 4 | Warrenton Public Water System | 8,208 | 10 |
| 5 | St Charles Company Pwsd #2 Wright City | 3,550 | 10 |
16 total water systems serve Warren County.
All ZIP Codes in Warren County
4 ZIP codes tracked in Warren County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 63380 | Truesdale | 83 | B | 0 | $200K |
| 2 | 63390 | Wright City | 72 | B | 10 | $245K |
| 3 | 63357 | Marthasville | 70 | B | 3 | $243K |
| 4 | 63378 | Treloar | 63 | C | 0 | — |
Recommended Buyer Guides for Warren County
Where county records show a lead exceedance or pre-1978 housing concentration, lead-specific filters and test kits move toward the top of the list.
- Best Sump Pumps — Flood is the top compound risk factor
- Best Mold Test Kits — Flood-driven moisture and mold risk
Overview
Warren County in Missouri covers 4 ZIP codes with an average Home Safety Score of B (72/100).
2 of 4 ZIP codes have recorded EPA violations. All violations are monitoring/reporting type.
← 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.