St. Louis County, Missouri
56 ZIP codes · Avg score 81/100 · Grade B · Updated
ZipCheckup grade for St. Louis County: B.
This ZIP looks solid, with a few items worth a quick check.
Unlike many counties its size, St. Louis County keeps violation rates low - all 56 ZIP codes score at or above the state average for tap water safety, with no systemic concerns flagged in the current data set.
How St. Louis County Compares
How St. Louis County Compares
St. Louis County scores 9 points above the Missouri state average (72/100) and 8 points above the national average (73/100).
Data: ZipCheckup Home Safety Score model 4.0.0; EPA SDWIS, UCMR 5, EPA radon zones, EPA AirData Last verified:
ZIP Code Risk Map
Water Quality Map: St. Louis County, Missouri
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 12.5 (asthma 10.6%, diabetes 11.5%)
Estimated additional annual cost per homeowner: $2,392, driven primarily by flood
74% of homes built before 1978 (lead paint era)
Violation History (2022–2025)
↓ Improving trendEPA violation counts by year across St. Louis County water systems. Health-based shown in red, total in blue.
Peak year: 2023 with 34 violations. Past 5 years: 57 total (57 health-based). Health-based violations are declining versus the prior 2-year window.
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
Modeled area-level indicator, not a failure probability. Sources: Census ACS housing age, EPA DWINS infrastructure needs, EPA SDWIS violations, and EPA lead indicators.
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $2,392
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
474,839 housing units in St. Louis 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 St. Louis County
Remediation costs are relatively manageable for most homeowners in St. Louis 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 St. Louis County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water systems serving St. Louis County
8 community water systems serving St. Louis County.
- B
- B
- B
- B
- B
- B
Show all 8 water systems
- B
- B
17 total water systems serve St. Louis County.
Systems with the most violations in St. Louis County
5 water systems with recorded EPA violations.
- B
- B
- B
- B
All ZIP Codes in St. Louis County
56 ZIP codes tracked in St. Louis County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 63011 | Ballwin | 83 | B | 1 (1 health) | $374K |
| 2 | 63017 | Chesterfield | 83 | B | 0 | $452K |
| 3 | 63031 | Florissant | 83 | B | 0 | $145K |
| 4 | 63033 | Florissant | 83 | B | 0 | $157K |
| 5 | 63034 | Florissant | 83 | B | 0 | $234K |
| 6 | 63040 | Grover | 83 | B | 1 (1 health) | $409K |
| 7 | 63042 | Hazelwood | 83 | B | 0 | $139K |
| 8 | 63043 | Maryland Heights | 83 | B | 0 | $216K |
| 9 | 63044 | Bridgeton | 83 | B | 0 | $232K |
| 10 | 63045 | Earth City | 83 | B | 0 | — |
| 11 | 63074 | Saint Ann | 83 | B | 0 | $120K |
| 12 | 63088 | Valley Park | 83 | B | 1 (1 health) | $232K |
| 13 | 63114 | Saint Louis | 83 | B | 0 | $110K |
| 14 | 63122 | Saint Louis | 83 | B | 0 | $450K |
| 15 | 63124 | Saint Louis | 83 | B | 0 | $967K |
| 16 | 63126 | Saint Louis | 83 | B | 0 | $287K |
| 17 | 63127 | Saint Louis | 83 | B | 0 | $594K |
| 18 | 63128 | Saint Louis | 83 | B | 0 | $320K |
| 19 | 63129 | Saint Louis | 83 | B | 0 | $279K |
| 20 | 63131 | Saint Louis | 83 | B | 0 | $734K |
| 21 | 63132 | Saint Louis | 83 | B | 0 | $404K |
| 22 | 63134 | Saint Louis | 83 | B | 0 | $92K |
| 23 | 63135 | Saint Louis | 83 | B | 0 | $96K |
| 24 | 63140 | Saint Louis | 83 | B | 0 | $84K |
| 25 | 63144 | Saint Louis | 83 | B | 0 | $279K |
| 26 | 63146 | Saint Louis | 83 | B | 0 | $284K |
| 27 | 63005 | Chesterfield | 82 | B | 3 | $671K |
| 28 | 63038 | Glencoe | 82 | B | 2 (1 health) | $538K |
| 29 | 63021 | Ballwin | 81 | B | 4 (2 health) | $324K |
| 30 | 63025 | Eureka | 81 | B | 6 | $364K |
| 31 | 63026 | Fenton | 81 | B | 5 (1 health) | $282K |
| 32 | 63103 | Saint Louis | 79 | B | 8 | $205K |
| 33 | 63105 | Saint Louis | 79 | B | 8 | $736K |
| 34 | 63117 | Saint Louis | 79 | B | 8 | $330K |
| 35 | 63119 | Saint Louis | 79 | B | 8 | $331K |
| 36 | 63120 | Saint Louis | 79 | B | 8 | $52K |
| 37 | 63121 | Saint Louis | 79 | B | 8 | $94K |
| 38 | 63123 | Saint Louis | 79 | B | 8 | $205K |
| 39 | 63125 | Saint Louis | 79 | B | 8 | $166K |
| 40 | 63130 | Saint Louis | 79 | B | 8 | $286K |
| 41 | 63133 | Saint Louis | 79 | B | 8 | $59K |
| 42 | 63136 | Saint Louis | 79 | B | 8 | $77K |
| 43 | 63137 | Saint Louis | 79 | B | 8 | $79K |
| 44 | 63138 | Saint Louis | 79 | B | 8 | $125K |
| 45 | 63139 | Saint Louis | 79 | B | 8 | $199K |
| 46 | 63049 | High Ridge | 76 | B | 49 (1 health) | $209K |
| 47 | 63006 | Chesterfield | — | — | — | |
| 48 | 63022 | Ballwin | — | — | — | |
| 49 | 63024 | Ballwin | — | — | — | |
| 50 | 63032 | Florissant | — | — | — | |
| 51 | 63055 | Labadie | — | — | 7 | $254K |
| 52 | 63099 | Fenton | — | — | — | |
| 53 | 63145 | Saint Louis | — | — | — | |
| 54 | 63151 | Saint Louis | — | — | — | |
| 55 | 63166 | Saint Louis | — | — | — | |
| 56 | 63167 | Saint Louis | — | — | — |
Recommended Buyer Guides for St. Louis County
Filtered against EPA monitoring data and CDC lead-exposure guidance, the guides below skip the generic catalog and connect directly to the contaminants and hazards on file here.
- Best Water Filters for PFAS — PFAS detected in 1 ZIP code
- Best Lead Paint Test Kits — 74% 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 St. Louis County, Missouri
Overview
St. Louis County in Missouri covers 56 tracked ZIP records with an average Home Safety Score of B (81/100) across 46 scored records.
24 of 47 ZIP codes with a reported violation count in the available EPA record have recorded EPA violations. 2 health-based violations appear in the available health breakdown.
← Back to Missouri Home Safety Profile
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- PFAS screening: EPA UCMR 5
- Radon zones: EPA Map of Radon Zones
- Air quality: EPA AirData annual AQI
- Home values: U.S. Census Bureau ACS (median estimates by ZCTA)
Reporting periods vary by source. Missing data is shown as unavailable, not as zero.