Jefferson County, Missouri
94 ZIP codes · Avg score 55/100 · Grade C · Updated 2026-06-03
For most households in Jefferson County, the 94 tracked ZIP codes show adequate but uneven water quality.
How Jefferson County Compares
How Jefferson County Compares
Jefferson County scores 14 points below the Missouri state average (69/100) and 13 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Jefferson County, Missouri
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 13.2 (asthma 11%, diabetes 12.2%)
Estimated additional annual cost per homeowner: $1,735, driven primarily by flood
Infrastructure: 0.409% avg pipe failure probability, 61% of ZIPs at high risk
74.3% of homes built before 1978 (lead paint era)
Violation History (2022–2025)
↓ Improving trendEPA violation counts by year across Jefferson County water systems. Health-based shown in red, total in blue.
Peak year: 2023 with 70 violations. Past 5 years: 85 total (85 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
Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $1,735
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
548,880 housing units in Jefferson 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 Jefferson County
Remediation costs are relatively manageable for most homeowners in Jefferson 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 Jefferson 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 Jefferson County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Jefferson County Pwsd 6 | 7,500 | 25 |
| 2 | Hillsboro Public Water System | 3,000 | 25 |
| 3 | Jefferson Company Pwsd 8 | 4,733 | 24 |
| 4 | Jefferson County Pwsd 7 | 6,100 | 21 |
| 5 | Raintree Plantation | 2,200 | 21 |
42 total water systems serve Jefferson County.
All ZIP Codes in Jefferson County
94 ZIP codes tracked in Jefferson County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 63070 | Pevely | 74 | B | 5 | $209K |
| 2 | 63012 | Barnhart | 73 | B | 0 | $229K |
| 3 | 63028 | Festus | 73 | B | 1 | $222K |
| 4 | 63048 | Herculaneum | 73 | B | 0 | $216K |
| 5 | 63020 | De Soto | 72 | B | 3 | $173K |
| 6 | 63050 | Hillsboro | 72 | B | 6 (1 health) | $256K |
| 7 | 63052 | Imperial | 70 | B | 3 | $259K |
| 8 | 63051 | House Springs | 68 | C | 1 | $186K |
| 9 | 63023 | Dittmer | 66 | C | 2 | $220K |
| 10 | 63019 | Crystal City | 65 | C | 3 (3 health) | $170K |
| 11 | 63016 | Cedar Hill | 63 | C | 15 (2 health) | $207K |
| 12 | 63030 | Fletcher | 63 | C | 0 | $192K |
| 13 | 63032 | Florissant | 63 | C | 0 | — |
| 14 | 63040 | Grover | 63 | C | 0 | $409K |
| 15 | 63053 | Kimmswick | 63 | C | 0 | $217K |
| 16 | 63103 | Saint Louis | 63 | C | 0 | $205K |
| 17 | 63104 | Saint Louis | 63 | C | 0 | $250K |
| 18 | 63106 | Saint Louis | 63 | C | 0 | $187K |
| 19 | 63110 | Saint Louis | 63 | C | 0 | $315K |
| 20 | 63113 | Saint Louis | 63 | C | 0 | $76K |
| 21 | 63115 | Saint Louis | 63 | C | 0 | $62K |
| 22 | 63140 | Saint Louis | 63 | C | 0 | $84K |
| 23 | 63145 | Saint Louis | 63 | C | 0 | — |
| 24 | 63157 | Saint Louis | 63 | C | 0 | — |
| 25 | 63166 | Saint Louis | 63 | C | 0 | — |
| 26 | 63177 | Saint Louis | 63 | C | 0 | — |
| 27 | 63626 | Blackwell | 63 | C | 0 | $118K |
| 28 | 63010 | Arnold | 55 | C | 1 | $214K |
| 29 | 63066 | Morse Mill | 55 | C | 0 | — |
| 30 | 63101 | Saint Louis | 55 | C | 0 | $228K |
| 31 | 63102 | Saint Louis | 55 | C | 0 | $179K |
| 32 | 63105 | Saint Louis | 55 | C | 0 | $736K |
| 33 | 63107 | Saint Louis | 55 | C | 0 | $57K |
| 34 | 63108 | Saint Louis | 55 | C | 0 | $337K |
| 35 | 63109 | Saint Louis | 55 | C | 0 | $245K |
| 36 | 63112 | Saint Louis | 55 | C | 0 | $216K |
| 37 | 63117 | Saint Louis | 55 | C | 0 | $330K |
| 38 | 63118 | Saint Louis | 55 | C | 0 | $211K |
| 39 | 63120 | Saint Louis | 55 | C | 0 | $52K |
| 40 | 63134 | Saint Louis | 55 | C | 0 | $92K |
| 41 | 63139 | Saint Louis | 55 | C | 0 | $199K |
| 42 | 63147 | Saint Louis | 55 | C | 0 | $70K |
| 43 | 63041 | Grubville | 53 | D | 0 | — |
| 44 | 63047 | Hematite | 53 | D | 0 | — |
| 45 | 63057 | Liguori | 53 | D | 0 | — |
| 46 | 63061 | Luebbering | 53 | D | 0 | $267K |
| 47 | 63065 | Mapaville | 53 | D | 0 | — |
| 48 | 63150 | Saint Louis | 53 | D | 0 | — |
| 49 | 63151 | Saint Louis | 53 | D | 0 | — |
| 50 | 63155 | Saint Louis | 53 | D | 0 | — |
| 51 | 63156 | Saint Louis | 53 | D | 0 | — |
| 52 | 63158 | Saint Louis | 53 | D | 0 | — |
| 53 | 63160 | Saint Louis | 53 | D | 0 | — |
| 54 | 63163 | Saint Louis | 53 | D | 0 | — |
| 55 | 63164 | Saint Louis | 53 | D | 0 | — |
| 56 | 63167 | Saint Louis | 53 | D | 0 | — |
| 57 | 63169 | Saint Louis | 53 | D | 0 | — |
| 58 | 63171 | Saint Louis | 53 | D | 0 | — |
| 59 | 63178 | Saint Louis | 53 | D | 0 | — |
| 60 | 63179 | Saint Louis | 53 | D | 0 | — |
| 61 | 63180 | Saint Louis | 53 | D | 0 | — |
| 62 | 63182 | Saint Louis | 53 | D | 0 | — |
| 63 | 63188 | Saint Louis | 53 | D | 0 | — |
| 64 | 63195 | Saint Louis | 53 | D | 0 | — |
| 65 | 63197 | Saint Louis | 53 | D | 0 | — |
| 66 | 63199 | Saint Louis | 53 | D | 0 | — |
| 67 | 63043 | Maryland Heights | 50 | D | 0 | $216K |
| 68 | 63044 | Bridgeton | 50 | D | 0 | $232K |
| 69 | 63074 | Saint Ann | 50 | D | 0 | $120K |
| 70 | 63111 | Saint Louis | 50 | D | 0 | $116K |
| 71 | 63116 | Saint Louis | 50 | D | 0 | $161K |
| 72 | 63119 | Saint Louis | 50 | D | 0 | $331K |
| 73 | 63121 | Saint Louis | 50 | D | 0 | $94K |
| 74 | 63126 | Saint Louis | 50 | D | 0 | $287K |
| 75 | 63127 | Saint Louis | 50 | D | 0 | $594K |
| 76 | 63131 | Saint Louis | 50 | D | 0 | $734K |
| 77 | 63132 | Saint Louis | 50 | D | 0 | $404K |
| 78 | 63133 | Saint Louis | 50 | D | 0 | $59K |
| 79 | 63137 | Saint Louis | 50 | D | 0 | $79K |
| 80 | 63141 | Saint Louis | 50 | D | 0 | $572K |
| 81 | 63143 | Saint Louis | 50 | D | 0 | $226K |
| 82 | 63146 | Saint Louis | 50 | D | 0 | $284K |
| 83 | 63114 | Saint Louis | 45 | D | 0 | $110K |
| 84 | 63122 | Saint Louis | 45 | D | 0 | $450K |
| 85 | 63123 | Saint Louis | 45 | D | 0 | $205K |
| 86 | 63124 | Saint Louis | 45 | D | 0 | $967K |
| 87 | 63125 | Saint Louis | 45 | D | 0 | $166K |
| 88 | 63128 | Saint Louis | 45 | D | 0 | $320K |
| 89 | 63129 | Saint Louis | 45 | D | 0 | $279K |
| 90 | 63135 | Saint Louis | 45 | D | 0 | $96K |
| 91 | 63136 | Saint Louis | 45 | D | 0 | $77K |
| 92 | 63144 | Saint Louis | 45 | D | 0 | $279K |
| 93 | 63088 | Valley Park | 40 | D | 0 | $232K |
| 94 | 63130 | Saint Louis | 40 | D | 0 | $286K |
Recommended Buyer Guides for Jefferson County
Strictly editorial — no paid placements influence which guides appear; the selection draws on NSF certifications and EPA detection records for water systems serving this county.
- Best Lead Paint Test Kits — 74.3% 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 Jefferson County, Missouri
Overview
Jefferson County in Missouri covers 94 ZIP codes with an average Home Safety Score of C (55/100).
10 of 94 ZIP codes have recorded EPA violations. 6 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.