Jefferson County, Kentucky
78 ZIP codes · Avg score 61/100 · Grade C · Updated 2026-06-03
Although much of Jefferson County meets baseline standards, some of its 78 ZIP codes show violations that merit closer attention.
How Jefferson County Compares
How Jefferson County Compares
Jefferson County scores 0 points above the Kentucky state average (61/100) and 7 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Jefferson County, Kentucky
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Estimated additional annual cost per homeowner: $1,079, driven primarily by flood
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $1,079
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
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.
Water Systems with Most Violations
Top 5 systems in Jefferson County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | LOUISVILLE WATER COMPANY | 764,769 | 0 |
| 2 | Shelbyville Water & Sewer Commission | 23,760 | 0 |
| 3 | Taylorsville Water Works | 22,286 | 0 |
| 4 | WEST SHELBY WATER DISTRICT | 6,994 | 0 |
| 5 | Oldham County Water District | 38,409 | 0 |
8 total water systems serve Jefferson County.
All ZIP Codes in Jefferson County
78 ZIP codes tracked in Jefferson County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 40203 | Louisville | 70 | B | 0 | $179K |
| 2 | 40210 | Louisville | 70 | B | 0 | $93K |
| 3 | 40243 | Louisville | 70 | B | 0 | $298K |
| 4 | 40251 | Louisville | 70 | B | 0 | — |
| 5 | 40252 | Louisville | 70 | B | 0 | — |
| 6 | 40221 | Louisville | 66 | C | 0 | — |
| 7 | 40224 | Louisville | 66 | C | 0 | — |
| 8 | 40225 | Louisville | 66 | C | 0 | — |
| 9 | 40231 | Louisville | 66 | C | 0 | — |
| 10 | 40232 | Louisville | 66 | C | 0 | — |
| 11 | 40233 | Louisville | 66 | C | 0 | — |
| 12 | 40250 | Louisville | 66 | C | 0 | — |
| 13 | 40253 | Louisville | 66 | C | 0 | — |
| 14 | 40255 | Louisville | 66 | C | 0 | — |
| 15 | 40256 | Louisville | 66 | C | 0 | — |
| 16 | 40257 | Louisville | 66 | C | 0 | — |
| 17 | 40259 | Louisville | 66 | C | 0 | — |
| 18 | 40261 | Louisville | 66 | C | 0 | — |
| 19 | 40266 | Louisville | 66 | C | 0 | — |
| 20 | 40268 | Louisville | 66 | C | 0 | — |
| 21 | 40269 | Louisville | 66 | C | 0 | — |
| 22 | 40270 | Louisville | 66 | C | 0 | — |
| 23 | 40280 | Louisville | 66 | C | 0 | — |
| 24 | 40281 | Louisville | 66 | C | 0 | — |
| 25 | 40282 | Louisville | 66 | C | 0 | — |
| 26 | 40283 | Louisville | 66 | C | 0 | — |
| 27 | 40285 | Louisville | 66 | C | 0 | — |
| 28 | 40287 | Louisville | 66 | C | 0 | — |
| 29 | 40289 | Louisville | 66 | C | 0 | — |
| 30 | 40290 | Louisville | 66 | C | 0 | — |
| 31 | 40292 | Louisville | 66 | C | 0 | — |
| 32 | 40293 | Louisville | 66 | C | 0 | — |
| 33 | 40294 | Louisville | 66 | C | 0 | — |
| 34 | 40295 | Louisville | 66 | C | 0 | — |
| 35 | 40296 | Louisville | 66 | C | 0 | — |
| 36 | 40297 | Louisville | 66 | C | 0 | — |
| 37 | 40298 | Louisville | 66 | C | 0 | — |
| 38 | 40202 | Louisville | 65 | C | 0 | $340K |
| 39 | 40204 | Louisville | 65 | C | 0 | $315K |
| 40 | 40208 | Louisville | 65 | C | 0 | $153K |
| 41 | 40209 | Louisville | 65 | C | 0 | $128K |
| 42 | 40211 | Louisville | 65 | C | 0 | $98K |
| 43 | 40212 | Louisville | 65 | C | 0 | $78K |
| 44 | 40215 | Louisville | 65 | C | 0 | $107K |
| 45 | 40217 | Louisville | 65 | C | 0 | $221K |
| 46 | 40223 | Louisville | 65 | C | 0 | $344K |
| 47 | 40228 | Louisville | 65 | C | 0 | $220K |
| 48 | 40229 | Louisville | 65 | C | 0 | $197K |
| 49 | 40241 | Louisville | 65 | C | 0 | $349K |
| 50 | 40242 | Louisville | 65 | C | 0 | $293K |
| 51 | 40245 | Louisville | 65 | C | 0 | $433K |
| 52 | 40291 | Louisville | 65 | C | 0 | $265K |
| 53 | 40206 | Louisville | 60 | C | 0 | $276K |
| 54 | 40220 | Louisville | 60 | C | 0 | $250K |
| 55 | 40258 | Louisville | 60 | C | 0 | $173K |
| 56 | 40272 | Louisville | 60 | C | 0 | $170K |
| 57 | 40299 | Louisville | 60 | C | 0 | $275K |
| 58 | 40205 | Louisville | 55 | C | 0 | $362K |
| 59 | 40207 | Louisville | 55 | C | 0 | $402K |
| 60 | 40213 | Louisville | 55 | C | 0 | $169K |
| 61 | 40214 | Louisville | 55 | C | 0 | $177K |
| 62 | 40216 | Louisville | 55 | C | 0 | $155K |
| 63 | 40218 | Louisville | 55 | C | 0 | $196K |
| 64 | 40219 | Louisville | 55 | C | 0 | $186K |
| 65 | 40222 | Louisville | 55 | C | 0 | $347K |
| 66 | 40018 | Eastwood | 53 | D | 0 | — |
| 67 | 40023 | Fisherville | 53 | D | 0 | $430K |
| 68 | 40025 | Glenview | 53 | D | 0 | $1202K |
| 69 | 40047 | Mount Washington | 53 | D | 0 | $260K |
| 70 | 40056 | Pewee Valley | 53 | D | 0 | $319K |
| 71 | 40027 | Harrods Creek | 40 | D | 0 | — |
| 72 | 40041 | Masonic Home | 40 | D | 0 | $593K |
| 73 | 40109 | Brooks | 40 | D | 0 | $240K |
| 74 | 40129 | Hillview | 40 | D | 0 | — |
| 75 | 40166 | Shepherdsville | 40 | D | 0 | — |
| 76 | 40118 | Fairdale | 35 | F | 0 | $141K |
| 77 | 40165 | Shepherdsville | 35 | F | 0 | $243K |
| 78 | 40059 | Prospect | 30 | F | 0 | $534K |
Recommended Buyer Guides for Jefferson County
Editorial methodology pairs each documented risk in this county with the buyer category that addresses it, drawing on water-quality detections, housing-stock lead exposure, EPA Radon Zone designation, and FEMA flood and wildfire ratings. NSF-certified options surface where applicable, and products that match the specific contaminant take priority.
- Best Radon Test Kits — EPA Radon Zone 1 (highest risk) dominant in county
- 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, Kentucky
Overview
Jefferson County in Kentucky covers 78 ZIP codes with an average Home Safety Score of C (61/100).
No EPA violations recorded across any tracked ZIP codes in Jefferson County.
← Back to Kentucky 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.