Louisville's water quality grade in KY reflects a middle-ground assessment — service areas range from fully compliant to violation-flagged in current EPA records.

Data: EPA SDWIS Last verified: 2026-06-04

Water Quality Map: Louisville, KY

Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.

A B C D F

Overview

We track water quality and home safety data for 66 ZIP codes in Louisville, Kentucky, covering 5 community water systems serving approximately 765,842 people.

No EPA violations recorded across any ZIP codes in Louisville — an excellent indicator of water quality.

Home Safety Score

Average Home Safety Score for Louisville: C (65/100)

The score combines three factors:

Factor	What It Measures
Water Quality	EPA violations and compliance history
Lead Levels	90th percentile lead concentration vs EPA action level
Radon Risk	EPA radon zone classification

Water Sources

Louisville water systems draw from: Surface water.

Lead & Copper

• Average lead level (90th percentile): 0.0011 mg/L (EPA action level: 0.015 mg/L)
• 0 ZIP codes exceed the EPA lead action level

Radon Risk

Dominant radon zone: Zone 1 (High Risk)

• Zone 1 (High): 65 ZIP codes
• Zone 2 (Moderate): 1 ZIP code
• Zone 3 (Low): 0 ZIP codes

The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.

Areas with No Violations

All ZIP Codes in Louisville

• 40201 [B]
• 40202 [C]
• 40203 [B]
• 40204 [C]
• 40205 [C]
• 40206 [C]
• 40207 [C]
• 40208 [C]
• 40209 [C]
• 40210 [B]
• 40211 [C]
• 40212 [C]
• 40213 [C]
• 40214 [C]
• 40215 [C]
• 40216 [C]
• 40217 [C]
• 40218 [C]
• 40219 [C]
• 40220 [C]
• 40221 [C]
• 40222 [C]
• 40223 [C]
• 40224 [C]
• 40225 [C]
• 40228 [C]
• 40229 [C]
• 40231 [C]
• 40232 [C]
• 40233 [C]
• 40241 [C]
• 40242 [C]
• 40243 [B]
• 40245 [C]
• 40250 [C]
• 40251 [B]
• 40252 [B]
• 40253 [C]
• 40255 [C]
• 40256 [C]
• 40257 [C]
• 40258 [C]
• 40259 [C]
• 40261 [C]
• 40266 [C]
• 40268 [C]
• 40269 [C]
• 40270 [C]
• 40272 [C]
• 40280 [C]
• 40281 [C]
• 40282 [C]
• 40283 [C]
• 40285 [C]
• 40287 [C]
• 40289 [C]
• 40290 [C]
• 40291 [C]
• 40292 [C]
• 40293 [C]
• 40294 [C]
• 40295 [C]
• 40296 [C]
• 40297 [C]
• 40298 [C]
• 40299 [C]

Data Sources

• Water quality: EPA Safe Drinking Water Information System (SDWIS)
• Lead/copper: EPA Lead and Copper Rule sampling data
• Radon: EPA Map of Radon Zones

Updated daily.

How Remediation Costs Compare in Louisville

Property equity in Louisville runs well ahead of estimated remediation costs — a cost-to-value ratio that sits in the low tier, meaning documented water and safety issues here are the kind homeowners can plan to address without treating the expense as a significant budget event relative to what their homes are worth.

Median Home Value

$220,200

Est. Remediation

$2,182

Remediation as % of home value 1.0%

Remediation costs in Louisville are relatively low compared to home values. The $1,455–$2,927 estimated range is a small fraction of median property value. Home values are 47% above the Kentucky average.

Louisville: Lead Risk & Vulnerable Populations

0.0011

mg/L Avg Lead (Limit: 0.015)

Why children are most at risk: The CDC states there is no safe level of lead exposure for children. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.

Lead risk in Louisville appears low overall, but individual homes may differ. Testing is the only way to confirm your water's lead content.

Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.

Louisville: Flood History & Water Damage Risk

NFIP data for Louisville documents 4412 flood insurance claims across the program's multi-decade tracking period, with 50% of ZIP codes mapped into FEMA flood zones. That level of exposure creates compounding risk during major flood events: treatment systems can be overwhelmed, wells can be contaminated, and distribution infrastructure can suffer backflow — all pathways by which flood events degrade local water quality beyond the physical damage.

4,412

Total FEMA Flood Claims

$13,787

Avg Claim Payout

50%

ZIPs in FEMA Flood Zones

~221

Est. Claims/Year

Louisville has a significant flood history with 4,412 FEMA flood insurance claims on record, averaging $13,787 per claim. With 50% of ZIP codes in FEMA-designated flood zones, flood risk is a major concern for homeowners and water quality.

How flooding affects water quality: Flood events can introduce sewage, agricultural runoff, and industrial chemicals into water supplies. Even after floodwaters recede, contamination can persist in wells and aging infrastructure. Flood damage can add significantly to the estimated <strong>$2,182</strong> remediation cost per household.

Residents in flood-prone areas should consider flood insurance even outside FEMA zones — over 25% of flood claims come from low-to-moderate risk areas. After any flood event, test your water before drinking.

Source: FEMA National Flood Insurance Program (NFIP) claims data, FEMA flood zone designations.