U.S. Home Safety Map — State-by-State Water Quality Scores

How Home Safety Scores Are Calculated

Each ZIP code's Home Safety Score (0–100) is a weighted composite of four environmental risk factors, each contributing 25% of the total score:

• Water Quality — EPA violation history from the Safe Drinking Water Information System (SDWIS). Health-based violations weigh more heavily than monitoring/reporting violations. Resolved violations are weighted at 0.25x.
• Lead & Copper — 90th percentile lead and copper levels from the Lead and Copper Rule (LCR) sampling. ZIPs exceeding the 15 ppb action level receive significant score penalties.
• Radon Risk — EPA radon zone classifications (Zone 1 = highest risk, Zone 3 = lowest risk) mapped by county.
• Flood Exposure — FEMA flood insurance claim history, including total claims, average payout, and recent claim activity.

Understanding the Grades

Scores translate to letter grades for quick reference:

• A (90–100) — Excellent. Minimal violations, low environmental risk across all four factors.
• B (80–89) — Good. Minor issues in one or two categories, generally safe.
• C (70–79) — Fair. Moderate risk factors present. Review your ZIP code report for details.
• D (60–69) — Below Average. Multiple risk factors or significant violations detected.
• F (below 60) — Poor. Serious concerns across multiple categories. Check your local water report.

Data Sources

All data comes from U.S. federal public records: EPA Safe Drinking Water Information System (SDWIS), EPA Lead and Copper Rule sampling data, EPA radon zone maps, FEMA National Flood Insurance Program (NFIP) claims, and CDC childhood blood lead surveillance. Data is updated quarterly.