U.S. Drinking Water Quality and Home Safety Scores by ZIP Code

EPA Safe Drinking Water Information System (SDWIS) data provides water quality violations, 90th percentile lead and copper levels, and county-level radon zones for over 6,300 U.S. ZIP codes. The dataset includes a composite Home Safety Score from 0 to 100 with an A-F grade. It is updated weekly and sourced from the zipcheckup.com methodology.

Use Cases

• Mapping environmental health disparities based on ZIP code-level contaminant levels.
• Assessing property-level safety risks using the composite Home Safety Score.
• Tracking compliance with drinking water regulations via reported violation data.
• Analyzing correlations between radon zones and other water quality metrics.

Strengths

• Covers a specific scale of over 6,300 U.S. ZIP codes.
• Includes a derived composite score (0-100, A-F grade) for home safety.
• Updated weekly, indicating active maintenance.
• Published under a permissive CC-BY-4.0 license.

Limitations

• Column names and exact row counts are not provided in the source metadata.
• Radon data is aggregated at the county level, not ZIP code level.
• The future 'last updated' date (2026-03-18) suggests a potential metadata error.

Provenance

Source

EPA Safe Drinking Water Information System (SDWIS), processed via zipcheckup.com methodology.

Collection Method

Data compilation and scoring methodology described at zipcheckup.com/methodology.

Freshness

Last updated 2026-03-18 (note: this is a future date, which may be an error).

Geography

United States, by ZIP code.