About SafeNest
How Grades Work
SafeNest evaluates the environmental health of US ZIP codes by analyzing publicly available EPA data. Each ZIP code receives grades across multiple categories — currently Water Quality and Toxic Sites — which are combined into a weighted overall grade.
The overall grade is a weighted average of all categories that have available data. If a category lacks sufficient data, it is excluded rather than penalizing the ZIP code.
Scoring Scale
| Grade | Score Range | Meaning |
|---|---|---|
| A | 3.50 - 4.00 | Excellent |
| B | 2.50 - 3.49 | Good |
| C | 1.50 - 2.49 | Fair |
| D | 0.50 - 1.49 | Poor |
| F | 0.00 - 0.49 | Critical |
Water Quality Methodology
Water quality scores start at 4.0 (perfect) and deduct points based on violations reported to the EPA’s Safe Drinking Water Information System:
Toxic Sites Methodology
Toxic site scores start at 4.0 and deduct based on proximity and severity of hazardous facilities:
Data Sources
Safe Drinking Water Information System
Tracks drinking water violations, enforcement actions, and water system information for public water systems across the United States.
Toxics Release Inventory
Annual reporting of toxic chemical releases and waste management activities by industrial facilities. Covers over 650 chemicals.
National Priorities List
Identifies the most contaminated sites in the country that pose the greatest risk to human health and the environment.
Resource Conservation and Recovery Act
Tracks hazardous waste generators, transporters, and treatment, storage, and disposal facilities, including compliance violations.
Insufficient Data
Some ZIP codes may show a “No Data” badge for one or more categories. This occurs when we cannot find matching EPA records — for example, if the area is served by a private well or no TRI-reporting facilities exist nearby.
When a category lacks data, it is excluded from the overall grade. A ZIP with only one category graded shows its overall grade based solely on that category.
Disclaimer
SafeNest is an informational tool and does not constitute professional environmental, health, or real estate advice. Grades are derived from publicly available EPA data and simplified scoring models. Actual conditions can vary significantly within a ZIP code. Always consult qualified professionals before making decisions. Data may not reflect the most recent conditions.