Our Methodology: How WellWaterPeek Analyzes Water Quality Data

Data Sources

Our water quality data comes from publicly available sources including:
- EPA SDWIS: Safe Drinking Water Information System
- USGS NAWQA: National Water-Quality Assessment Program
- State environmental agencies: State-level monitoring and compliance data
- CDC: Health-related water quality data

Calculation Method

For each state and contaminant combination, we analyze: average levels detected, maximum levels recorded, percentage of samples exceeding EPA MCLs, number of affected wells, and associated testing and treatment costs. Risk levels (minimal, low, moderate, high) are assigned based on the percentage of wells exceeding EPA limits and the severity of health effects.

Limitations

Private well data is inherently limited because testing is voluntary and not centrally reported. Our estimates use available monitoring data and statistical models to approximate conditions. Actual water quality at any specific well depends on local geology, well construction, and nearby land use. Always test your own well.

Updates

We update our database as new monitoring data becomes available, typically annually. Current data reflects 2025 values.