Data & Sources — Ashtabula County

How we built the Ashtabula County well water report: sample counts, data sources, and confidence tiers.

Sample Summary

148709 total samples analyzed for Ashtabula County. Data spans 1964 to 2024.

Confidence Tiers

Data Sources

This report aggregates data from the following public databases:

Methodology

Raw records are normalized to µg/L, deduplicated by sample ID, and filtered to remove certified outliers. Analyte names are mapped to EPA canonical forms. See the full methodology page for details.

Last updated: 2026-05-08