Metric glossary
Environmental
Drinking water compliance
EPA ECHO drinking water enforcement and compliance
What is it?
EPA's record of every public water system's compliance with Safe Drinking Water Act standards, including violation history for contaminants like nitrates, lead, arsenic, and disinfection byproducts.
Why it matters
Persistent violations indicate residents are drinking water that may exceed federal safety limits for chemical or microbial contaminants linked to cancer, developmental harm, and acute illness.
Reference value
Counties with chronic violations across multiple water systems, or repeat violations on the same system, are higher concern than isolated single events.
Data source
EPA Enforcement and Compliance History Online (ECHO) · View source →