About this site
Tapcensus turns the EPA's public drinking water compliance database into a page for every state, county, public water system, and contaminant in the United States, so that anyone can check the system that serves them.
What it shows
Compliance records for 142,155 active public water systems in all 50 states and the District of Columbia: violations reported to EPA in the past three years, which rules and contaminants were involved, whether a violation is still open, EPA's serious-violator and health-flag designations, population served, water source, and a link to the EPA facility report.
What it does not show
Measured contaminant levels, private wells, or a guaranteed match between one address and one utility. Results are matched to your county and ordered by distance; when your location falls within the outer bounds of a system's EPA service area, that system is shown first. Measured values are published by each system in its annual Consumer Confidence Report.
Where the data comes from
All records come from the EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System (SDWIS). We retrieve each state separately and show the retrieval date on every page. We do not alter EPA's terms or values. County boundaries, ZIP code areas, and place names come from the U.S. Census Bureau. Street addresses are resolved with the Census Geocoder.
System locations come from EPA's Public Water System Service Area Boundaries dataset (version 3.0, March 2026, published under the MIT licence), which maps the area each system serves; we store the centre and outer bounds of each area. Where EPA publishes no boundary, the centre of the first town or ZIP code the system is listed as serving is used, from Census Bureau files. Each system page says which applies.
Limitations
SDWIS reflects what systems and states report to EPA, with a lag of three to six months. It may not capture every local enforcement action or the latest monitoring results. For official determinations, contact your state's drinking water program.
Who runs it
This is an independent project. It is not affiliated with, or endorsed by, the U.S. EPA or any state drinking water program. Questions and corrections: hello@tapcensus.com.
The site aims to meet WCAG 2.1 level AA. If something on it does not work for you, tell us at hello@tapcensus.com and we will fix it.