Free Water Violations API

A clean, simple REST API for U.S. drinking water violation data from the EPA's Safe Drinking Water Information System. No API key required. Returns JSON. Updated quarterly.

The EPA's own SDWIS API uses CSV batches with pagination and cryptic codes. This API gives you human-readable JSON with a single request.

GET /api/v1/system/{pwsid}

Returns system details, violation summary, and recent violations for a specific water system.

curl https://waterviolations.org/api/v1/system/CO0800000

GET /api/v1/zip/{zip}

Returns water systems serving a ZIP code with their violation counts.

curl https://waterviolations.org/api/v1/zip/80202

GET /api/v1/state/{state}

Returns state-level summary: total systems, violations, health-based counts, and top counties.

curl https://waterviolations.org/api/v1/state/co

No API key required. Please keep requests reasonable (a few per second). If you need bulk data, use the CSV downloads instead.

This data is sourced from the U.S. EPA and is in the public domain. If you use this API in a project, a link back to WaterViolations.org is appreciated but not required.

WaterViolations.org API. Data from U.S. EPA Safe Drinking Water
Information System (SDWIS). https://waterviolations.org/api