zipradar

Topic · EPA SDWIS

Water quality by ZIP code

Every community water system (CWS) in the United States reports violations, lead-copper results, and treatment data to the EPA. zipradar federates that feed per ZIP code.

Last verified 2026-04-24 · methodology

What zipradar shows

Pages show the CWS serving the address, any health-based violations in the last 3 years, most recent lead and copper sampling result, and a link to the primary SDWIS record.

Refresh cadence

Quarterly (federal mandate). zipradar honors the regulator's publishing cadence; stale data is flagged rather than silently served.

Limitations

Where a ZIP is served by multiple water systems, zipradar shows the dominant CWS by population served and lists alternates. Private well water is not covered.

Primary source

EPA SDWIS

Look up water quality by ZIP

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