EPA’s Safe Drinking Water Information System Federal Version (SDWIS/FED) includes information on populations served and violations of maximum contaminant levels or required treatment techniques by the nation’s 160,000 public water systems. For each calendar year, SDWIS/FED violation data for the nation’s 50,000 community water systems were obtained from EPA Office of Ground Water and Drinking Water (OGWDW), listing all violations that occurred during part or all of that year.

• Environments and Contaminants: Drinking Water (PDF)(8 pp, 131 K)