BetaBetaDataset
To provide a national repository of drinking water contaminant occurrence data for supporting drinking water research, regulatory analysis, rulemaking, and public health protection under the Safe Drinking Water Act (SDWA)
EPA developed the National Contaminant Occurrence Database (NCOD) to satisfy statutory requirements in the 1996 Amendments to the Safe Drinking Water Act (SDWA).
The database includes occurrence information for regulated and unregulated contaminants in public water systems, including: Unregulated Contaminant Monitoring Rule (UCMR) occurrence data, Six-Year Review compliance monitoring data, ambient and source water data, analytical drinking water sample results, exposure and occurrence estimates, and contaminant occurrence information used for rule evaluation and regulatory assessment.
The data are collected through drinking water monitoring programs conducted by public water systems, states, and EPA regulatory monitoring initiatives under the Safe Drinking Water Act. Major data sources include UCMR monitoring, SDWIS compliance reporting, ambient water monitoring programs, and other public and private contaminant occurrence datasets that undergo quality review and representativeness analysis before inclusion in NCOD