Northern Mariana Islands Water Systems

Northern Mariana Islands community water systems are regulated by the EPA Safe Drinking Water Information System (SDWIS) under the Safe Drinking Water Act; each utility files compliance results with the state's primacy agency and, for federally listed contaminants, with the U.S. Environmental Protection Agency directly. PlainEnviro's health-based SDWIS extract above counts health-based exceedances only -- monitoring and reporting violations are not present in these figures.

Violation counts reflect both infrastructure realities and reporting diligence, a state with more small rural systems will accumulate more monitoring-type violations without necessarily delivering worse water. Health-based violations are the stronger safety signal. A past violation does not itself indicate current unsafe water; utilities must notify customers, remediate, and publish an annual Consumer Confidence Report. All numbers below draw directly from the federal SDWIS record.