On March 11, 2021, the United State Environmental Protection Agency (USEPA) published the proposal final Unregulated Contaminants Monitoring Rule 5 (UCMR5). This 5th UCMR will require monitoring of the drinking water entry points of public water systems across the nation for a host of chemicals of emerging concern (CECs), including Per- and Polyfluoroalkyl substances (PFAS), Lithium and also potentially Legionella, 1,2,3-Trichloropropane, Haloacetonitriles and Total Organic Fluorine (TOF). We will summarize these proposed new drinking water monitoring requirements and provide suggestions to prepare for successful implementation of these new requirements for your water system.