This plan provides a description of the groundwater and surface water quality monitoring activities planned for calendar year (CY) 2003 at the U.S. Department of Energy (DOE) Y-12 National Security Complex that will be managed by the Y-12 Groundwater Protection Program (GWPP). Groundwater and surface water monitoring performed by the GWPP during CY 2003 will be in accordance with the following requirements of DOE Order 5400.1: to evaluate and maintain surveillance of existing and potential groundwater contamination sources; to provide for the early detection of groundwater contamination and determine the quality of groundwater and surface water where contaminants are most likely to migrate beyond the Oak Ridge Reservation property line; to identify and characterize long-term trends in groundwater quality at Y-12; and to provide data to support decisions concerning the management and protection of groundwater resources.