DOE prepared this EIS to analyze the potential environmental impacts of alternatives for conducting cleanup activities in Area IV of the Santa Susana Field Laboratory and the adjoining Northern Buffer Zone, located in Ventura County, California. Residual chemicals and radionuclides from historical operations in Area IV associated with soil, buildings, and groundwater, as well as soil contamination in the Northern Buffer Zone that is contiguous to and emanating from Area IV, need to be cleaned up.