Book excerpt: As part of the ongoing Installation Restoration Program at Beale Air Force Base, California, 24 sites of concern have been identified. During the IRP Stage 2-1 Remedial Investigation, which is the subject of this technical report, 16 of the 24 sites were investigated through sampling and analysis of environmental media. Two of the 24 sites were investigated using surface geophysics only, and 1 of the sites was the subject of records search activities only. The remaining 5 sites did not receive any IRP actions during IRP Stage 2-1. This technical report summarizes the activities accomplished and results obtained during IRP Stage 2-1 Remedial Investigation, through four quarterly rounds of water sampling. Included in this report are discussions of the IRP program origin and objectives, environmental setting of Beale AFB, field and laboratory investigation methods, results obtained, and recommendations for future IRP actions. Eleven appendices are included which present data and relevant information regarding Stage 2-1 activities.