This Corrective Action Decision Document has been prepared for Corrective Action Unit (CAU) 322, Areas 1 and 3 Release Sites and Injection Wells, Nevada Test Site, Nevada, in accordance with the Federal Facility Agreement and Consent Order (1996). Corrective Action Unit 322 is comprised of the following corrective action sites (CASs): 01-25-01- AST Release Site; 03-25-03- Mud Plant and AST Diesel Release; 03-20-05- Injection Wells and BOP Shop. The purpose of this Corrective Action Decision Document is to identify and provide the rationale for the recommendation of a corrective action alternative for each CAS within CAU 322. Corrective action investigation activities were performed from April 2004 through September 2004, as set forth in the Corrective Action Investigation Plan. The purposes of the activities as defined during the data quality objectives process were: Determine if contaminants of concern (COCs) are present; If COCs are present, determine their nature and extent; Provide sufficient information and data to recommend appropriate corrective actions for the CASs.