Corrective Action Decision Document for Corrective Action Unit 490: Station 44 Burn Area, Tonopah Test Range, Nevada (Rev. No.: 0, February 2001)

This Corrective Action Decision Document identifies and rationalizes the U.S. Department of Energy, Nevada Operations Office's selection of a recommended Corrective Action Alternative (CAA) appropriate to facilitate the closure of Corrective Action Unit (CAU) 490, Station 44 Burn Area, Tonopah Test Range (TTR), Nevada, under the Federal Facility Agreement and Consent Order. Corrective Action Unit 490 is located on the Nellis Air Force Range and the Tonopah Test Range and is approximately 140 miles northwest of Las Vegas, Nevada. This CAU is comprised of four Corrective Action Sites (CASs): 03-56-001-03BA, Fire Training Area (located southwest of Area 3); RG-56-001-RGBA, Station 44 Burn Area (located west of Main Lake); 03-58-001-03FN, Sandia Service Yard (located north of the northwest corner of Area 3); and 09-54-001-09L2, Gun Propellant Burn Area (located south of the Area 9 Compound on the TTR). A Corrective Action Investigation was performed in July and August 2000, and analytes detected during the corrective action investigation were evaluated against preliminary action levels to determine contaminants of concern (COCs). There were no COCs identified in soil at the Gun Propellant Burn Area or the Station 44 Burn Area; therefore, there is no need for corrective actions at these two sites. Five soil samples at the Fire Training Area and seven at the Sandia Service Yard exceeded PALs for total petroleum hydrocarbons-diesel. Upon the identification of COCs specific to CAU 490, Corrective Action Objectives were developed based on a review of existing data, future use, and current operations at the TTR, with the following three CAAs under consideration: Alternative 1 - No Further Action, Alternative 2 - Closure In Place - No Further Action With Administrative Controls, and Alternative 3 - Clean Closure by Excavation and Disposal. These alternatives were evaluated based on four general corrective action standards and five remedy selection decision factors. Based on the results of this evaluation, the preferred choice for CAU 490 was Alternative 3. This alternative was judged to meet all requirements for the technical components evaluated, all applicable state and federal regulations for closure of the site, and will eliminate potential future exposure pathways to the contaminated soils at this site