Addendum to the Corrective Action Investigation Plan for Corrective Action Unit 321: Area 22 Weather Station Fuel Storage, Nevada Test Site, Nevada (Rev. 0, November 2000)

This addendum to the Corrective Action Investigation Plan (CAIP) contains the U.S. Department of Energy, Nevada Operations Office's approach to determine the extent of contamination existing at Corrective Action Unit (CAU) 321. This addendum was required when the extent of contamination exceeded the estimate in the original Corrective Action Decision Document (CADD). Located in Area 22 on the Nevada Test Site, Corrective Action Unit 321, Weather Station Fuel Storage, consists of Corrective Action Site 22-99-05, Fuel Storage Area, was used to store fuel and other petroleum products necessary for motorized operations at the historic Camp Desert Rock facility. This facility was operational from 1951 to 1958 and dismantled after 1958. Based on site history and earlier investigation activities at CAU 321, the contaminant of potential concern (COPC) was previously identified as total petroleum hydrocarbons (diesel-range organics). The scope of this corrective action investigation for the Fuel Storage Area will include the selection of biased sample locations to determine the vertical and lateral extent of contamination, collection of soil samples using rotary sonic drilling techniques, and the utilization of field-screening methods to accurately determine the extent of COPC contamination. The results of this field investigation will support a defensible evaluation of corrective action alternatives and be included in the revised CADD