ARCHIVED REPORTS_XR0013090 - Laserfiche WebLink

Home Browse Search

2.1 Motor/Hydraulic Oil UST Removal On December 17, 2010, a Ground Zero technician marked the site with white paint for underground utility clearance. On December 21, 2010 Underground Service Alert was contacted regarding upcoming site activities and ticket #378724 was issued. Prior to removing the Motor/Hydraulic Oil UST permit SR#0061668 was obtained from EHD. On December 29, 2010, Joe Vazquez of Ground Zero, Anne Ogrey of Spreckels Sugar and Harlin Knoll of EHD supervised the removal of a 350-gallon Motor/Hydraulic Oil UST located near the former UST B location (Figure 2). Oxygen (02) and lower explosive limit (LEL) measurements were taken by Marty Thorpe of Thorpe Oil Inc (Thorpe). Based on the 02 and LEL measurements, the inspector from the Tracy Fire Department approved the tank pull. The welded metal UST was removed by Thorpe and found to be in poor condition. Thorpe excavated the area around and beneath the UST to a depth of 8 feet below ground surface (bgs). Approximately 4 yd of excavated soil was stockpiled on plastic and covered with plastic. On January 3, 2011, the Motor/Hydraulic Oil UST was taken to Schnitzer Steel Products in Rancho Cordova, California. The location of the Motor/Hydraulic Oil UST and stockpile location are shown in Figure 3. 2.1.1 Excavation and Stockpile Sampling Under the direction of Mr. Knoll, Mr. Vazquez collected a soil sample from the floor of the excavation at 8 feet bgs. The sample had a bluish hue, slight oil odor, and was clay. Another soil sample was collected from the stockpile. The soil samples were collected in 6-inch brass sleeves, the ends covered with Teflon® sheets and capped, uniquely labeled, placed into an ice chest cooled to approximately 4°C, and transported to Argon Laboratories (Argon) in Ceres, California (ELAP No. 2359) under chain of custody protocol for analysis. 2.1.2 Analytical Results The soil samples collected on December 29, 2010 were submitted for the following analyses: • Total petroleum hydrocarbons as diesel (TPHd)by EPA method 8015M; and • Benzene, toluene, ethylbenzene, and total xylenes (BTEX) and methyl tert-butyl ether (MTBE)by EPA method 8260B. Analytical results are summarized below and in Table 1. The laboratory analytical report is included in Attachments A-1. • Beneath the Motor/Hydraulic Oil UST (sample ID UST101229): All analyzed constituents were below laboratory detection limits. • Stockpile (sample ID UST Stockpile): TPHD was detected at 310 milligrams per kilogram (mg/Kg). All other analyzed constituents were below laboratory detection limits. -2 -