ARCHIVED REPORTS XR0006065 - Laserfiche WebLink

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. GROUNDWATER MONITORING Groundwater Levels On April 21, 1995, Apex personnel collected groundwater-level measurements from all six wells All groundwater elevations were measured to the nearest 0 01 foot, referenced to the surveyed top-Of=casing elevations, and conducted according to the Apex standard operating procedures (SOP)mchrded as Attachment 1 Liquid-level measurements collected since January 1993 are summanzed in Table 1 Figure 3 is a potentiometric surface map of the shallow water-bearmg zone on April 21, 1995 Groundwater Sampting and Analysis On April 21, 1995, Apex personnel collected groundwater samples from all six monitoring wells (MW-1B,MW-2 through MW-6) The samples were submitted, under chem-of custody, to Sparger Technology, luc , of Sacramento, California, a state-certified analytical laboratory All samples were collected according to the Apex SOP included in Attachment 1 Analytical results smce January 1992 for total petroleum hydrocarbons (TPH), as gasoline, and benzene, toluene, ethylbenzene and total xylenes are summarized in Table 2 The laboratory analytical reports and cham-of-custody form are included in Attachment 2 VAPOR EXTRACTION RESULTS On December 6, 1994, a soil vapor extraction system cons>sting of an R S I SAVE System was installed at the site The vapor extraction system was mstalled per San Joaquin Valley Unified Air Pollution Control District Permit conditions The vapor extraction system consists of an internal combustion engine with catalytic converters mounted on the exhaust pipe The system was started on December 6, 1994, and after adjustments, has been operated continuously since December 13, 1994 Durmg this reporting period soil vapor flow to the system has vaned from 43 cubic feet per minute(cfiin) on January 24, 1995, to 15 chn on March 7, 1995 Vapor samples were collected from the system influent and eluent on February 21, 1995, to demonstrate comphance with San Joaquin Valley Unified Air Pollution Control District Permit The initial vapor extraction rate was 16 standard cubic feet per mmute (SCFM) Based on the vapor sample analytical results the system extraction rate was 0 23 pounds per day(lb /day) as gasoline Benzene was not detected and petroleum constituent discharge rates were essentially zero Air analytical results are contained in Attachment 2 System operating data and backup calculations are contained in Attachment 3 The system was shut down on March 21, 1995, for use at another facility A replacement system consisting of a 100 cfni blower with carbon emission controls has been permitted for this site The replacement system blower has been ordered and will be installed and started as soon as it is delivered to Apex 2