Laserfiche WebLink
1 I <br /> Project No S8080-06-02 <br /> May 5, 1995 <br /> soil within the soil gas survey boundaries, the soil gas analytical data appears to be non- <br /> representative, is inconclusive and did not aid in the further delineation of impacted soil ti <br /> t Analytical results from the collection of soil samples indicated that residual TPHg and TPHd were <br /> present in soil between the depths of 17 and 43 feet bgs below the central and southeast portions <br /> of the site Results also indicated that the drilling of offsite borings would be required to achieve <br />' plume delineation to the north and east of the site boundaries <br />' The results of the July 1994 Geocon investigation, which included ,a detailed summary of the <br /> previous investigative results, was included in Geocon's previous status report entitled "Interim <br /> Env uronmental Assessment Status Report" dated August 31, 1994 The August 1994 status report, <br /> which included boring logs, analytical reports, chain-of-custody records, etc was forwarded to the <br /> San Joaquin County Environmental Health Division (SJCEHD) <br /> 1 4 Summary of Current Environmental Study <br /> In November 1994,Geocon drilled eight soil borings,constructed and sampled two additional offsite <br /> groundwater monitoring wells and constructed five additional onsite vapor extraction wells The <br /> purpose of the November 1994 investigation performed by Geocon was to complete the vertical and <br /> lateral delineation of TPHg and TPHd in soil (both onsite and offsite) and further evaluate whether <br /> the chemical compounds detected in groundwater are from offsite sources <br /> 1 <br /> New vapor extraction wells were designated for installation at locations that may require remedial <br />' action as a time and cost saving measure even though plume delineation at some of these well sites <br /> was complete A vapor extraction pilot test was performed to evaluate the use of vapor extraction <br /> 1 as a soil remediation technology The following sections of this PAR 1) summarize the work <br /> performed by Geocon in November 1994, which has resulted in the delineation of both onsite and <br /> offsite residual BTEX, TPHg and TPHd in vadose zone soil, 2) presents an evaluation of the <br /> -8- <br /> 1I <br />