ARCHIVED REPORTS_XR0003946 - Laserfiche WebLink

Home Browse Search

L o r� • Mr Harlin Knoll November 29, 1995 (9347-0085) C • Submit ten soil samples collected from the borings to a state-certified laboratory for chemical analysis • Prepare this technical report presenting the results of this investigation Site Description The site is a service station located on the Lodi South 7 5 minute topographic map at Township 2 North, Range 6 East, Section 13, northeast 114, southeast 114 According to the San Joaquin County assessors office, the parcel number is 092-110-09 The 0 80 acre site is located in an agricultural/residential area of Stockton, at the southeast corner of the intersection of Moreland Court and Hammer Lane According to the January 9, 1991 Problem Assessment Report prepared by Delta Environmental Consultants (Delta), three 10,000-gallon double-walled fiberglass fuel USTs and one 550-gallon double-walled UST are currently onsite Background On April 4, 1988, Delta performed a pre-UST removal site assessment Soil borings B-1 through B-4 were advanced to 21 feet bg Borings B-5 and B-6 were advanced to 16 5 feet bg • Results of field screening indicated soil vapors were present in the soil samples collected from the soil borings No soil samples were submitted for chemical analysis The results are summanzed in Delta's April 19, 1988, letter report In December 1988 and January 1989, three single-walled steel USTs (one 7,500-gallon and two 5,000-gallon) and associated product piping were removed Total petroleum hydrocarbons as gasoline (TPH-G) was detected at 1,030 parts per million (ppm) in soil sample TS-2 collected from the excavation at 15 feet bg (Figure 2) Petroleum hydrocarbons were detected in soil samples collected from beneath the western dispenser islands at approximately 4 feet bg (Figure 2, PL-5 and PL-6) Laboratory analyses detected TPH-G concentrations at 1,130 ppm in soil sample PL-5 and at 117 ppm in sample PL-6 Benzene was also detected at 0 680 ppm in sample PL-6 Approximately 200 cubic yards (yd}) of petroleum hydrocarbon- impacted soil was excavated during UST removal The soil was disposed of at Forward Landfill in Manteca, California The replacement USTs (double-walled fiberglass) were installed on January 9, 1989 According to blueprints, they overlapped the west end of the former UST basin The overlap has not been clearly represented in Delta's Tank Closure Report, dated April 7, 1989 On August 8, 1989, soil borings SB-7 and SB-8 were advanced to 31 5 and 26 5 feet bg, respectively Boring SB-7 was located approximately 15 feet northwest of product line sample PL-5 A soil sample was collected at 11 5 and 26 5 feet bg Boring SB-8 was located within 10 feet of UST excavation sample TS-2 A soil sample was collected at 16 5 and 26 5 feet bg -2- 9347-0085 ARP