ARCHIVED REPORTS_XR0002830 - Laserfiche WebLink

Home Browse Search

• FIELD INVESTIGATION To investigate the extent of residual soil and groundwater contamination at the site, a total of seven soil borings were advanced in the vicinities of the former USTs All field activities were performed in accordance with Smith Technology's Workplan for Subsurface Investigation at Continental Grain 1805 Harbor Street, Stockton, California, dated September 10, 1997 This workplan was approved by PHSlEHD on October 1, 1997 with minor modifications Soil Sample Collection On October 7, 1997, a Smith Technology geologist supervised the advancement of one soil boring to 31 feet bgs, one soil boring to 26 feet bgs, and five soil borings to 20 feet bgs Soil borings SBI through SB6 were placed in the vicinity of the former 10,000-gallon UST and soil boring SB7 was placed in the vicinity of the former 750-gallon UST A site plan with soil boring locations is shown on Figure 2 Fisch Environmental, California License C57 683865, advanced the borings using a truck mounted Geoprobe® narrow diameter ng employing direct push technology Soil samples were collected from borings SBI and SB7 at five-foot intervals in acetate sampling tubes and were described according to the Unified Soil Classification System A soil sample was also collected from boring SB2 at 15 feet bgs Descriptions of soil types encountered and sample collection intervals are presented on the boring logs contained in Attachment 1 Each soil sample was field screened with a Photoiomzation Detector (PID) for the presence of volatile organic compounds Sample tubes were then sealed at each end using Teflon tape and plastic end caps, labeled, and placed on ice Selected soil samples were kept on ice and delivered under chain-of-custody documentation to a State-certified American Environmental Network (AEN) laboratories, (DOHS Cert No 1172) for chemical analysis Field notes and PID readings are contained in Attachment 2 During the advancement of borings SB2 and SB3, large amounts of free product were present in the groundwater samples With the approval of Mr Bruce Askanas of PHSIEHD, it was decided in the field to define the groundwater plume Soil sampling was discontinued to ensure that there was sufficient time to define the groundwater plume Groundwater Sample Collection One groundwater sample was collected from each boring at the depth groundwater was first encountered, approximately 20 feet bgs A Geoprobe® Screen Point 15 Groundwater Sampler was threaded onto the leading end of the Geoprobe after groundwater had been encountered When the sampler was advanced, O-ring seals and an expendable drive point provided a watertight system to ensure sample integrity • w 1625001reporlslsum doc 2 • SMTN