ARCHIVED REPORTS_XR0010741 - Laserfiche WebLink

Home Browse Search

• Closure Report The Southland Corporation,9110 Thornton Road Stockton CA December 5 19955 and delivered to GTEL Environmental Laboratories in Concord, California under chain-of-custody (COC) manifest Samples were analyzed for BTEX and TPH-G by EPA methods 50301802018015 modified 32 Sod Confinnation Borings (August 1995) Groundwater Technology supervised the drilling of seven soil bonngs (K through Q) between August 23 and 25, 1995 to 45 feet BGS using a truck-mounted drill ng equipped with 8-inch outside diameter (O D) hollow-stem augers All drilling equipment was steam cleaned prior to drilling each boring, and sampling equipment was washed in an Alconox(detergent) solution and rinsed with water between sampling intervals All steam-clean water generated during drilling was placed in Department of Transportation (DOT)-approved 55-gallon drums stored adjacent to the equipment compound on site Soil samples were collected from each borehole at 5-foot intervals and at the bottom of the borings, beginning at approximately 5 feet BGS Samples were collected using a 2 5-inch O D split-spoon sampler, lined with three 2-inch-diameter by 6-inch-long brass sample tubes The sampler was driven 18 inches ahead of the augers at each sample point Soil samples were field screened for hydrocarbon vapors using a photo-ionization detector(PID) Soil was logged using the Unified Soil Classification System by a Groundwater Technology field geologist working under the supervision of a • California registered geologist One sample tube from each 5-foot interval was sealed, labeled, and placed on ice to an insulated container for transport under COC manifest to GTEL Environmental Laboratories in Concord, California A total of 38 soil samples were submitted for laboratory analysis for BTEX and TPH-G using EPA methods 5030/802018015 modified 40 DISTRIBUTION OF PETROLEUM HYDROCARBONS IN SOIL AND GROUNDWATER An unknown quantity of petroleum hydrocarbons was present in the subsurface prior to assessment and remediation Initial, removed, and remaining petroleum hydrocarbons are summarized in Table 4 and discussed below 41 Liquid Phase Hydrocarbons The initial distribution of LPH is illustrated on Figure 13 LPH had been detected at least once in wells MW-1, MW-3, MW-4, and PW-3 Approximately 760 gallons of LPH were removed between May 1986 and August 1988 (Table 4) by hand bailing and the product recovery system LPH has not been detected/measured in any wells on site since August 1988 Based on the lack of measurable LPH in monitoring wells for the past seven years, operation of the vapor extraction system, lack of dissolved G7osure2 rpt(3T)4L-6 1) 11=51 Q�OUNIIAVM 1,1? 11=1 '_ TLCIIN01,0G)