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On June 6, 1993, monitoring well MW-3 was purged and sampled On July 6, 1993, all three monitoring wells were sampled No contamination was detected in these samples On 12 July 1993, sic samples were collected from the stockpiled soil and analyzed for TPH as gasoline and BTE&X Low to moderate concentrations of TPH as gasoline were detected in five of six samples from the stockpiled soil The results of the overexcavation procedures, groundwater sampling and stockpile sampling were reported in the Site Assessment and Groundwater Sampling Report submitted by GeoAudit in August 1993 2.5 Sol] Remediation Two methods of soil remediation were considered at this site The fust method, transportation and disposal is generally the fastest method of soil remediation However, it is generally very expensive Furthermore, future liability remains with the generator Ex-situ bioremediation involves the application of hydrocarbon-degrading bacteria to the contaminated soil This method is comparatively inexpensive, has no associated long-term liability However, depending upon the quantity of soil and concentration of contaminants, ex-situ bioremediation can be somewhat of a slow process ` 3.0 PROCEDURES Ex-situ bioiemediation was chosen to treat the contaminated soil at the site The soil was placed in a treatment cell and hydrocarbon-consuming bacteria were sprayed on the ' contaminated soil 3.1 Treatment Cell Creation On September 10, 1993, a backhoe was used to create a treatment cell for the application of bacteria to the contaminated soil Approximately 125 cubic yards of contaminated soil ' were placed on plastic sheeting The soil was spread to a depth of 2 5 to 3 feet and water was sprayed on the soil to maintain moisture content of 5 to 10% The soil was then covered with plastic sheeting ' 3.2 Treatment Cell Inoculation ' On September 14, 1993, the treatment cell was inoculated with hydrocarbon-consuming microbes The plastic sheeting cover was removed and approximately 50 gallons of microbial broth were applied to the cell by representatives of GeoAudit and WACO Environmental ' The bacteria are grown in a growth media for 48 hours, and the resulting bacterial culture is used as the inoculum At the time of inoculation, the growth media has been spent, ' having been converted into biomass. The inoculum is called a cream because most of the G-i"—1 Audi S.rvu..M. ' Quawly RcpGrV12 9WJ S