Laserfiche WebLink
1.2 Site Background <br /> On 7 September 1994, stockpile samples SPE and SPW were obtained from the stockpiled <br /> backfill material excavated from the 6,000-gallon diesel UST pit prior to removal of the tank. <br /> The results of analytical testing indicated that soil sample SPE contained 17 parts per million <br /> (ppm) total petroleum hydrocarbons as diesel (TPHd) and soil sample SPW contained 230 ppm <br /> TPHd, 0.016 ppm ethylbenzene, and 0.047 ppm xylenes. <br /> Samples of the native soils at the bottom of the UST pit could not be obtained at the time of the <br /> tank removal due to caving of the backfill gravel surrounding the newly installed 10,000-gallon <br /> UST. The concrete slab at the bottom of the UST pit was not observed at the time of the UST <br /> removal due to caving of the backfill gravel materials. The abandoned UST pit was immediately <br /> backfilled with the excavated gravel material to avoid damage or rupture of the adjacent 10,000- <br /> gallon UST. <br /> 1.3 Scope of Work <br /> The purpose of the soil investigation was to determine whether diesel fuel has affected the native <br /> soils surrounding the abandoned 6,000-gallon UST pit. Except for the number and exact <br /> placement of the soil boreholes (as noted in section 2.2), the soil investigation was conducted <br /> in accordance with the RES work plan dated 27 September 1994. A copy of the work plan for <br /> the underground storage tank investigation is provided as Appendix A. <br /> The scope of the UST investigation included the following: <br /> 1) Preparation of a UST investigation work plan and submission of the work plan to the San <br /> Joaquin County Public Health Services, Environmental Health Division (SJCPHS) for <br /> review and approval. <br /> 2) Acquisition of the necessary soil boring permit and scheduling of the borehole grouting <br /> inspection through the SJCPHS. <br /> 3) Exploratory boring in the native soils surrounding and beneath the abandoned UST pit <br /> using a truck mounted hollow stem auger drill rig. <br /> 4) Acquisition of samples of the native soils encountered in each of the boreholes at a depth <br /> corresponding to the bottom of the concrete slab. <br /> 5) Analysis of soil samples for TPH as diesel and the fuel components benzene, toluene, <br /> ethylbenzene, and xylenes (BTEX). <br /> 6) Preparation of this Soil Investigation report. <br /> r <br /> 4185\CBW4\SPR11W.RPTV0CP94 2 <br /> v <br />