Laserfiche WebLink
Mr. Hank Gonzales <br /> October 8, 1992 <br /> Page 3 <br /> The remainder of the soil in the middle and upper brass tubes and in the sampler <br /> shoe (and, as appropriate, drill cutting soils) was used to complete the drilling logs <br /> (see Appendix A). The logs include PID readings, sample numbers, lithologic <br /> descriptions (completed in accordance with the Unified Soil Classification System <br /> [USCS]), sampled intervals, blow counts, equipment used, sampling dates, and <br /> borehole abandonment details. <br /> After sampling was complete, the borings were backgrouted to the surface with neat <br /> cement slurry containing approximately 5%to 10%bentonite.The grouting operation <br /> was inspected by Mr. Steven Schneider (a Senior Registered Environmental Health <br /> Specialist with San Joaquin Public Health Services, Environmental Health Division). <br /> Soil cuttings from each borehole were placed on the ground after each boring was <br /> completed and no field indications of petroleum hydrocarbons were found. <br /> FIELD SCREENING AND ANALYTICAL RESULTS <br /> Lithologic units encountered during drilling of the soil borings consisted of silty sands <br /> and fine-grained sands. These soil units are represented by the USCS symbols SM <br /> and SP, respectively. Moisture content in the soil borings ranged from very dry to <br /> moist. Saturated soil conditions were not encountered in either of the borings. No <br /> soil discoloration or petroleum odors were detected during sample collection. <br /> Headspace readings showed 53 parts per million (ppm) VOCs in all samples <br /> measured. Headspace readings at these levels are not considered indicative of diesel <br /> occurrence because readings of up to several ppm (using a PID) are commonly <br /> associated with moisture in soils. <br /> One soil sample (collected from SB-2 at a depth of 15.5 to 16 feet) was analyzed for <br /> total petroleum hydrocarbons (TPH) by EPA Method 8015 (Modified). This soil <br /> sample was selected for laboratory analysis because it was obtained from near the <br /> end of the tank where the associated supply, return and fill pipe risers emerged from <br /> the ground and where diesel-affected soil would most likely be encountered if the <br /> tank had leaked or if spills had occurred during tank filling operations. <br /> The analytical result showed no detectable petroleum hydrocarbons in the soil <br /> sample collected from boring SB-2 at the laboratory reporting limit of 10 ppm (see <br /> Appendix B for laboratory quality control documentation, chain-of-custody forms and <br /> analytical data sheets). <br /> c arcn <br /> . art <br />