ARCHIVED REPORTS_XR0012624 - Laserfiche WebLink

Home Browse Search

I 1 i I i 3 The ends of brass tubes containing soil samples for laboratory :.. analysis were covered with Teflon film and plastic caps to provide an i air tight seal. Each sample tube was appropriately marked on site E with the boring number, sample designation, date, time, and depth. Samples were placed on ice in a cooler and transported to a Aniab to Analytical Laboratories for analysis. Anlab is a State-of-California i certified laboratory located in Sacramento. # As a standard procedure, Chain-of-Custody forms were completed at t ; the time of sampling and accompanied the samples to the laboratory. Copies of the Chain-of Custody forms are shown in Appendix D. ! Soils in the upper 10 feet were characterized as £ill material usel to E backfill the excavation left by the removal of the tanks. This n.a!erial consisted of rubble and gravel in a soil matrix of clayey sands. ° Underlying the fill material is a silty clay which extended in most borings to 25 or 30 feet below the ground surface. The silty clay was slightly moist to dry with a strong platy structure. One gravel lense and other lenses of medium to coarse smad were found in the silty clay below 30 feet. I I ' 7 The soil cuttiisgs from the borings were placed in three labeled 55- gallon drums pending completion of laboratory analyses. Following receipt of the analytical results, the cuttings were taken to Casmalia Resources for disposal by Erickson, Inc. A copy of the manifest for the drummed cuttings is in Appendix E. The bore holes were 4 -- backfilled with fznrefined bentonite to approximately 3 feet below grade. Grout was used to fill the remaining 3 feet to grade. The components and ratios of the grout mix were discussed and agreed ; upon with a representative from the San Joaquin County Public Health Services who was present on the site. All samples were analyzed for Total Petroleum Hydrocarbons by EPA T Method 8015 modified. Results of the sample analyses are summarized in Table 1-2. Laboratory reports are shown in. Appendix i F. Petroleum hydroca:pons were detected in all soil borings except i x Borings 1, 2, and 8. All detections were characterized as diesel. With only two exceptions (Borings 6 and 10), soil contaminat. )n was 3 confined to a zone around the bottom of the former excavat.on. A clean bottom-of-the-hole sample was obtained in all borings except 3 i-9 RINDS-111.1 rampl-IINEEKI gloom i