FIELD DOCUMENTS - Laserfiche WebLink

Home Browse Search

samples, the borings were extended to depth of 14 feet. A 3/4-inch-diameter, flush-threaded, Schedule 40 PVC casing with 0.010-inch slotted screen was inserted into each boring to the total depth. Construction details for the temporary wells are included in the boring logs presented in Appendix C. Before collecting water samples,each temporary well was purged of approximately 5 gallons of water while monitoring pH, specific conductivity, and temperature to demonstrate that the sample was representative of the water-bearing zone. The temporary wells were purged and groundwater samples were collected using a peristaltic pump with new sample tubing used for each sample collection. The samples were transported in an iced cooler to a state-certified laboratory following chain of custody procedures. After collection of groundwater samples, the borings were backfilled with neat cement as the casing was removed from the ground. Field procedures for temporary well installation and sampling are presented in Appendix B. The groundwater sampling and field survey forms are included in Appendix D. 3.0 ANALYTICAL METHODS Soil and groundwater samples were analyzed for petroleum hydrocarbons by Argon Laboratories, Inc., a state-certified laboratory, using standard test methods recommended by the RWQCB and the U.S. Environmental Protection Agency (EPA). Each soil sample was analyzed for the following: • Total petroleum hydrocarbons in the gasoline range (TPH-G),generally C4 to C12,using EPA Methods 5030,Modified 8015, and 8020 or 602 • Total petroleum hydrocarbons in the kerosene range (TPH-K), generally C8 to C13, using EPA Methods 3550 or 3510 and Modified 8015 • Total petroleum hydrocarbons in the diesel range (TPH-D), generally C10 to C20, using EPA Methods 3550 or 3510 and Modified 8015 • Total petroleum hydrocarbons in the motor oil range (TPH-MO), generally C20 to C42, using EPA Methods 3550 or 3510 and Modified 8015 • Aromatic hydrocarbons as benzene, toluene, ethylbenzene, and total xylenes (BTEX) using EPA Methods 5030 and 8020 The results of the soil and groundwater sample analyses are summarized in Tables 1 and 2, and the laboratory reports are included in Appendix E. 4.0 RESULTS AND FINDINGS The results and findings of the June 27 and 28, 2002 soil and groundwater sampling and analysis are summarized below. • Analysis of soil samples collected from Borings SB-7 through SB-13 at 3, 6 and 9 feet below grade only detected toluene in 11 of the 20 samples at concentrations ranging from 0.005 E\02\111211\211-15\reportdoc 3 .