ARCHIVED REPORTS_XR0007169 - Laserfiche WebLink

Home Browse Search

feet bgs to <1 ppm in all soil samples collected below 55 feet bas (see borehole log, Appendix B). • The augers and sampling equipment were steam cleaned prior to drilling the boring and the sampling equipment was washed with a TSP solution and rinsed in clean water between each sampling interval. LITHOLOGY OF SOIL. SAMPLES During the drilling and sampling operations the WEGE geologist maintained a log of the materials encountered (see Appendix B). The top 26 of section consisted of medium brown silty clay, and stiff dry clay with occasional strong petroleum odor beginning at 20 feet below ground surface (bgs). A six foot layer of medium grained sand containing smaller lenses of silt and clay was encountered between 20 and 26 feet bgs. A color change from medium brown sediments to greenish gray occurs at 26 feet bgs. The section from 26 feet to 48 feet consists of a stiff greenish clay with some petroleum odor that grades downward to clay with silt. The section from 48 feet to the base of the soil boring at 80 feet bgs consists of a greenish gray to dark gray silt and clay with fine to very fine sand layers occurring at 52.5-56 feet bgs, 60-64 feet bgs and 78-80 feet bgs. No petroleum odor was noted in any of the samples collected below 50 feet_ PRESERVATION OF SOIL SAMPLES The ends of the brass sleeves containing the soil samples were sealed with a Teflon film and further protected with plastic caps. Each sleeve was labeled with site name, date, time, sample location, and analyses to be performed. Each labeled soil sample was placed in a separate zip lock bag, deposited in and ice chest, and cooled to 4'C. The soil samples and accompanying chain of custody documentation were delivered to Kiff Analytical Laboratories (DHS# 2236), on December 13, 2000. COLLECTION OF GROUNDWATER SAMPLES FROM S—BI- Three 1Three groundwater samples were collected during the drilling of TH1 using "hydropunch" techniques. The water samples were collected from the two foot screened interval of the hydropunch tool at the depths of 60-62 feet bgs, 70-72 feet bgs, and 80-82 feet bgs. The auger and bit were advanced to three feet above the top of the desired sampling interval at which point a hydropunch tip and screen was inserted through the hollow stem auger at the end of a hollow rod and driven five feet into the formation at the base of the test hole. The covering of the screened interval of the hydropunch tool was then retracted two feet to allow groundwater to enter the tool. Groundwater samples were collected from the screened tip of the hydropunch tool with a mini bailer through the hollow rod. The water samples were decanted into 4 VOA vials with no airspace and preserved with 0.5 ml of HCL. The water samples were labeled and preserved as described above for the soil samples. ARC SRPT 312101 3