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t .Y' <br /> Mr. Harlin Knoll Project No. 2007-065-01 <br /> May 19, 2000 <br /> Page 4 <br /> Monitoring Well Development and Sampling <br /> On May 16, 2000 the two monitoring wells were developed using a combination of <br /> bailing, pumping, and surging methods. The monitoring wells were sampled on the same <br /> day (approximately 12 hours after development). Purge water generated during <br /> development and sampling was placed in DOT 55-gallon drums and stored onsite. <br /> Groundwater monitoring well development procedures are presented in Appendix D. <br /> The groundwater levels in each monitoring well were also measured using an electronic <br /> sounding device, and recorded on the monitoring well data form presented in Appendix <br /> E. <br /> RESULTS OF INVESTIGATION <br /> Site Geology <br /> The upper 3-5 feet of soil appears to be fill material engineered for construction purposes. <br /> Sand is present from 5-20 feet bgs in both MW-9 and MW-10 and from 11-20 feet bgs in <br /> AS-1. A silt and clay layer is present at 21 feet in all three borings and from 25 to 26 feet <br /> in MW-9. Sands of variable grain sizes are present beneath a silt and clay Iayer in all <br /> three borings from approximately 25 to 35 feet bgs. This sand layer is approximately ten <br /> feet thick in each well and appears to be continuous beneath the site, with an undulatory <br /> contact with the overlying silt and clay layer. From 35 to 50 feet bgs, no correlations <br /> between borings can be made. Thin, discontinuous layers of sand and silt appear to be <br /> present from 35 to 50 feet bgs. Groundwater is encountered at approximately 40 ft. bgs. <br /> Based on historical groundwater data, depth to groundwater fluctuates between 38 and 53 <br /> feet bgs. <br /> Analytical Results <br /> Soil samples collected from each soil boring and the soil sample collected from the <br /> drummed drill cuttings were submitted to Alpha Analytical, Inc. in Sparks, Nevada, a <br /> California state certified analytical laboratory. Groundwater samples from the two <br /> monitoring wells were also submitted to Alpha Analytical. The samples were submitted <br /> with the appropriate chain-of-custody documentation. <br /> The samples were analyzed for total petroleum hydrocarbons/purgeable and volatile <br /> organic compounds as gasoline (TPHG), BTEX, and five oxygenates (MTBE, TAME, <br /> TBA, DIPE, and ETBE), using EPA Method 8015B/DHS LUFT and EPA Method 8260B <br /> respectively. <br /> Petroleum hydrocarbons (TPHG and BTEX), and all five oxygenates were reported <br /> below method detection limits for all soil samples analyzed, from the two borings west <br /> CAMy Documents\UW651report.doc Stratus <br />