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r, t`- d s �r 311 1 peaks which fall outside the range of BTEX. SOIL REMEDIATION-OVEREXCAVATION As stated in earlier reports, the tank excavation was extended to the 25 toot death and samples were taken at that time, Jruiie 26, . 1990. All the samples were "non' detect', less than 10 ppm, for Total Petroleum Hydrocarbons (TPH) . Minor amounts of toluene, ®fl ethylbenzene, and xylenes shoved up in the sample taken from the center of the excavation EX-5 and minor amounts of xylenes showed up in the samples taken at the southeastern edge of the excavation EX-A and EX-B. The vapor extraction well EX was drilled and sampled on October 9, 1990, and showed 2 ppm gasoline range hydrocarbons at the 30 and 37 foot depth wi�.:h the BTEX's being below detection limits for these samples. The soil analysis from the nlacement of the two additional monitor wells (MW5 and MW6) were all below detection limits for TPH and BTEX with the exception of the sample obtained from MW5 at the true vertical depth of 33 feet, which had minor amounts of toluene and xylenes, see Figure 3B. Excavation of the pump island area,comnenced.on'August 16, .1990. Using Hanley and Sons backhoe and operator, three trenches were cut to the six foot depth through each of the three island areas, paralleling Harding Way. The excavated soil from these cuts were screened by a WEGE geologist for odor and with a HNU photoionizing detector (PSD) . The trenches were advanced until no odor. or detectable readings were found in an east-west direction. Once ..the contaminated soil was delineated in these trenched. areas, excavating was performed i1i a north and south direction to the thirteen foot depth. Samples obtained from the base of the middle island area indicate that the excavation was successful in removing the contaminated soil from this area. To enable the backhoe to proceed deeper, ramps were constructed into the west and east pump island areas. The excavations of the -western. and _ eastern pump islands were then deepened to the twenty foot depth. Samples obtained from the base of these two excavations show that contaminated soil still exists beneath the 20 foot depth, see Figure 3B. On October 8, 1990 vapor extraction wells P1 and P3 were sampled and installed at the eastern and western pump island excavations respectively. Soil sample results obtained from the 30 and 40 foot depth of P1 show 2 ppm gasoline range hydrocarbons with minor amounts of BTEX's. Soil sample results from P3 show 12 ppm gasoline range hydrocarbons at the 25 foot depth and 2 ppm -- — -- -------gasoline-range-hydrocarbons-at--the--30-and 40-foot--depths-' BTEX�s - are above detection limits in the 25 and 30 foot samples, but Below detection limits in the 40 foot depth sample. All samples were preserved, labeled, and chain of custody hand delivered to Chemtech Laboratories for analysis using EPA methods 8015 and 8020. page 5