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Quik Stop Market No. 132 July 11, 1991 Project No. 3-49132-31 Page 2 these borings showed little or no petroleum hydrocarbon contamination. Analysis of groundwater samples collected from monitoring wells MW-3 and MW-4 revealed no petroleum hydrocarbon related contaminants. Analysis of groundwater samples from backfilled MW-2 detected 1 ppb benzene and detectable levels of ethyl benzene and totzl xylenes. Groundwater monitoring well MW-1 was destroyed by Exceltech on October 3, 1990, due to concerns that it could connect two water-bearing units which appear to represent separate shallow aquifers, This groundwater mor:itoring well was replaced with two groundwater monitoring wells, one to monitor the upper water bearing unit and one to monitor the lower w.er bearing unit. These installations are included in this report. During the above act?vities, a leak was discovered in the subsurface pipipg. Excavations to remove the contaminated soils indicated that the colitamination had affected the tank backfill and possibly the soil beneath the tank backfill. Upon issuance of the proper permits, the overhead canopy, pu'c;p islands concrete surface, and three underground storage tanks (USTs) were removed ip October "d November 1990. Following tank removal, excavation and soil sampling was f;ontinued until laboratory analyses of soil samples indicated that petroleum hyc rocarbon contaminated soil ab--m the water table in the vicinity of the storage tank excavation had been removed. 'Af jd6jif iiiiyiated;Soil was renovci,fraia<tlre.statxst arid":pr�perly dt5ppst he USTs were replaced with new, double-walled fiberglass USTs and the remaining excavation was backfilled with clean fill. The canopy, pumps, and concrete surface were replaced and the station is currently in operation. SCOPE OF WORK The scope of work for this project included: • Review of previous investigations at the site; • coordination and permitting with proper regulatory agencies; • drilling of two exploratory borings, soil sampling for laboratory analyses, and logging of the boreholes; • conversion of these boreholes to properly-constructed groundwater monitoring wells,, • development and sampling for laboratory analysis of the three groundwater monitoring wells;