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v o A S S D C I A T E 5 1 N C According to Mr Gemelos, the piping associated with these underground tanks was also removed at the time the USTs were removed The inspection report and closure permit do not discuss the removal of the associated piping and samples were not collected from the vicinity of the piping because this was not a requirement of the Local Health District at that time Mr Tom Lutterman of ATC visited the site in September 2000 to perform a site inspection Mr Lutterman observed evidence that the subsurface piping associated with the former USTs was removed The asphalt had been cut away along the pipe pathway from the former USTs to the former dispenser islands and backfilled with concrete as shown in the site photographs taken (Figure 9) No information on soil sample collection in this location has been discovered If soil beneath the piping had been impacted with petroleum hydrocarbons it has likely degraded and does not pose a threat to groundwater as evidenced by the water quality data collected from the monitoring wells subsequently installed at the site (Table 3) 2.0 SUBSURFACE INVESTIGATIONS Further investigation ensued in July 1996, when four soil borings (BI, 132, B3, and B4) were advanced to 15 feet below ground surface by Advanced GeoEnvironmental, Inc Three of the borings were completed as monitoring wells (MW I, MW2, and MW3), the fourth was backfilled with grout to the surface Soil boring and monitoring well locations are shown on Figure 2 Selected soil samples were collected from the borings and submitted for laboratory analysis The analytical results of the samples show that TPHg, BTEX, and MTBE were not detected above their method detection limits in any boring except at monitoring well MW-1 At boring MW 1, at 10 feet below ground surface (bgs), ethylbenzene and xylenes were detected at 0 005 parts per million (ppm) and 0 007 ppm, respectively (Table 2) Total petroleum hydrocarbons as gasoline (TPHg) were not detected in any of the samples The five-foot samples, representing conditions at the capillary fringe, taken at B-1, MW-I, and MW-3 did not contain any detectable concentrations of TPHg, BTEX, or MTBE Apparently notations by Advanced GeoEnvironmental, Inc indicated that a strong hydrocarbon odor was detected in borings B-1, B-2, and B-4 at 7 and 10 foot depths PHS/EHD has concerns that these samples were not analyzed Most of these samples were not analyzed because they were collected from below the water table Groundwater was reportedly encountered at 6 feet below ground surface The one sample that was analyzed only had trace concentrations of ethylbenzene and xylenes as previously described The results of groundwater samples collected and analyzed on a repeatable basis since that time are more accurate and representative of site conditions than one-time saturated soil sample analytical results Soil analytical results are included in Table 2 and copies of boring logs are included in Attachment 3 A cross section showing sample locations and depth to water in each boring is presented on Figure 4 W 192054 00021closure-addendum doc 2