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111 14•December.2003 r:• , , 'AGE NC'Project No 98 0504 ,+ 1 Page 2 of 5. a w y Ir - r c Ft 2 3 UNDERGROUND:STORAGE TANK.REMOVAL '1 1 Two'-USTs',-dispenser island and associated piping were.removed"fromahe site,orr 22 September,: 199$. Four-,samples''rwere,collected.beneath -the=USTs; one sample was"collected..beneath the ' dispenser area and three laboratory-'Composited'soil samples were collected from the excavated soil ' Methyl.tertiary butyl ether (MTBE) .and tertiary butanol'(TBA) were:detected in,..'Boll samples` ` ' collected from-beneath the USTs and dispenser island at concentrations"u -to 39 parts per million" (ppm);total petroleum hydrocarbons quantified'as gasoline(TPH=g)were detected at concentrations :, ' ' up to,1,400 ppm;and'volatile aromatics(benzene;toluene,'ethyi benzene:and xylenes:BTEX)were detected at concentrations up to 190 ppm.' Approximately 200 tons�of soil were excavated duringlremoval of the USTs. After removal of the ' h drocarbon"-�` USTs was'completed; soll•was,placed back mto.the excavation because of strong y , odors and the proximity to a school. Two laboratory-composited"samples were collected from the stockpiled.soil prior to placement into the excavation.TPH-g,BTEX and MTBE and TBA were all detected'in the composite samples. 2.4..' ..SOIL EXCAVATION.PROCEDURES. 1 ' On 10 November 1998,. ' proximately 250 yards of hydrocarbon-impacted soil were excavated from 5� the location of the former UST system. Soil was excavated usirig'a backhoe with'an approximate 15=foot reach capability. Excavated.soil was. field-screened'for.the 'presence-of volatile organic 1 compounds using an"OVM."Soil was stockpiled"on the eastern edge of the site. Approximately 150- - yards ofsoil"was loaded and transported to Forward Inc.Landfill under'manifest for proper disposal on'l0 November 1990. An additional 100 yards of impacted soil were transported to Forward Inc: Landfill for disposal on 14 December 1'999.' Soil samples collected from the floor and sidewalls of the excavatioriwere obtained using abackhoe. A'total'of nine soil samples were collected from the floor arid sidewalls of the over-excavatlon. . TPH-g was detected at'concentrations up,to 80 milligram per kilogram (mg/kg) in the sample from, the north wall' east.erid of the excavation. TPH-g was not detect in soil samples collected from the' south,northwest, and easf wall of the over excavation. Additionally, TPH-g was nondetected in the ; samples collected-frorri the south end of the west wall and'from.the floor of;the excavation. BTEX compounds were detected at concentrations up.to'1.0 mi g/kg;"benzene was only detected in - the north west wall sample. MTBE and TBA were detected at concentrations-up to.IT.3 'mg/kg and 8.9 mg/kg, respectively. MTBE was detected at the highest concentrations in the northern-portion of the over excavation,especially in the northernwest wall sample,located at.the northwest'edge �,. the site under Monroe.Avenue. Analytical results of soil samples are'summarized in Tables hand 2. .� _ i Advanced CeoEnvironmental,Inc. ; "~ 1 ry