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GEOMIATRIX <br /> petroleum hydrocarbons were reported as detected in soil samples collected from the excavations <br /> associated with the 750-gallon UST One soil bonng was advanced near the 750-gallon UST in 1997 <br /> and no significant concentrations of petroleum hydrocarbons were detected No further investigations <br /> are known to have been performed or are planned for these three former USTs <br /> Additional investigative work associated with the detection of TEPH in samples from the excavated <br /> ' area of the former 10,000-gallon UST was performed subsequently From October 1997 through <br /> June 2004,a total of 18 soil borings(SB-I through SB-6, SB-8, SB-9, SB-10, SB-12, advanced by <br /> ATC Associates, Inc , and HA-1,HA-2,HA-4,HA-6 through HA-9,and TANK-EX,advanced by <br /> Haley&Aldrich,Inc)were advanced in the area of the former 10,000-gallon UST to collect soil <br /> 1 and/or grab groundwater samples for laboratory chemical analysis <br /> Seven(7)groundwater monitoring wells(MW-1 through MW-7)also have been installed at the site <br /> Monitoring wells MW-1 through MW-6 have 20-foot well screens and are screened between depths <br /> of approximately 5 to 28 feet bgs Monitoring well MW-7 is screened across an approximately 30-to <br /> 35-foot depth interval Quarterly groundwater sampling has been performed at the site since 1998 <br /> The most recent groundwater sampling event occurred in August 2004 Groundwater elevation <br /> measurements from the monitoring wells(Table 1)indicate the magnitude of the horizontal hydraulic <br /> gradient at the site to be very low(i e, less than approximately 0 0001 feet per feet)with an apparent <br /> direction toward the south and southwest <br /> The proposed CAP described in this document specifically addresses only the area at and <br /> ' immediately adjacent to the excavation for the former 10,000-gallon UST The areas associated with <br /> the remaining three former UST's are not associated with this CAP because no significant release was <br /> associated with these USTs The term"site"used subsequently throughout the remainder of this <br /> document therefore refers only to the area of the former 10,000-gallon UST and is not to be confused <br /> with the term"site property"which refers to the entire grain terminal <br /> 2.0 SITE CONDITIONS <br /> 1 A discussion of the occurrence and distribution of petroleum hydrocarbon detections reported for soil <br /> and groundwater samples from borings and wells at the site, as summarized in this CAP, are based on <br /> the results of the previous investigations performed by others Reported detections are based on <br /> analyses of total petroleum hydrocarbon(TPH) in either the diesel(TPHd)or gasoline(TPHg)range <br /> ' and for related constituents (e g,BTEX) An evaluation of the potential risks to drinking water, <br /> surface water, and human health from related conditions at the site also is presented below <br /> 1 1Doc_5afe19000s199631CAP\CAP txt doc 2 <br />