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07 May 2002
<br /> AGE-NC Project No. 98-0466
<br /> Page 9 of 16
<br /> known of the dioxins and furans is the tetrachlorinated dioxin 2,3,7,8-1 DD, considered the most
<br /> potent animal carcinogen and reproductive toxin evaluated to date by the EPA. In addition,there are
<br /> 16 less toxic chlorinated dibenzodioxins (CCD) or chlorinated dibe ofurans (CDF). They are
<br /> referred to as 2,3,7,8-substituted congeners. When mixtures of dioxins d furans are present in a
<br /> sample a Toxicity Equivalent (TEQ) is calculated to express the toxicit of the mixture. The TEQ
<br /> is determined by multiplying the congener concentrations by its respective Toxicity Equivalency
<br /> Factor(TEF) and summing the TEF concentrations. Soil with TEQ concentrations below one part
<br /> per billion (ppb) would not be considered an environmental hazard and could qualify for land
<br /> disposal, unless considered hazardous for other reasons. In addition tote TEF, the percentage of
<br /> the TEQ attributed to 2,3,7,8-TCDD should be considered when assessing the risk associated with
<br /> contamination.
<br /> Results of the dioxin analyses show that the TEQ threshold was not xceeded in any of the six
<br /> samples analyzed. The TEQs for composite sample 1 (SP4-6, SP7-6, Sf 12-4, SP14-6), composite
<br /> sample 2 (SP19-6, SP17-4, 5P16-2) and composite sample 3 (SP10-4,D 10-5)were 242.315 parts
<br /> per trillion(ppt),43.695 ppt and 47.064 ppt,respectively. The TEQs for individual samples SP 12-5,
<br /> SP14-7, SP7-7 and SP4-7 were 9.149 ppt, 7.624 ppt, 433.59 ppt, and 295.94 ppt, respectively.
<br /> Samples SP12-5 and SP14-7 did not contain 2,3,7,8-TCDD at concentrations above laboratory
<br /> reporting limits. Percentages of the TEQ contributed by 2,3,7,8-TCDD in the remaining samples
<br /> ranged from 2.52% to 28.5%. Analytical results of dioxin analysis was summarized in AGE's Site
<br /> Environmental History, dated 04 May 2001.
<br /> In addition to dioxin analyses, selected samples collected in June 2000 Were analyzed for lead and
<br /> pH. Results of the analyses show that the total lead content is above background levels but are not
<br /> high enough to classify the soil as hazardous waste for total lead. Four ampler were analyzed for
<br /> soluble lead due to higher elevated total lead concentrations (SP3-2A, S 4-6A, SP7-6A and SP14-
<br /> IA) and were found to contain soluble lead concentrations ranging from 0.02 mg/1 to 0.18 mg/l.
<br /> These concentrations do not exceed the STLC of 5 mg/l. Values of pH ar at levels considered to be
<br /> background, ranging from 8.15 to 9.15.
<br /> During the December 2000 site investigation, a ground water sample collected from boring SBP-1
<br /> did not contain detectable concentrations of TRPH, formaldehyde, TCE,TCP,PCP or VOCs. Total
<br /> chromium was detected in the ground water sample at a concentration of 0.30 mg/1, lead was
<br /> detected at 0.03 mg/1, copper,nickel and zinc were detected at concentrat ons of 0.24 mg/1,0.27 mg/1
<br /> and 0.36 mg/1. The sample was not filtered prior to analysis, so the metals results include total metals
<br /> from entrained mineral grains and are not representative of dissolved metals concentrations.
<br /> AGE proposes to collect up to 20 additional soil samples from the soil stockpiles to assess for
<br /> various metals for waste classification and potential treatment requirem mts.
<br /> Advanced GeoEnvironmental,Inc.
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