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4.1 Groundwater Results The groundwater analytical results from tlhe September 27 and October 22 sampling confirm that there are no detectable concentrations of BTEX, T131H-G or total lead in groundwater in MW-4. These analyses are consistent with previous analytical results froihh MW-4 and the other three monitor wells on the site and further support WESTON's interpretation that the groundwater in MW-4 has not been impacted by petroleum hydrocarbons. In summary, groundwater analytical results for the two most critical wells onsite (MW-I Incated directly over the former tank site and MW-4, located dolvngradiert from the former tank site) have consistently shown no detectable hydrocarbon presence. Table 2 presents the analytical results from these wells since the first sampling event in March 1991. Based on these data from repeated groundwater sampling onsite, WESTON suggests that there is abundant and conclusive evidence that hydrocarbon compounds have not impacted groundwater beneath the site. TABLE2 MW-4 and MNV-1 Groundwater Analytical Results Well Sample h,'A 602 pg/L (ppb) EPA 9015 mg/L (ppm) EPA 239.2 mg/L (ppm) F.D. Date detection limit:•0.50 detection limit: 20 detection limit: 0.005 Benzene Toluene Ethyl. Xylene TPH-G Total Lead benzcne MW-1 03/0,9/91 NU ND ND ND ND 0.0082 MW-1 04/11/91 ND ND ND ND ND Not Analyzed (NA) by permission of EHD MW-4 07/10/91 ND ND I ND ND I ND NA MW-4 07/16/91 ND ND ND ND ND NA ROW-4 09/27/91 ND ND ND ND ND NA MW-4 10/22/91 NA' NA NA NA NA ND (Method 7421) I. ND = Non defected at a conceniriiior: cr,_ater than lkh'; CiPorting limit. 2. NA = Not analyzed. 4.2 Toluene in a Previous Soil Sample SB-1 In the September 17, 1991 letter to Souza Realty, the EHD requested an explanation for'the love `eN,el soil contamination in and possibly near soil boring #3." As reported in the "Addcndum to Problem Assessment Report" dated August 19, 1991, there was no toluene found :n SB-3. There was, ho%vever, it concentration of 0.03 mg/Kg of toluene found in soil wanhple .�B-1.