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_ m EM 4.1 Initial. Groundwater Sam le Analytical Results As was stated previously, the groundwater samples collected from the monitoring well installed through the former location of tank T-2 at the 100 W. Valpico Road facility were analyzed for total petroleum hydrocarbons (TPH) and for BTX&E compounds. For the 'nitial roundwater sample collected on April 2, 1990, no TPH concentrations were detected. For the BTX&E compounds, toluene was detected at 0.87 ug/L and xylene (total) was detected at 0.97 ug/L. The concentrations detected were well below the published maximum contaminant levels (MCL's) for drinking water for both compounds (100 ug/L for toluene and 1,750 ug/L for xylene [total]) . 4.2 Confirmation Groundwater Sample-Analytical Results In order to confirm the analytical results from the initial groundwater sample, aonfirma Ton sam a was collected on May 2, 1990. This sample was analyzed for both TPH and BTX&E compounds. No compounds analyzed ford were detected in the confirmation groundwater sample. 5.0 conclusions and Recommendations Through the installation and sampling of a groundwater monitoring well at the former Laura Scudder's facility in Tracy, California, information was obtained which revealed the lack of petroleum related compounds beneath the former location of tank T-2. The lack of these compounds in both the soils and groundwater indicates that no residual petroleum related compounds are present and that - the .former tank removal sites should be granted clean .closure in accordance with the California Water Resources Control Board's Pilot Program. 6.0 Additional Information Upon receipt of the initial sample analytical results, the EHD raised a question regarding the analytical detection limit utilized for the TPH analysis of the groundwater samples. This detection limit, 0.5 mg/L, was not in compliance with the minimum recommended M detection limit as established in the "Tri-Regional Recommenda•- tions° of 0.05 mg/L. As is stipulated in the Tri-Regional recommendations, when a -" recommended detection limit is not achievable, sufficient justifi- cation should be provided. This justification from WESTON Analytics is provided in Appendix C.