Laserfiche WebLink
0 0 <br /> James L. Tjosvold, P.E. <br /> August 19, 1996 <br /> Page 5 <br /> Comment: <br /> 4. All nine of the Federal criteria must be used in evaluating remedial action alternatives in <br /> the FS. Section 8.2 of the FS identifies these nine criteria, and proposes to address the <br /> remaining two once the public community and supporting agency have reviewed the FS and <br /> draft RAP. Section 8 of the FS must include application of the State acceptance criteria and <br /> public acceptance in the evaluation of alternatives. <br /> Response: <br /> 4. Section 8 of the combined soil and groundwater FS will include application of all <br /> nine Federal criteria, including the State acceptance criteria and public acceptance in <br /> the evaluation of alternatives. <br /> Comment: <br /> 5. A supplemental soil investigation was conducted to provide additional characterization at <br /> areas where elevated levels of contaminants were detected in previous investigations, and in <br /> areas where data had not been collected. Section 3.1.3 of the FS indicates results obtained <br /> from the field screening analyses did not correlate well with laboratory analytical results. <br /> Consequently, the FS only uses the laboratory results which consists of approximately 50 <br /> of all the supplemental soil samples collected. DTSC is concerned that the use of only 50% of <br /> soil supplemental sample results has resulted in data gaps remaining and thus the sampling <br /> objective not being met. Please provide a discission on the supplemental sampling results <br /> including an evaluation of results, identification of data gaps, and applicability of results. <br /> Response: <br /> 5. The objective of the supplemental soil investigation was to further characterize <br /> the extent and nature of MGP and underground tank residues in identified source <br /> areas for the purpose of providing information needed to develop and evaluate <br /> potential remedial alternatives. This objective was met as soil borings were drilled <br /> and sampled within, immediately outside and in between the four identified source <br /> areas. Residues and other information observed with depth were logged for each <br /> soil boring. Three more borings were drilled than planned to confirm the outside <br /> extent of some of the former MGP structures. Additional samples were sent for <br /> laboratory analysis than planned as described below. <br /> As discussed in the workplan for the Supplemental Soil Investigation (submitted <br /> June 12, 1995), the field analytical measurements (Hanby kits) were used to analyze <br /> the samples collected from each soil boring. The field test kit results were used to <br /> determine which samples should be sent to the laboratory for confirmation of the <br /> field results. Since the field test kit and laboratory results did not correlate well, the <br /> laboratory results were used in addition to field observations for evaluating the soil <br />