SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

Page 2, 1645 Cherokee %POO sod No map was provided that shows the locations of samples EW-3 through EW-40, EW-70 and EW-80 (Table 3, Remedial Confirmation Sampling Results); DPWW-80, DPNW-82, NW-60 and NW-70 (Table 4, Remedial Confirmation Sampling Results); NW-30 through NW-65, EW-35, EW-40, WW-15 through WW-40 and WW-60 through WW-75 (Table 5, Remedial Confirmation Sampling Results); or DPWW-8.A, EW-5.A, WW-70.A, NW-70.A and EW-25.A (Table 6, Final Remedial Confirmation Sampling Results). Map Sheet 6 and Map Sheet 10 both indicate plotted locations for samples labeled WWCSF-62, WWCSF-72 and WWCSF-78, but show them in very different locations and in different relative relationship to each other. Similarly, Map Sheet 5 and Map Sheet 10 both indicate plotted locations for samples labeled WF-50, WF-55 and NF-49, but show them in different locations and in different relative relationship to each other. The data tables provided in the report are also not clear. Soil sample EW-45 is listed on Table 1 with a sample collection date of 8/30/05, on Table 3 with a sample collection date of 9/29/05 and on Table 5 with a sample collection date of 10/4/05. Sample WW-50 is listed on Table 1 with a sample collection date of 8/30/05 and on Table 5 with a sample collection date of 10/4/05. Samples EW-35 and EW-40 are listed on Table 3 with.a sample collection date of 9/29/05 and on Table 5 with a sample collection date of 10/4/05. If in fact confirmation samples collected on different days were given the same names, this should be clearly stated and a method of distinguishing them from each other on the excavation maps must be provided. Evaluation of soil contamination remaining at the site is problematical without correct and accurate maps. Data tables indicate the confirmation soil samples were collected to depths ranging from 3 to 84 feet bsg. Most soil samples appear to be called 'wall samples', which could indicate the surface from which they were collected is still in place at the site. However, with so many samples apparently given the same name, where they came from or whether that surface still exists at the site is not clear_ No sample data was provided from any soil that was excavated and stockpiled onsite prior to removal. The deepest soil samples collected from different sides of the excavation appear to range in depth from 75 feet bsg on.the south wall to 84 feet bsg on the north wall. The south wall sample DPSW-75 was positive for petroleum hydrocarbons, as were the two deepest samples from the west wall, WWCSF-78 and DPWW-80. East wall sample E-80 was non-detect for petroleum hydrocarbons. North wall sample NWCSF-84 was non-detect for petroleum hydrocarbons. Sample DPNW-82 was positive for petroleum hydrocarbons but its location is unknown. The sample name would indicate it was on the north wall, but the table says it was located on the west wall and it was not plotted on any map. One grab groundwater sample, W-1, was collected from the excavation. It was collected at 75 feet bsg on the west wall, and was positive for total petroleum hydrocarbons as diesel. You are directed to submit corrected and/or clarified data tables, and revised maps of the excavation with all sample locations identified and successive excavation margins shown. Clearly state, if true, which impacted soil sample areas were removed by subsequent excavation, note which impacted samples locations were left in the final excavation and illustrate those sample locations on a final excavation map. Submit these materials to SJC/EHD no later than July 6, 2007.