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• <br /> Review of the Draft Project Closeout Plan (Remedial Action Report), <br /> SWMU 8 Large Excavation,DDJC-Tracy Site, Tracy, California <br /> April 2004 <br /> GENERAL COMMENT <br /> 1. The decision to completely backfill the SWMU 8 excavation is not documented correctly. <br /> The text in Section 3.2.7.3 states that the Remedial Project Manager(RPM)team met on <br /> November 19, 2002 and determined that remedial excavation activities were sufficiently <br /> complete and backfilling should proceed. However, the DDJC-Tracy RPM Meeting <br /> Minutes from November 19, 2002 state in several places that Shaw was requesting to <br /> backfill the'northem part of the excavation, backfilling only the deepest areas from 14 to <br /> 20 feet below ground surface (bgs). The plan was to continue to excavate evidence of <br /> contamination on the benches, estimated at an additional two vertical feet. EPA stated <br /> that it wanted to describe the exceedences that were proposed to be left in place in the <br /> center trench below 14 feet bgs to EPA management and get concurrence to allow the <br /> backfill of the center trench. A conference call for November 25, 2002 was supposed to <br /> be set up by Shaw to discuss the data further and receive EPA management's response on <br /> backfilling. Based on the meeting minutes, it was clear that further excavation and <br /> confirmation sampling were going to occur, and that though EPA could not approve <br /> backfill, the risk to the contractor was very small if backfilling below 14 feet bgs <br /> occurred. The text in Section 3.2.7.3 states that after the RPM meeting, a visit to SWMU <br /> 8 occurred and it was "inferred" that there was apparently no end to the low level <br /> detections of pesticides. The entire excavation was then backfilled beginning on <br /> November 21, 2002. There appears to be no documentation regarding any decisions <br /> made during the site visit after the RPM meeting. For example, the field notes in <br /> Appendix C from the site visit do not document any discussion of backfilling. It is <br /> unclear what decisions were made during the site visit, who approved these decisions, <br /> and why these decisions were not documented. It appears more likely that the excavation <br /> beyond the center trench was backfilled without approval. Please provide a more detailed <br /> discussion on the decision to backfill and provide (or reference) all supporting <br /> documentation showing RPM approval of these decisions. In addition, please remove the <br /> statement that the "RPM team met and determined that remedial excavation activities <br /> were sufficiently complete and backfilling should proceed" from the text since this is <br /> misleading, or qualify it to note that approval was given for backfilling the center trench <br /> below 14 feet bgs only. <br /> SPECIFIC COMMENTS <br /> 1. Section 2.2,Page 2-1,third bullet: The text states that the Record of Decision (ROD) <br /> requirement to collect soil gas samples was eliminated, but no documentation is <br /> 1 <br />