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9/30/93 Responses to Comments San Luis Reclamation Evaluation Report Page 20 about accepting the analysis of a single fluid sample to be representative of all fluids in the tailings, both in the vertical and lateral dimensions. BMG should explain why the angering methodology was employed rather than some other more practical one that could have provided some assurance of retrieving saturated sediments from the deeper depths. I think it is unacceptable to eliminate the need for adequate sampling because of difficulties encountered using the sampling methodology. Included in the explanation should be a discussion of the mineralogy of the ore body indicating that tailings in the upper few feet of the tailings pile have the same or similar mineralogy as those in thle deeper depths. In view of the requirements of Abatement 8 that the liquid portions of the tailings be sampled and analysed, BMG should furnish some indication of why this issue has not been properly addressed; that is, why only one sample of liquids was collected. BMG should also explain why they feel that one sample of fluid ""should represent the pore water at depth in tailings deposited with high cyanide concentrations" (p.39). Given the time it takes to collect and analyze the tailings samples, and assuming further sampling will be necessary, BMG should adopt and initiate a sampling methodology that will provide results quickly. Response: it is correct that the holes were terminated due to inability to retrieve a sample and not based on the depth to liner. As discussed in Section 2 of the Preamble, when BMRI initiated the sampling they were constrained by both the deadline for the report and the need for major construction to employ another sampling method using mechanical equipment. The angering method was attempted first to determine how effectively the tailings material could be sampled. There are several incorrect conclusion drawn in the statement above. First, as discussed in a previous response, there is no "standing water tables' in the tailings material. Therefore, a statement that "most of the wells barely reached the pond water level" is incorrect. Secondly, although none of the auger holes in the lower area came within five feet of the liner, all of the holes in the upg~er area were within three to seven feet of the liner. Also, as previously discussed three holes extended from between 15 and 24 inches into the AVR tailings in the lower disposal area.