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• small amounts of water as the adjacent tailings consolidate. As stated in BMRI's November 30, 1993 letter to the Division, BMRI does not believe that the in-tailings piezometers will provide meaningful data for the construction of the second raise. The piezometers will not determine the location or thickness of a potentially water bearing zone. The piezometers will provide no data on the density, undrained shear strength or steady-state strength of the water bearing layers which can be incorporated into a stability analysis of the second raise. Stipulation No. 2 stated: "The operator will install markers to delineate the set-back required between the tailings embankment and the free water pond. The markers must be clearly visible and adequate to allow straight forward verification in the field that the required set-back is maintained." BMRI's letter dated November 30, 1993 to the Division addressed the issue of establishing a setback for the water edge of the lower pond from the main embankment such that the run-off from the 100-year, 24-hour storm event would be held within the tailings facility but not in direct contact with the upstream face of the main embankment. Based on the surveyed average beach slope and the total inflow to the area from the storm event as estimated through standard Soil Conservation Service methods, a conservative water pool setback from the main embankment of 250 feet will more than hold the event and the associated run-off. In early February, setback markers were surveyed to location and staked at 250 feet upstream of the main embankment. The terms and conditions of the TR-16 approval have been fully completed. If you have any questions, please call. Sincerely, Alana L. Scott Technical Superintendent cc: Anne Baldrige Dan Robertson Sally Hayes