Laserfiche WebLink
Based on the laboratory results, the only apparent drawback to the in situ system is the potential <br />The system to be tested will consist of an in situ treatment component. The in situ test will be <br />perfotTtted by injection of nutrients and a conservative tracer (such as chloride) through a <br />monitoring well (such as BF-7) in the backfill in the Pink Gneiss Pit (Figure 1). The Pink Gneiss <br />Pi[ will be used for the pilot test because it is significantly smaller than the West Pit, and because <br />it contains similar backfill materials. In addition, the Pink Gneiss Pit is somewhat isolated from <br />the remainder of the hydrological system in the West Pit, so that the effects of the test can be <br />. sepazated from the potential effects of the proposed dewatering of the West Pit. <br />for reductive dissolution of minerals in the pit backfill material, with the possible release of <br />additional manganese, silica, and fluoride. If this occurs in the field situation, it should only be a <br />temporary phenomenon, with these components again being removed from the water by <br />precipitation ofinetal-bearing solid compounds of cazbonate and sulfide. !U,1^'~ ,~.~ ! r <br />/ ~ ,~ <br />5 ~ <br />2.0 WORK PLAN ,~^ `~ r r ~ ~~ ~ <br />r.:~ <br />2.1 Overview <br />Water quality will be monitored in the injection well and potentially in other sampling wells that <br />-~_ <br />may be installed in the Pink Gneiss Pit to measure the progress of the reactions. The decision as <br />to whether or not additional monitoring wells will be required will be based on the early results <br />from BF-7. The efficiency and progress of the reactions will be determined montlily by <br />comparing the concentrations of the tracer, the reactants, and the products. This test will begin <br />as soon as possible in the summer of 1999, and continue for up to I year. <br />The proposed work is divided into the following four tasks. <br />.~ <br />Task 1: Svstem Design and En¢ineerina: ~ ' <br />In this task both the in situ sulfate reduction system will be designed. The operational <br />parameters of the test will also be selected, including residence times, organic cazbon dosage <br />Bane Mountain Rcsoarcer Shepherd Miller, Inc <br />Ilgran/telpdrivel/003671repornldmglattachmetub.doc 5 June B, l999 <br />