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runoff as well as runoff from reclaimed waste rock facilities B and C and the East Pit and <br />West Pit areas. This stormwater collection, diversion, and conveyance system has been <br />designed to collect, convey, and store a 10-year, 24-hour storm event from the <br />aforementioned facilities and the upgradient stormwater diversions. Two retention ponds <br />have been installed in the area of Waste Rock Facility A to contain this storm event. In <br />the event of a storm event in excess of the design event, the additional stormwater would <br />overflow through an armored spillway and apron located on the lower pond (Figure 1). <br />Risk Assessment <br />As previously discussed, geochemical testing was performed to determine the potential <br />for surface water runoff from the waste rock facilities to contain pollutants other than <br />sediment. These tests indicated that waste rock materials do not leach constituents in <br />quantities that would affect the surface water quality. The risk of sediment transfer was <br />greatly reduced by the concurrent reclamation of the facilities that contribute drainage to <br />the system. Additionally, the design to retain the 10-year, 24-hour storm event in the two <br />retention ponds located at the foot of the system will minimize the risk for transfer of <br />sediment pollutant to surface water. Any exposed construction materials within the <br />diversion, collection, and storage system were characterized using standard geochemical <br />testing procedures upon completion of construction. <br />Applicable BMPs and Good Housekeeper Practices <br />When the Project was designed and constmcted, BMRI employed stormwater best <br />management practices in the development of the waste rock facilities and pit backfills as <br />discussed in the approved DMG permit and technical revisions. The primary BMP for <br />minimizing sediment generation and stormwater exposure to waste rock materials was <br />the concurrent reclamation practiced at the site. Vegetative establishment reduces <br />sediment generation and the potential for exposure of waste rock materials. With <br />concurrent reclamation, early vegetation of the lower benches or lifts provided filtration <br />for sediments present in runoff from unreclaimed or upper lift areas that were reclaimed <br />at a later date. Small catch benches were left in place as each subsequent lift was graded. <br />This catch bench provides a mechanism for slowing runoff from the slopes and allowing <br />collection of sediment. <br />Battle Mountain Resources, Inc. Telesto Solutions, Inc. <br />,a~ m~,~o,m~,~~e. ma~~aeme~wm~.da 17 May 3, 1002 <br />