Laserfiche WebLink
~~ HOM'AIGE <br />ALAN D. COX <br />CORPORATE MANAGER, ENVIRONMENTAL AFFAIRS <br />R~CE11; ~D <br />December 2, 1997 <br />State of Colorado <br />Department of Natural Resources <br />j 0: Division of Minerals and Geology <br />1313 Sherman St., Room 215 <br />Denver, CO 80203 <br />Attn: Mr. Allen Sorensen ,Reclamation Specialist <br />nFC o g 1997 r~ <br />PlNisipn of I,n~nuralS x F,~aiapy <br />Voc • ~v c, w~-r r. <br />RE: Bulldog Mine Reclamation -Monthly Report -Infiltration Trench Monitoring <br />Dear Mr. Sorensen: <br />Pursuant to our most recent Technical Revision to the Reclamation Permit for the <br />Bulldog reclamation project, attached is a copy of the monitoring data and <br />associated water quality analyses for the 9360 adit water seepage which is <br />currently being managed via trench infiltration. <br />Pursuant to our recent meeting discussions, we will be forwarding a proposal for <br />installation of two 121 vadose zone shallow monitoring wells (+/- 20 ft.) <br />downgradient of the infiltration trench. Upon your review and concurrence with the <br />proposal we will seek a drilling contractor to complete the well installations. <br />As you are aware, we have been managing the seepage from the 9360 adit since <br />last Spring as part of our program to develop a permanent remedial solution for <br />what has been, prior to this year, a seasonal seepage issue. Approximately 8 <br />weeks ago, a decision was made to re-enter the 9360 adit to determine the <br />source(s) of the continued seepage this year and to collect additional data <br />necessary to design a remedy. These efforts were complicated after encountering <br />a caved in section in the adit approximately 300 feet in from the portal. Work <br />continues with a focus on continuing to control and manage seepage water coming <br />from the adit. In mid-November, cold weather conditions precluded continued use <br />of the spray system for managing water; since that time flows have been into the <br />infiltration trench and have remained below a 30 gpm threshold. Trench infiltration <br />performance has considerably exceeded expectations and continues to be effective <br />in managing seepage. <br />Two samples of the adit seepage water were taken on November 5 at the caved <br />section face and at the entrance of water into the infiltration trench; analysis data <br />HOMESTAKE MINING COMPANY <br />650 CALIFORNIA STREET • SAN FRANCISCO • CA 9<109~2]69 (4~5196t-6150 <br />