2000-08-25_REVISION - M1977378 ‎(2)‎

• Permit No: M1977378
• IBM Index Class Name: REVISION
• Doc Date: 8/25/2000
• Doc Name: Submittal
• From: Sunnyside Gold Corp
• To: DMG
• Type & Sequence: TR22
• Media Type: D
• Archive: No

Dear Mr. Erickson:
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StINNYSIDE GOLD CORPORATION f Min erals Oryioe
AN ECIIO DAY COMPANY `� Ge p/ogy
P.O. Box 177 • Silverton, CO 81433 b`rv�
Phone [phone] • Fax [phone] U BL /
August 23, 2000 t / f �. _' 2> 3 o �Y
Mr. Wally Erickson, Reclamation Specialist
Division of Minerals and Geology
Department of Natural Resources
484 Turner Drive, Bldg. F, Suite 101
Durango, CO 81301
RE: File No. M47 -378, San Juan County
Terry Tunnel Near Surface Tunnel Bulkhead
/R -22 Submittal
Sunnyside Gold Corporation (SGC) installed a bulkhead in the Terry Tunnel to eliminate
drainage through the tunnel to surface from the Sunnyside Mine (TR -14). This bulkhead
is located 3800' from the portal and has been in service since 1996. Since valve closure
in 1996, there has been a seasonal drainage from the Terry Tunnel. Initially, this flow was
small enough that infiltration and evaporation exceeded the flow and no discharge
occurred from the Terry Tunnel settling ponds, the site CDPS permit does not anticipate a
discharge after December 31, 1996. In 1999, the recharged groundwater system (from
removing the drain created by the Sunnyside Mine) started draining to the near surface
fracture system which is intersected by the Terry Tunnel. The water is not from the mine
pool and would meet the existing permit numerical limits except for pH which has been
approximately 6.4 while the permit requires 7.0. This increased flow started exceeding
the infiltration and evaporation rate and SGC, in order to maintain the no discharge status
anticipated in the site CDPS permit, began pumping the captured flow into the Sunnyside
Mine pool through the bulkhead valve. This is an expensive and time consuming process
and cannot be carried out through the winter months because the site is not accessible in
the winter. Since it has been established that the rise of the mine pool leveled off in
November 1999, SGC proposes to reclaim this site to progress towards final reclamation
and minimize future expenditures. Therefore, SGC proposes to install an additional near
surface bulkhead to; impound as much of the flow as the design process will allow;
recharge water back into the water producing fractures intersecting the tunnel; and reduce
the oxidation rate in the fracture system and tunnel by re- establishing an approximation
of the pre - mining hydrology.
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