1996-01-23_REVISION - M1977378 (3)

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Longfellow Koehler Project Page 2 The project is located within a belt of chimney type ore deposits along the northwesterly rim of the Silverton Caldera. All volcanic rock types in this area are either from the Burns or Henson Formations. There are intrusive rocks found along the concentric and radial faults associated with the volcanic activity. The area in general is considered to be highly mineralized. The project area consists of a shaft with a small access drift and corresponding waste dump, two collapsed discharging portals with corresponding waste dumps, two mine waste dumps (estimated to contain 20,000 cubic yards)and a low pH natural pond with sediments containing metal precipitates. All water flow through or across disturbances is exposed to pyrite and other heavy metals as well as the acidic conditions of the pond. The south collapsed adit has a general Northeasterly bearing toward Carbon Lake. The headwaters of Mineral Creek are a substantial contributor of dissolved Fe,Al and Zn as defined by the 1991-1994 sampling results of Water Quality Control Division. The site features are identified on the attached drawings. Desc il2tion Pr jam; H dr Aogic Controls Infiltration Controls The upland property has not been examined by SGC to see if there are any open stopes, glory holes or other subsidence features that may be adding water to the portal flows. The following will be done to determine if infiltration controls have potential to reduce Adit flows. (1) Thorough examination of the surface looking for features which may be diverting water through mine workings. (2) Should any features be found they will be studied to see if run on run off controls are practicable. (3) SGC will implement controls such as ditching, to prevent infiltration where practicable. Site Run On Controls There exist two possible sites for run on controls at the portal area. The first source of water flows from the drainage area and pond to the North, around the Longfellow Shaft and contacts dump material before flowing into the lower pond at the portal area. The second source of flowing water needs to be evaluated but may be flowing from U.S. Basin. This stream flows next to the South (Koehler)Adit and contacts the dump material. Both sources can be best handled by simple diversion in a lined ditch to prevent any contact with contaminated water or mine waste material. The ditch water will be recombined below the site named M-2. Site Runoff ontrols