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Gold Prince Mill Tailings and Waste Dump <br /> Page 2 <br /> Site Loading Estimate <br /> Based on limited information the site loading estimate for this project site is based on: <br /> Adits- <br /> Using available data, zinc loading was calculated based on the average flow and average zinc <br /> values. <br /> Mine Waste Dumps and Tailings Piles- <br /> Site composite soil samples were tested using a water bath extraction. This test consists of <br /> exposing a 1:1 ratio by weight of material to deionized water. The mixture is briefly mixed then <br /> allowed to set for 30 minutes. The sample was then filtered ( 0.45 micron) and analyzed for metals. <br /> Annualized loading was calculated using rainfall data (proportionally adjusted for site <br /> elevation between the Silverton and Red Mountain weather stations), exposed area of waste dump <br /> or tailings site and loading based on 1:1 water bath test results. For comparison to adit flow loadings <br /> projects, the annualized loading was converted to an average daily loading. <br /> Based on these assumptions and procedures, SGC estimates that the average daily loading for <br /> this site may be as much as 0.4 pounds of dissolved zinc per day. SGC is under no obligation to <br /> defend these estimates and they should only be used as an estimate. SGC does not represent that its <br /> mitigation project at this site will remove any specific percentage of metals loading from this site: the <br /> loading estimate contained herein does not form the basis of an enforceable permit obligation. <br /> Description of Project <br /> The surface tailings and waste rock will be removed and consolidated and the pH adjusted to <br /> near neutral by addition of lime or limestone. A suitable relocation area for tailings and waste rock <br /> will be built onsite. The onsite relocation area will have a diversion trench established around it to <br /> isolate the material. All surface soils will be salvaged and used for final capping. Final cap thickness <br /> will depend on the amount of soil available for salvage, 14-16" minimum is preferable. Construction <br /> of the relocation site will conform as near as possible to the site topography with maximum slope <br /> ratios of 2:1. The relocation area will be located as far away from streams as practical. Once all <br /> material is consolidated,the area will be capped with the salvaged soils, amendments added, seeded <br /> and mulched. All surface disturbances will be reseeded. It is possible that a 404 permit from the <br /> Army Corps of Engineers may need to be obtained before performing this work. This plan is also <br /> subject to notification requirements, for disturbance of Historical Mining Sites, to the board of the <br /> San Juan County Commissioners. <br /> At the portal, the closure bulkhead will be reinforced with concrete and grouted to prevent <br /> water from flowing out the portal. The tunnel would then no longer be a drain for the near surface <br /> fractures in the area. Surface disturbances will be treated with soil amendments and reseeded. <br /> The property has some building foundations on it and may be deemed as historic. SGC will <br /> preserve these structures provided that the mine waste can be economically removed without major <br /> damage or demolition of structures. <br />