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the waste stream is water carried, there is very limited noise pollution as heavy equipment is only needed <br />,s during maintenance procedures and for placement of cover materials and re-vegetation. <br />J. The waste product is entirely non-flammable, therefore fire mitigation will not be necessary. <br />K. During operations the potential for windblown debris is confined to the exposed face of the impoundment. <br />Temporary cover consisting of geotextiles will be used to control windblown debris from this area. The <br />area behind the dam is inundated with water during normal operations. During periods of in-activity, the <br />potential exists for windblown debris from this portion of a cell. In the event of this situation, water will be <br />applied with sprinklers and/or the area will be covered with geotextile fabric. <br />L. A catchment and settling basin will be constructed down gradient of the disposal cell to intercept and settle <br />sediment from surface water run-off in the event of such an occurrence. Leachate shall be collected and <br />returned by pumping to the impoundment and/or water storage tanks above the mill. Impacts to surface <br />water will be controlled as per the stormwater management plan (Appendix D) and design details found in <br />the Tailings Impoundment Design Drawings (Appendix Q. <br />Impacts to groundwater will be controlled by the recycling of leachate to the process stream, the sealing of <br />joints and fractures in bedrock by the clay content of the hydraulically classified waste stream, and the <br />chemical control of the process water quality as enumerated in 3.3.2.C. <br />M. Water for the operations is obtained from the municipal water supply of the City of Idaho Springs. It is <br />delivered to the site by a 2" line by pumping and stored in a 50,000 gallon tank and/or open reservoir for <br />use in operations. Additionally, all process water is reclaimed by the means of a pontoon mounted pump or <br />sump pump from the impoundment. Water consumed by the operation consists of losses due to <br />evaporation and interstitial water in the porous spaces between the grains of waste (which is impossible to <br />remove due to capillary pressure). Water consumption is estimated at a maximum of 6,700 gallons per day <br />by evaporation and capillary losses. Additional water of 100-200 gallons per day may be used for dust <br />control on company owned roads. The tap from Idaho Springs is capable of producing approximately <br />57,600 gallons per day and is adequate for all anticipated needs. <br />2.1.2 Hazardous waste exclusion plan <br />There is no potential for any other waste, hazardous or otherwise, to enter into this waste stream. Only material <br />from Company owned properties will be disposed, which is entirely composed of existing mine waste rock <br />dumps. A pH monitor and data recorder will be installed at the tailings pump location within the mill. Should <br />the pH reach a state outside of the 7.5-9 range that is necessary to precipitate the heavy metals, alarm <br />notification will be activated for the operations personnel. The submittal notes on this Serfilco Model 432 <br />monitor/recorder can be found in Appendix N. <br />If the pH falls outside of the 7.5-9 range, the operators are instructed to shut down the tailings pump that <br />delivers waste to the impoundment. Once the source of the problem is corrected upstream in the process, waste <br />can then be discharged to the impoundment. <br />Refer to Appendix E (A Water Handbook for Metal Mining Operations, by Thomas R. Wildeman) for a detailed <br />explanation of the chemistry associated with precipitation of heavy metals in an alkaline water environment. It <br />should be noted this report was prepared under a grant from the US Department of the Interior. <br />2.1.6 Surface water control systems <br />A stormwater management plan is created as follows for the construction and operations of the disposal site: <br />1. Construct sedimentation basin. <br />2. Construct earthen lined diversion ditches and connect natural diversion channels to sedimentation <br />basin. <br />3. Construct leachate collection barrier. <br />4. Rip-rap and/or vegetate tailings dam face using appropriate controls, i.e. jute netting and/or hydro- <br />mulch using high-altitude roadside seed mix. <br />4