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The Leadville Mill animal - friendly wire fence (Appendix 7 -9, Colorado Division of Wildlife Consultation). The perimeter fence modifications were completed in 2012. 3.7 WATER RESOURCES & HYDROLOGY (SEC 6.3.2(C)) M 1990 -057 EXHIBIT B —SITE DESCRIPTION Page 3 -5 Communication with the Colorado State Engineers, Ground Water Section, in 1990, indicates the shallowest known aquifer in this area to be 80ft to 100ft below surface. These data are based on well logs of the nearest water wells to the mill site. Groundwater including stormwater management during operation is discussed in Section 14, Exhibit U. The Mill is located in the Arkansas River Basin flowing south - southeast before it turns east near Pueblo, Colorado. The Arkansas River Basin defines the Colorado Division of Water Resources Management Division 2 with its division office located in Pueblo. A thin veneer of soil with moderate to high permeability generally less than 5ft thick overlies the bedrock. The surficial materials are generally not extensive enough to yield suitable quantities of water but are an important unit for recharge and shallow, seasonal groundwater. Recent studies suggest approximately 84% of the available precipitation is evaporated and only a fraction of the remaining 16% recharges the aquifer systems. The porosity of the Precambrian crystalline rocks is very low ( <1 %). Transmissivities are Tess than 10gaI /day -ft (Apodaca and others, 1996). Groundwater discharge and storage in crystalline rocks occurs in fractures. Predominant recharge is from snowmelt between the middle of May and the first part of July. Water levels can vary as much as 10ft depending on the season and amount of precipitation. Depths to water in crystalline rocks generally are less than 150ft deep and depend on the topography and the fracture system. Water well yields from the majority of domestic wells are generally less than 5gpm. The alluvium and alluvial terrace deposits are the primary groundwater sources for domestic uses with well yields ranging from a few gallons a minute to over 50gpm with a mean production rate of 25gpm. Alluvial well depths range from less than 10ft to over 100ft with the mean depth of 53ft. Many of the upper basin wells record strong seasonal fluctuations with the highest water levels correlating to snow melt and spring runoff events. Version 1.0 April 2013