2008-06-09_REVISION - C1980007 (3)

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• • Water MCC maintains monitoring stations and regularly monitors flows and water quality on Minnesota Creek, Deep Creek, Dry Fork, and the North Fork of the Gunnison River. Flow measurements and field parameters are typically collected three times per year and water quality sampling occurs amlually. Commitments for future monitoring are tied to initiation of active mining within a watershed area, with initial monitoring at least one year in advance of mining disturbance. In compliance with the terms of their approved DRMS mining permit, MCC will continue to monitor surface water flows and quality for all potentially affected surface drainages that overlie active mining areas. The Project File contains surface water quality data collected by MCC and others in the greater mine area from various tributaries of the North Fork. Water quality from the tributaries is generally consistent with North Fork water quality. Total dissolved solids, total settleable solids, and iron concentrations can increase dramatically during spring runoff and intense storm events, particularly in the smaller drainages. Water quality of streams can vary dramatically depending on time of year, volume of surface flows, and location. After the late spring/early summer snow melt runoff, all surface water in the project area originates from springs and seeps. The exception to this is the aforementioned contribution by Deep Creek Ditch and any significant summer precipitation events. Seeps and springs originate from either shallow perched water tables or from bedrock outcrops. Based on a map of surveyed springs and stock ponds provided in the Annual Hydrology Report (Exhibit 71, Map No. 1 and Exhibit 19c,), there are approximately 6 perennial, one decreed, and 53 intermittent or historical springs in the project area (MCC 2007b). Bedrock springs in the project area originate in the Barren Member of the Mesa Verde Formation (USDA FS 2002a). Approximately 2/3 of the surveyed springs originate as bedrock springs based on their position relative to the bottom of the ephemeral and intermittent stream drainages. These springs exhibit seasonal fluctuation in flow, though not as pronounced as the shallow ground water springs. Water from bedrock springs is generally more saline than the surface water and shallow water table springs in the area. Some of the springs and seeps in the project area have been captured by shallow seep basins and stock-water ponds developed to support livestock and wildlife. Based on review of the springs and seep survey map, there are 36 stock ponds in the study area. Ground Water MCC maintains a network of 28 ground water monitoring wells throughout the West Elk Mine permit and lease areas. A portion of this network covers the project area (Figure 6). The following monitoring wells have been affected by long wall mining subsidence resulting in collapsed well casing and are no longer available to the monitoring network (SO W- 1, SOM -45-H1, SOM 2H, SOM -16H, and 96- 27-1). In 2005, four old wells (23H-1, 23H-2, 23H-3, and 23H-4) were reinitiated into the well network. Monitoring wells in the project area provide important background information on water quality and a database from which to judge direct and indirect effects of mining activities on ground water resources. Shallow ground water in the project area is limited due to geomorphologic controls from the relatively steep gradients and stream profiles of drainages, resulting in thin alluvial/colluvial deposits confined to the drainage bottoms. Ground water that surfaces as springs and seeps in drainage bottoms is associated with these shallow alluvial/colluvial deposits and does not appear to be hydrologi- cally connected with deeper bedrock aquifers. There two shallow alluvial monitoring wells in the project area that are monitored as part of the West Elk hydrologic program, the Upper Dry Deer Creek Ventilation Shaft and E Seain Methane Drainage Wells FEIS 63