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The alluvial ground water recharges the rock strata in the area. The spoils in the southwest section of the mine support continuously flowing ground water seeps. These areas of the mine are below the level of Stollsteimer Creek and the water table of the Stollsteimer Creek alluvium. Piteau and Associates, using pumping test values for the affected stratum and coals, calculated a theoretical inflow of 10 gpm for the same pit. The permittee did not mine through this alluvial aquifer, although some surface facilities were located on the alluvium. 2. Surface Water Monitoring Information pertaining to the surface water quality and quantity can be found in Sections 2.04 and 2.05 of the permit. Additional surface water hydrology information is provided in the application by Exhibit 7 and Maps 4 and 8. Information pertaining to sediment control structures can be found in Exhibit 7 of the permit revision application. The approved permit area is drained by one perennial drainage, Stollsteimer Creek. Flows in Stollsteimer Creek vary seasonally; highest flows occur during periods of snowmelt and intense thunderstorms. Stollsteimer Creek receives flow from numerous ephemeral drainages. This creek is dammed in numerous locations above the permit area, the closest dam being located at Capote Lake, approximately five miles upstream. The landowner has constructed an irrigation ditch which runs adjacent to the creek. This ditch is periodically dammed to flood irrigate the pasture located between the East Pit and the Barren Ridge permit area. Mining operations did not preclude the use of this irrigation ditch. All runoffs from disturbed areas are currently routed through four sediment control ponds. Sediment pond 002 is located on the western edge of the East Pit Area. Sediment pond 003 is located on the northeastern edge of the permit boundary. Two sediment ponds, 004 and 005, serve as sediment control structures in the Barren Ridge and Federal Lease Areas. The sediment trap is located below pond 2. All of the above-mentioned sediment structures were designed and constructed under the supervision of a registered professional engineer. The ponds will contain the runoff from a 10-year 24-hour precipitation event without discharging. The emergency spillways will pass a 25-year 24-hour event and still maintain the required freeboard. Maintenance of the ponds includes periodic inspections to ensure the integrity of the structure. Sediment volumes are checked monthly and cleaned when 60 percent of the design sediment storage volume is attained. _12_