In the Lila Canyon area, there are primarily two coal seams located in the Blackhawk Formation: the Upper Sunnyside and the Lower Sunnyside. The two seams have merged in some places within the Lila Canyon holdings but in most areas are separate. Where separate, only one split is mineable due to the thin separation between the two splits; the separation averages 0 to 30 feet. The Upper Sunnyside seam averages 12.4 feet thick according to estimates in the Lila Canyon Mine R2P2 and in the MRP. The Lower Sunnyside seam is much thinner (0 to 5.7 feet) (BLM 2000). Therefore, the Upper Sunnyside is the seam of interest on this property. The seam is considered to be moderately gassy (i.e., methane) and is excellent quality, at 8% ash, 0.8% sulfur, and in excess of 12,000 British thermal units per pound, as-mined.

The Lila Canyon mine is located south of Horse Canyon in the Book Cliffs coalfield in Emery County. In spring of 2010, the company finished construction on 1200-foot-long rock slopes and began development work in the Sunnyside coal bed, producing 72,000 st of coal in 2010. Mine development work continued from 2011 through 2015, and total coal production averaged about 300,000 st per year in 2016, up to 1.6 million st, after the closed West Ridge mine’s refurbished longwall mining equipment was installed, and production remained at the 1.6 million st level in 2017. UtahAmerican has aggressively and successfully pursued the foreign export market and as a result increased production to 2.8 million st in 2018 and 3.7 million st in 2019, with plans to mine about 3.3 million tons in 2020. This increase was also made possible by installing a new longwall mining machine that can cut a thicker seam of coal. Coal is presently mined from federal leases where the merged upper and lower Sunnyside bed is up to 13 feet thick. Current leases at Lila Canyon will support mining for up to 10 more years, with significant reserves in adjacent unleased areas.

Existing surface-support facilities would provide the necessary infrastructure for personnel, equipment, materials and supplies, and handling and loading of coal production. These facilities are located primarily within a BLM right-of-way issued for this purpose and include structures specifically designed to minimize surface disturbances and/or to control or mitigate impacts to other non-coal resources, such as air, surface water, wildlife, and soils.

Initial mine development was completed in Lila Canyon in conjunction with prior approvals to access coal reserves and construct the Lila Canyon portals. Because of the stratigraphic location of the Upper Sunnyside coal seam where it meets the surface in Lila Canyon, the seam was accessed by 1,100-foot rock slopes. The main Lila Canyon entries are the primary “Man and Material” mine access and supply routes for the economically minable portions of the coal seam(s). The entries provide ventilation routes for all other underground workings and the principal coal haulage system (conveyer beltlines).

The modification areas are leased, continuous miners (CM) would be used to support the longwall mining methods for coal extraction. Longwall mining is used where the coal seam is reasonably continuous in order to create large enough blocks to support longwall. Continuous miners first outline a large block of coal to be mined by longwall methods.

To construct the gate-roads, the CMs cut the coal, and the coal is hauled from the face by electric shuttle cars and dumped into the feeder-breaker, which crushes large blocks and ratio-feeds the coal to the conveyor belts. Following the CM’s 10-to-20-foot cuts, roof bolters come into the area and provide roof support in a variety of ways, depending on specific conditions. Additional maintenance and support equipment and systems include personnel carriers, supply tractors and trailers, lubrication trailers, rock dust and electrical distribution systems, underground communication systems, water pumps, and mine ventilation.

The current underground mining system at Lila Canyon Mine uses a conveyor belt system to transport coal from the underground workings to the surface. The mine coal haulage system consists of several interconnected belt components (feeder breakers, take-ups, drives) to transport coal to the surface. These conveyer belts transport the coal all the way outside to a stockpile. A multi-plate reclaim tunnel is located underneath the coal stockpile for processing and loading trucks.

Two reclaim draw-down ports located at the end of the tunnel allow coal to be reclaimed from the bottom of the pile directly onto a reclaim conveyor located within the tunnel. Each reclaim port contains a pile activator, a hydraulically operated single-bladed shut-off gate, and a discharge chute leading to the reclaim conveyor. Once the coal has been loaded onto the reclaim conveyor, it is transported out from underneath the pile. The reclaim conveyor brings the coal out of the tunnel and transports it to an enclosed crushing/screening building.

From the crusher building, the crushed and screened 2-inch coal is loaded onto a covered loadout conveyor and passed to one of three product piles or transport storage pile. The coal is then transported to an automated truck loadout station. The feed conveyors (i.e., loadout conveyor and reclaim conveyor) start and stop automatically to load the individual truck trailers with a predetermined amount of coal (BLM 2000).