2018-06-01_REVISION - C1980007 (3)

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The Grand Mesa, Uncompaghre and Gunnison National Forests (GMUG) overlie the mine. The GMUG has been negatively impacted by climate change in recent years, and therefore, GMUG management is actively practicing what the Department of Agriculture (DoA) terms, "climate smartness". This involves managing the forest's natural resources to be resilient to disturbances like wildfires, insect and disease infestations and frequent, extreme weather events. These are events that can be attributed to climate change, and reducing methane emissions supports the DoA program and USFS's efforts in practicing climate smartness. Post -mine drainage from the surface Design and installation of the GVBs used in this analysis incorporate best practices and the safety features that West Elk currently employs, including flame arresters and safety controls and monitoring, as well as all safety practices normally utilized in the oil and gas industry. It is also envisioned that all access roads and gas gathering lines will utilize existing roads and right-of-ways, not requiring any additional surface disturbance. Placement and timing of the drilling of GVBs will still be supervised by the mine and the length of time that the GVBs produce must be managed by mine personnel, as they are now, so as not to allow the gas concentration of any well to approach explosives levels. Our analysis has shown that MCC typically operates GVBs as long as mining continues on a longwall panel, but if desired, mine management could operate many of the GVBs for longer periods. With a methane mitigation system in place, this would allow for the destruction of more gas rather than eventually allowing it to escape through the ventilation system. Abatement of drained CMM from GVBs Several end -uses for the gob gas were considered in this study, but after a preliminary evaluation, flaring was determined to be the most cost-effective and economic at this time. Our conceptual design envisions that available GVB production from the new leasehold will be gathered and transported to a central location along existing roads and right-of-ways within the new leasehold boundary where an enclosed flare will be sited; no additional roads or right-of-ways will be required for gas gathering operations. Drained gas will be treated at the wellhead so that the moisture in the gas will not freeze, and then transported via 6 -inch SDR 111 plastic pipe to the flare site. The proposed flare, which will be an enclosed flare designed to destroy drained gas at 99.9 percent efficiency, would be mounted onto a concrete pad with an additional four feet of buffer, and surrounded by an enclosed fence. It will be designed to avoid over firing of the unit which could lead to air starvation and incomplete combustion. The unit is designed to shut off in cases of over firing or any type of instability in the operation. Immediately prior to shutdown, the system is equipped with a purge blower which creates a safe atmosphere within the flare, ensuring that no flames escape out the top. The system is also equipped with a UV scanner; if the pilot flame is lost, the main flame automatically shuts down. During all shutdown cases, the system immediately goes into safe mode, whereas gas is prohibited from contact with the flare unit. Also, the flare chamber is internally lined with refractory material, minimizing the impact of the flare on the outside shell temperature which further reduces any 1 SDR 11 means that the outside diameter of the pipe is eleven times the thickness of the pipe wall. 11