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Chapter 5 <br />Table 5-I <br />DEIS Comments and Responses <br />Commenter Comment Comment/Response <br /> <br /> federal gas lease, it is illegal to capture and use the methane. The Forest <br /> Service is working with the BLM to convey gas leases in the area to sale. <br /> Leasing the methane (gas) would allow its capture and beneficial use. <br /> BLM provided technical information (project file) on what would be needed <br /> to capture (if it were under lease) the gas and take it to a pipeline, or use it in <br /> other ways. Their findings conclude that in order to send the gas fiom the <br /> methane vent wells to a pipeline for ultimate sale, a gas treatment facility <br /> would be necessary because the gas emitted from the mine does not meet <br /> basic pipeline quality. Primarily, the level of inert constituents in the gas <br /> (COQ, N, air, others) exceeds the pipeline standard limit of 3 percent for inert <br /> constituents. Based on gas emission data from mining the B Seam at the West <br /> Elk mine, inert constituents range from 6 to 77 percent. For the purposes of <br /> this analysis, it is assumed that gas emissions from the E Seam would have a <br /> similar range of inert constituents. <br /> There would also be a need for a gas compression facility. Typically pipelines <br /> need to have gas pressures at 500 pounds per square inch (psi). In order to <br /> achieve 500 psi, the existing gas pressures would require 3 stage compression <br /> to achieve the needed level. Unlike a typical natural gas well completed in the <br /> Mesa Verde Formation in the Piceance Basin which has inherent pressures of <br /> in the 100s of psi range and do not require additional compression in early <br /> stages of operation, the MDW operate at about atmospheric pressure, or about <br /> 10 psi with an exhauster mm~ing. The MDWs would need full time wellhead <br /> or central compression to work. Although technology exists for this, there is <br /> uncertainty in how effective this technology would be given the variability of <br /> ventilation, and pressure boost needed. <br /> There are additional uncertainties regarding whether the volumes of methane <br /> being vented would warrant installation of compressors, gathering and <br /> transmission pipelines, and a gas treatment plant, since volumes vary so much <br /> with the mine operation, and are almost totally dependent upon the mine air <br /> circulation system. There are also issues related to permitting these facilities <br /> so as not to interfere with mine operations. <br /> BLM also researched using coal mine vent gas for electrical generation. There <br /> are numerous websites which show it being done, however none of them <br /> include any gas volume numbers or equipment requirement on which to base <br /> any analysis (project file). <br />Colorado Wild, et 23 Some of these alternatives are mentioned ui the DEIS summary and body as <br />al. "Alternatives Considered but Eliminated from Detailed Study". DEIS at 30- <br /> 31. The explanations for dropping all such alternatives from analysis are <br /> inadequate, and based on assertions of facts and conditions, not justified or <br /> supported with details or analysis in the DEIS. Thus there is a need to outline <br /> and review them as full EIS alternatives. <br /> RESPONSE: 40 CFR Sec. 1502.14(a) ..."for alternatives which were <br /> eliminated from detailed study, briefly discuss the reasons for their having <br /> been eliminated." References/discussions have been added to the FEIS as <br /> appropriate. <br />• <br />• <br />• <br />180 Deer Creek Ventilation Shaft and E Seam Methane Drainage Wells FEIS <br />