Cheatham County Generation Site EIS Scoping Report
3.2.2 Water Requirements Some on-site water treatment would be required to support the facility’s need for demineralized water. The CT plants would require potable water, which would be obtained from the existing public supply. CHG would not require any uptake water from Sycamore Creek or discharge into Sycamore Creek. Up to about 100 gallons per minute (gpm) of potable water as provided by the local water utility would be used for inlet air evaporative cooling in summer ambient temperatures. CT compressor washing and turbine power augmentation requires demineralized water. Wash effluent would be collected in tanks and, after analysis, disposed of at an approved wastewater treatment facility off-site. 3.2.3 Emission Monitoring and Controls Operating the aeroderivative CTs would require emission monitoring and controls. Reduction of emissions of oxides of nitrogen (NOx) from CTs would be achieved through dry low-NOx (DLN) and dry- low emissions (DLE) combustion systems and Selective Catalytic Reduction (SCR). The SCR system would use 19.5 percent aqueous ammonia that would require an independent storage/receiving system to be installed. Reduction of carbon monoxide (CO) would be achieved using a separate catalyst layer, specifically for that pollutant. The new exhaust stacks would be equipped with continuous emissions monitoring systems for CO, NOx, and oxygen. 3.2.4 Natural Gas Pipeline The operation of the proposed CT plant will require construction of a new approximately 8-mile natural gas pipeline lateral and gas system infrastructure to connect the plant to the new gas pipeline. The pipeline construction and operation would be undertaken by a pipeline company and will be treated as a related action in this EIS. The proposed gas pipeline system overview map is shown in Figure 1 and identifies the preliminary route of a new natural gas pipeline that would be up to 30 inches in diameter. A portion of the proposed new pipeline would be partially co-located within an existing electric transmission right of way (ROW). The CT plant would be fueled by a reliable supply of natural gas. Preliminary estimates indicate that approximately 221,000,000 standard cubic feet per day (SCFD) of natural gas would be required for the CT plant. Natural gas will be delivered to the site at a minimum pressure of 610 pounds per square inch (lb/in 2 ). On-site gas compression will be required with compression requirements determined by the technical requirements of the frame and aero CTs brands and models chosen. Gas compressors with electric motors will be incorporated during the design phase. 3.2.5 Fuel Oil The design of the Action Alternative will include utilization of ultra-low-sulfur diesel (ULSD), a petroleum fuel, as an emergency backup fuel for the aero CTs. This ULSD fuel-oil would be permitted to be used as emergency back-up fuel only. Consideration of ‘dual fuel’ at CHG relates directly to issues of fuel security and resiliency. Resiliency, as applied to the power system when faced with a trigger event (e.g., natural, intentional, physical, or digital/cyberterrorism events), includes two concepts: • Response: Flexibility of a system to respond quickly to a trigger event; and
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