The Tennessee Valley Authority issued a final environmental assessment (EA), a finding of no significant impact (FONSI), and a decision memorandum on its proposal to construct and operate air pollution control equipment and associated facilities at its coal-fired Gallatin Fossil Plant.
In order to meet the new Mercury and Air Toxics Standards, and to comply with air agreements with regulators and environmental groups, TVA proposes to construct and operate dry flue gas desulfurization, selective catalytic reduction, pulse jet fabric filter, and activated carbon injection systems.
TVA also proposes to construct and operate a landfill on the Gallatin site for the dry storage of the coal combustion residues. TVA has been converting its wet ash impoundments to dry since a catastrophic failure a few years ago of an impoundment dam at its Kingston coal plant.
The proposed action at Gallatin, with a total pricetag of about $1.1bn, will result in substantial reductions in emissions of SO2, NOx, mercury, and acid gases. As required by the National Environmental Policy Act, TVA developed an EA for this action. Based on the evaluations in the final EA, issued on Mrch 12m TVA said it determined that the proposed action would not result in significant impacts on the environment and therefore issued the FONSI.
TVA began construction of Gallatin (GAF) in 1953, and began operating Unit 1 in 1956 All units were operating by 1959. GAF’s powerhouse, coal yard, coal waste surface impoundments, and additional facilities are located along the north bank of the Cumberland River.
GAF operates four coal-fired, steam-generating units and combusts an average of 12,350 tons of coal per day. Units 1 and 2 each have generator nameplate ratings of 300 MW, and Units 3 and 4 each have generator nameplate ratings of 327.6 MW. Four combustion-turbine (CT) units were added to GAF in the early 1970s, and another four were added in 2000. They are primarily fueled with natural gas but have the capability to use fuel oil. The CT units support the TVA system’s peak energy demand.
TVA has installed electrostatic precipitators (ESPs) at GAF to reduce particulate matter (PM) emissions and low-NOX burners to reduce NOX emissions. TVA also burns low-sulfur blend coal, primarily coal from the Powder River Basin, at Gallatin to reduce emissions of SO2. Currently, approximately 185,000 dry tons of fly ash and approximately 46,500 dry tons of bottom ash are wet-sluiced to GAF’s surface impoundments each year.
Environmental groups have been opposing the projects, saying that Gallatin should be shut instead. TVA already plans to shut other coal-fired units for the same reasons it now wants to retrofit Gallatin.