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Addition of Electric Generation Peaking Capacity at Greenfield Sites, Mississippi

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Tennessee Valley Authority.


Issuance of Record of Decision.


This notice is provided in accordance with the Council on Environmental Quality's regulations (40 CFR parts 1500 to 1508) and TVA's procedures implementing the National Environmental Policy Act. TVA has decided to adopt the preferred alternative identified in its Final Environmental Impact Statement for the Addition of Electric Generation Peaking Capacity at Greenfield Sites, Mississippi.

The Final Environmental Impact Statement (FEIS) was made available to the public in March 2001. A Notice of Availability (NOA) of the Final EIS was published by the Environmental Protection Agency in the Federal Register on March 16, 2001. Under the preferred alternative, TVA has decided to construct a natural gas-fired simple cycle combustion turbine (CT) plant with up to 340 Megawatts (MW) of new peaking capacity at a site in Kemper County Mississippi as early as May 2002.

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Bruce L. Yeager, Senior Specialist, National Environmental Policy Act, Environmental Policy and Planning, Tennessee Valley Authority, 400 West Summit Hill Drive, mail stop WT 8C, Knoxville, Tennessee 37902-1499; telephone (865) 632-8051 or e-mail

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In December 1995, TVA completed and published Energy Vision 2020—Integrated Resource Plan/ Programmatic Environmental Impact Statement. Energy Vision 2020 projected demands for electricity in the TVA power service area through 2020 and evaluated and recommended ways of meeting the projected increases. Energy Vision 2020 evaluated an array of power supply technologies, both supply-side and demand-side. A portfolio of options drawn from several effective strategies was chosen as TVA's preferred alternative. In this preferred alternative, three supply-side options were selected to meet peak capacity needs:

  • Addition of CTs to TVA's generation system,
  • Purchase of market peaking capacity, and
  • Call alternatives on peaking capacity.

The short-term action plan of Energy Vision 2020 identified a need for 3,000 MWs of baseload and peaking additions through the year 2002. Since Energy Vision 2020 was completed in 1995, TVA has continued to evaluate and select the best resource alternatives based on the latest proposals and TVA's forecast of power needs. TVA's projections show expected peak demands growing at 2.4% from 2000 to 2005 and beyond. The net capacity Start Printed Page 21190resources needed to meet the growth in demand increases 2,000 MWs by 2002, and 3,400 by year 2004. The addition of the combustion turbines proposed in this EIS is needed by TVA to meet the peaking capacity requirements from both a reliability and cost standpoint.

Tiering from the Energy Vision 2020 EIS, this FEIS for Addition of Electric Generation Peaking Capacity at Greenfield Sites, Mississippi, presents a site-specific analysis of the impacts expected to result from the addition of new CTs to TVA's power system for meeting electricity needs during periods of high demand (peaking). In addition to peaking capacity requirements on the TVA system as a whole, increased demands on the TVA transmission system are creating a need for new transmission lines and/or other transmission system upgrades in the western end of the TVA system. Installation of the necessary new generating capacity in an area most beneficial to the transmission system would enable TVA to delay some transmission system improvements, thereby reducing costs and avoiding environmental impacts.


On page 3 of the Executive Summary for the FEIS, under the heading “No Action Alternative,” reference is made to “anticipated demands by May 2001.” This should read, “anticipated demands by May 2002.”

Table 4-1 of the FEIS erroneously states the diameter of stack number 4 to be 435 meters. It should read 4.5 meters.

Alternatives Considered

The No Action alternative would result in TVA not constructing a combustion turbine generating plant at either of the alternative sites in Kemper County, Mississippi. Under this alternative, TVA could still add additional turbine units at its Lagoon Creek Combustion Turbine Plant (in addition to the units under construction) to build out that facility in accordance with its completed NEPA review and construction air permit. This approach, however, would not achieve the needed transmission system benefits offered by the Kemper County sites. TVA also could either undertake no new activities to meet anticipated demands by May 2002 for peaking power, or could rely exclusively on options from the Energy Vision 2020 portfolio that do not involve construction and operation of new TVA fossil capacity. However, there is an unacceptable risk that relying on those approaches alone would not allow TVA to meet future customer demands for low-cost, reliable power.

Feasible action alternatives for meeting the stated purpose and need include the entire portfolio of actions recommended in Energy Vision 2020. These actions include various supply-side actions, customer service alternatives, and environmental control alternatives. TVA is currently using all of these Energy Vision 2020 recommended options, and managing their use in a way which provides optimum flexibility at the lowest cost. However TVA's generation (or avoidance of demand) is not sufficient to meet future peaking demands. The only action alternatives considered reasonable for detailed assessment in this EIS were the proposed construction and operation of combustion turbines at one of two sites in Kemper County, Mississippi.

An extensive screening was performed of possible site, plant, power line, pipeline, and other project alternatives, using a number of technical, economic, and environmental criteria. The candidate sites were selected based primarily upon the following criteria: power transmission (system support, connection cost, and system losses); natural gas supply (pipeline availability, capacity and delivered fuel cost), air quality impacts (likelihood of the area being able to incorporate additional emissions); and water supply (surface or groundwater availability). At the conclusion of this effort, two alternatives sites were selected for detailed evaluation in the EIS. The EIS assessed the impacts of one plant configuration. Both sites are situated north of Highway 16 between DeKalb and Scooba near the Tennessee Gas Company natural gas pipeline.

Potential routes for a new 161-kV transmission line from the DeKalb Substation to the sites, a water supply pipeline, backup power, and a natural gas pipeline for connecting with the Tennessee Gas pipeline (needed for the Hamilton Branch Site) were evaluated for potential impacts. In addition, one 28.3-mile section of the existing 161-kV transmission line from the DeKalb Substation to the Philadelphia Substation and one 44.4-mile section of the existing 161-kV transmission line from DeKalb Substation to the Weyerhaeuser Substation would require uprating to carry the increased load. Infrastructure requirements for the site alternatives are very similar, except that the Hamilton Branch Site would require a short natural gas pipeline segment to connect with the Tennessee Gas pipeline.


TVA has decided to implement the preferred alternative which is to construct a natural gas-fired simple cycle combustion turbine plant with up to 340 Megawatts (MW) of new capacity at the Sucarnoochee Creek site in Kemper County, Mississippi. TVA will also build the associated transmission lines connecting to the TVA power distribution system, a power line for the facility construction and emergency power source, a connection to the Town of Dekalb water supply, a natural gas connection to the on-site Tennessee Gas Company supply line, and upgrade existing transmission lines from the Philadelphia substation to the Dekalb substation and from the Dekalb substation to the Weyerhaeuser substation to accommodate the increased loads.

Environmentally Preferred Alternative

As discussed below under Environmental Consequences and Commitments, the environmentally preferred and TVA's preferred alternative is to construct and operate a combustion turbine electric generating plant at the Sucarnoochee Creek Site in Kemper County, Mississippi.

Environmental Consequences and Commitments

No significant adverse environmental impacts were identified in the FEIS. As a simple-cycle combustion turbine, there are minimal water supply requirements and minimal wastewater discharges. For both the Sucarnoochee Creek and Hamilton Branch sites no wetlands would be impacted by site development, because all wetlands are outside the plant construction zone footprint. However, the ancillary transmission, water supply and gas pipeline corridors could affect up to 2.35 acres of wetlands for the Sucarnoochee Creek site and up to 7.27 acres of wetlands for the Hamilton Branch site.

Except for five environmental criteria, the impacts of constructing and operating the proposed 340 MW peaking plant and its associated structures (e.g., transmission lines and pipelines) would be indistinguishable at the two alternative sites. The Hamilton Branch site has no historical properties present; slightly lower potential impacts on the nearest noise receptors; and no acres of prime farmland that would be permanently removed from production (as compared to 35 acres for the Sucarnoochee Creek site). There are two historic properties at the Sucarnoochee site (impacts to these sites would be Start Printed Page 21191avoided or mitigated as described below). The Hamilton Branch site could result in construction of substantial portions of the project within the 100-year floodplain, whereas, at the Sucarnoochee Creek site, no construction would take place within the 100- or 500-year floodplain. Because the Sucarnoochee Creek site can be developed without construction within the 100-year floodplain, it is clearly the preferred site from a floodplains/flood risk standpoint. Additionally, the Sucarnoochee Creek site affects about half as many currently forested acres as the Hamilton Branch site (65 acres) does. In the final analysis, these differences marginally support the Sucarnoochee Creek site as being the environmentally preferred alternative.

Best Management Practices (BMPs) will be used to reduce erosion and runoff during construction, including site activities, construction of construction/emergency power line connections, natural gas pipeline connections, and water supply pipelines. These standard construction and best management practices (BMPs), including such measures as using temporary berms, strawbales or silt fences and reseeding and revegetating areas of soil disturbance, would be followed in project construction and operation to avoid or minimize potential environmental impacts to surface waters, aquatic ecology, terrestrial ecology, threatened or endangered species, land use/soils, floodplains, and transportation.

Planned mitigation measures are assumed to be implemented as part of the actions proposed and provide the basis for the identification of environmental impacts. In other words, these additional measures are integrated into the action and will be conducted as part of the project. These measures are generally of two types:

  • Components incorporated during project design and construction that would be part of operational activities of the plant, and
  • Programs and environmental controls initiated to meet regulatory standards.

In addition to BMPs discussed above, these measures which will be implemented, are identified under the following specific resource headings.

Air Resources

  • Open construction areas and unpaved roads will be sprinkled with water to reduce fugitive dust emissions.
  • When firing with natural gas, the plant will use best available control technology such as dry low NOX burners (DLN) to control NOX emissions. When firing with oil, water injection will be used as a NOX control measure.
  • The plant will use best available control technology to minimize releases of other criteria air pollutants.
  • When firing with oil, low sulfur fuel oil will be used.

Surface Water Resources

  • Retention pond(s) will be used to manage/release site runoff.
  • Construction of retention/settling pond(s) will be completed as early in the construction phase as feasibly possible.
  • Oil/water separator(s) will be used to collect oil from oil using/storage areas.
  • Areas disturbed by the initial phases of construction, such as equipment laydown areas and construction temporary parking, will be revegetated before beginning the second phase of construction, if applicable.

Groundwater Resources.

  • If neighboring wells are adversely affected by aquifer drawdowns, TVA will modify the well to lower the pump intake, install a new well or provide a connection to public water supplies, if available.

Floodplains and Flood Risk

  • If a site with a floodplain is selected, all flood damageable facilities and equipment will be elevated above or floodproofed to the 100-year flood elevation to ensure compliance with EO 11988.
  • Transmission line right of ways will be revegetated to reduce erosion.

Aquatic Ecology

  • Monitoring of aquatic life impacts will be conducted during periods of wet stream blasting.


  • Existing roads, right or ways, and higher elevations, will be used when feasible, for movement of construction vehicles along proposed linear feature, such as pipelines.


  • Cobb Road, from its point of intersection with Highway 16 to the plant entrance(s), will be widened, straightened and covered with additional base material. This will be tarred during construction to reduce dust generation and then paved with asphalt after completion of construction activities.
  • Trucks will be required to meet all safety standards and road load limits.
  • Heavy haulers will be required to assess all bridge crossings for potential capacity upgrades.
  • When working near roadways during transmission construction, pipeline construction and road crossings, workers will adhere to guidelines in Manual on Uniform Traffic Control Devices.

Land Use/Soils

  • Topsoil will be segregated and replaced in pipeline trenches to preserve fertility.

Visual Resources

  • Exterior lighting will be turned off when not needed.
  • All high-traffic on site roads will be paved to prevent dust generation.
  • Along Cobb Road and the site perimeter, existing vegetation will be preserved and protected to the extent practicable.

Cultural Resources

  • The historic properties identified on-site will be avoided by the project.
  • Phase I/II archeological surveys of preferred 161-kV transmission, water supply and construction/emergency line routes have been conducted and no historic properties were found. Should historic properties be identified during construction, they will be avoided or subjected to a Phase II survey.
  • Phase I/II archeological surveys will be conducted along existing transmission lines that will be upgraded in connection with the project.
  • Mitigation of adverse effects will be conducted according to stipulations developed in consultation with the Mississippi State Historic Preservation Officer and of any MOAs prepared for the project.

Environmental Noise

  • If blasting is conducted during construction of pipeline(s), blasting mats will be used to reduce and muffle noise created by the explosions.

Safety and Health

  • Safety features used during construction and operation of pipelines will include 100% X-rays on natural gas pipe welds, x-ray records maintained in accordance with USDOT requirements, and at each end of the pipeline, shut-off valves, which close in the event of an abnormal operating condition, will be installed.


  • The earth quake hazard to ordinary buildings at the proposed project site will be adequately addressed through adherence to the seismic provisions of the Uniform Building Code. Start Printed Page 21192

As discussed in the FEIS, TVA considered additional elective measures for implementation at either of the candidate sites. TVA considered these measures with regard to their necessity for avoidance or reduction of environmental impacts, cost effectiveness and long term benefit to TVA, its customers and the people of Kemper County, and has concluded that these elective measures are not needed. The other best management practices and mitigations to which the agency has committed above are adequate to control the potential for impacts. These elective measures TVA originally considered for surface water and visual resources included use of diversionary berms and/or graveled roadways to additionally reduce erosion from the construction site; implementation of “night sky” lighting techniques and limitation of exterior lighting; use of flat colors in the light to medium cool-gray range on large visible plant equipment; paving of roads to prevent dust generation; planting of evergreen vegetation where needed to complete visual screening along Cobb Road and site perimeter; and adjustment of the plant footprint and construction parking locations to maximize visual screening by existing tree cover.

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Dated: April 16, 2001.

Joseph R. Bynum,

Executive Vice President, Fossil Power Group.

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[FR Doc. 01-10538 Filed 4-26-01; 8:45 am]