Final Environmental Impact Statement-500-kV Transmission Line in Middle Tennessee, 65958-65961 [05-21696]

Agencies

• Tennessee Valley Authority

[Federal Register Volume 70, Number 210 (Tuesday, November 1, 2005)]
[Notices]
[Pages 65958-65961]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-21696]


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TENNESSEE VALLEY AUTHORITY


Final Environmental Impact Statement--500-kV Transmission Line in 
Middle Tennessee

AGENCY: Tennessee Valley Authority (TVA).

ACTION: Issuance of Record of Decision.

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SUMMARY: 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 implement the preferred alternative identified in 
its Final Environmental Impact Statement (EIS), 500-kV Transmission 
Line in Middle Tennessee.
    In implementing Alternative 1, TVA has decided to construct and 
operate the new 500-kV transmission line between Cumberland Fossil 
Plant in Stewart County, Tennessee, and TVA's Montgomery 500-kV 
Substation in Montgomery County, Tennessee. The 38.5-mile transmission 
line would be constructed within Corridor B and on the Cumberland River 
South and Industrial Park Central alternative alignments described in 
the Final EIS.

FOR FURTHER INFORMATION CONTACT: Charles P. Nicholson, Senior NEPA 
Specialist, Environmental Policy and Planning, Tennessee Valley 
Authority, 400 West Summit Hill Drive WT 9B, Knoxville, Tennessee 
37902-1401; telephone (865) 632-3582 or e-mail cpnicholson@tva.gov.

SUPPLEMENTARY INFORMATION: TVA owns and operates a system of 
transmission lines that move electricity throughout the TVA service 
area, which comprises most of Tennessee and portions of six adjacent 
States, and to adjacent utilities. Electric loads on portions of this 
system in the Middle Tennessee area have grown steadily in the recent 
past and are projected to continue to grow. This load growth will soon 
exceed the capability of high-capacity transmission lines serving this 
area. In addition, the loss of two or more of these lines could result 
in the loss of service over a wide area and possible damage to 
generating equipment in at least two locations. Therefore, TVA needs to 
increase transmission capacity in this area.
    TVA published a Notice of Intent to prepare this EIS in the Federal 
Register on November 27, 2001. Two public scoping meetings were held in 
December 2001 and attended by about 50 people. Written scoping comments 
were received from two Federal agencies, two State agencies, and 
several individuals. The Notice of Availability of the Draft EIS was 
published in the Federal Register on April 18, 2003. TVA held two 
public meetings on the Draft EIS in May 2003 and accepted comments 
through early July. During this period, TVA also accepted comments 
received during a series of eight open houses held in June 2003 to 
review potential transmission line routes. Comments on the Draft EIS 
were received from about 200 individuals and several State and Federal 
agencies. TVA also received petitions signed by about 400 individuals 
expressing opposition to various potential transmission line routes. 
The Notice of Availability for the Final EIS was published in the 
Federal Register on July 22, 2005. Although not required, TVA provided 
30 days for comments on the Final EIS. Appendix I of the Final EIS 
contains summaries of and responses to the comments TVA received on the 
Draft EIS.

Alternatives Considered

    TVA uses a detailed, comprehensive siting process when it plans its 
transmission line projects. This is an iterative process that takes 
into account important environmental and cultural resource features 
that become constraints on locating proposed lines. Broad study 
corridors are initially defined and potential line routes are 
subsequently located within the study corridors. Because transmission 
line right-of-ways (ROWs) are much narrower than the study corridors, 
important features that are associated with specific corridors can 
often be avoided when final line routes are selected. It is at this 
point that potential environmental impacts are more fully identifiable.
    TVA identified three alternatives in the EIS.
    Under Alternative 1--Cumberland-Montgomery Study Area, TVA would 
construct and operate a 500-kV transmission line from Cumberland Fossil 
Plant to the Montgomery 500-kV Substation. A new bay and additional 
500-kV breakers would be installed at the Montgomery Substation. Four 
broad alternative corridors for this transmission line were analyzed in 
the EIS. Two of these corridors, the 37-mile Corridor B around the 
south and west side of the city of Clarksville and the 32-mile Corridor 
D around the north of Clarksville, were identified as identified in the 
Draft EIS as preferred by TVA. Following the release of the Draft EIS 
and the subsequent public meetings and open houses, TVA identified 
proposed transmission line routes within Corridors B and D. Alternative 
alignments were developed for some segments of both the Corridor B and 
D routes. Depending on the alternative alignments being considered, the 
Corridor B route is between 38.1 and 38.9 miles long, and the Corridor 
D route is between 31.8 and 37.7 miles long.
    Under Alternative 2--Cumberland-Davidson Study Area, TVA would 
construct and operate a 500-kV transmission line from Cumberland Fossil 
Plant to TVA's Davidson 500-kV Substation in Davidson County, 
Tennessee. A new bay containing a 500-kV breaker would be installed at 
the Davidson Substation. Two broad alternative corridors about 50 and 
51 miles long were analyzed in the EIS.
    Under Alternative 3--No Action, TVA would not construct the 
proposed transmission line. This would result in the risk of loss of 
electric service in a portion of Middle Tennessee with a total load of 
over 4,000 megawatts. There would also be risk of loss of system 
stability and resultant damage to generators at TVA's Cumberland and 
Paradise generating plants. In order to minimize the risk of 
instability, generation would have to be reduced at these plants during 
some system conditions, further exacerbating the risk to service in 
Middle Tennessee.
    The construction and operation of the proposed transmission line 
would be similar under Alternatives 1 and 2. The transmission line 
would use self-supporting galvanized, laced steel structures about 85 
to 125 feet tall. The average distance between structures would be 
about 1,000 feet. The electrical conductors would consist of three sets

[[Page 65959]]

of three cables suspended beneath the structure cross-arms by 
insulators.
    The transmission line would be built on a ROW 175 feet in width. 
TVA would purchase easements from landowners for the new ROW. Because 
of the need to maintain adequate clearance between tall vegetation and 
the transmission line conductors, as well as to provide access for 
construction equipment, most trees and shrubs would initially be 
removed from the entire width of the ROW. Trees outside of the ROW 
which are tall enough to pass within 10 feet of a conductor if they 
fell towards the line would also be removed. Following line 
construction, the ROW would be revegetated with low-growing plants. The 
ROW can be used by the landowner for many purposes that do not 
interfere with the maintenance and operation of the line. TVA would 
periodically inspect and conduct maintenance activities on the 
completed line. The major maintenance activity is vegetation 
management, conducted to maintain adequate clearance around the 
conductors. This would consist of both felling tall trees adjacent to 
the ROW and control of vegetation within the ROW. Management of 
vegetation within the ROW would use an integrated vegetation management 
approach based primarily on mechanical mowing and herbicide 
application.
    Under both action alternatives, TVA would also construct a new bay 
containing a 500-kV breaker at Cumberland Fossil Plant. Depending on 
the transmission line route selected, an additional length of new bus 
work would be needed inside the plant switchyard to connect the new bay 
to a line pull-off structure.
    TVA identified the Alternative 1 as the preferred alternative in 
the Draft EIS. In the Final EIS, TVA identified the Corridor B Route in 
the Alternative 1 Cumberland-Montgomery Study Area, with the Cumberland 
River South and Industrial Park Central alternative alignments, as 
preferred.

Comments on the Final EIS

    TVA received comments on the Final EIS from six State and Federal 
Government agencies and from two individuals.
    Some commenters stated that TVA did not adequately consider all 
viable alternatives to constructing a new 500-kV transmission line, 
including upgrading existing 161-kV transmission lines to 500-kV 
capacity. TVA evaluated four corridors for the Cumberland-Montgomery 
alternative. Corridor C, as described in Section 2.2.2.1.3 of the FEIS, 
offered the potential for using the right-of-ways of several existing 
161-kV transmission lines and interconnecting pieces of new right-of-
way. This corridor was not preferred, and subsequently not evaluated in 
detail in the FEIS, because of its relatively high land use impacts and 
because of engineering considerations. One of these considerations was 
the need to deenergize and dismantle 161-kV lines 18 to 24 months prior 
to the scheduled line completion date. This extended line outage would 
have presented an unacceptable risk to area electrical service. Another 
consideration was that the 161-kV transmission line segments have 
right-of-ways that are 100 feet wide and to accommodate both the 500-kV 
and 161-kV lines, these right-of-ways would have to be expanded to at 
least 175 feet wide. Numerous houses and commercial buildings occur 
along these 161-kV right-of-ways, and the number that would have to be 
purchased and demolished would be considerably greater than for either 
the Corridor B or Corridor D routes. These considerations would also 
apply to other potential routes involving upgrading existing 161-kV 
transmission lines to 500-kV capacity.
    The Environmental Protection Agency (EPA) requested more discussion 
of the suitability of other types of utility rights-of-ways for co-
location of a transmission line. Using non-electric rights of way to 
route transmission lines is often unsafe and avoided for that reason. A 
transmission line can cause induced currents in natural gas and 
petroleum pipelines, resulting in increased corrosion. While this can 
be addressed by retrofitting the pipeline, to do so is expensive. 
Conductor to ground faults from the transmission line are also a 
potential hazard to pipelines. TVA typically does not site transmission 
lines parallel to and within railroad rights-of-ways because of 
interference with railroad communication systems. The need to maintain 
electrical clearance to allow safe train passage also requires that the 
transmission line be some distance from the railroad, resulting in 
minimal overlap of right-of-ways and little savings in the required 
land area.
    The EPA noted that the preferred route and alignments identified in 
the FEIS would have greater impacts on wetlands than several other 
route/alignment combinations analyzed in detail, and asked for more 
explanation of the basis for the selection. This is given below in the 
``Decision'' section. The EPA also questioned how this mitigation ratio 
relates to permitting requirement and noted that the proposed 1:1 
mitigation ratio for impacts to high quality wetlands is likely 
inadequate.
    TVA has not yet submitted a Clean Water Act Section 404 permit 
application to the U.S. Army Corps of Engineers (COE). Based on the 
types of wetlands impacts that would occur (primarily conversion of 
forested wetlands to scrub-shrub and emergent wetlands, and small areas 
of fill for transmission structure foundations and access roads), the 
project will likely qualify for Section 404 Nationwide Permit 12--
Utility Line Activities. It has been TVA's experience that the 
Nashville District COE typically does not require any compensatory 
wetlands mitigation in this kind of situation. The proposed 1:1 
mitigation for impacts to 3.8 acres of high quality forested wetlands 
is amount that TVA believes is appropriate, and if COE requires 
additional mitigation as part of its approval, TVA would comply with 
this requirement.
    The preferred route would affect a total of 23.2 acres of wetlands. 
The majority of this wetland area, 17.0 acres, is comprised of non-
forested wetland types where the level of impacts would be low and 
wetland functionality would not be materially affected. Impacts to the 
affected 6.2 acres of forested wetlands would be different because of 
the long-term conversion of these wetlands to non-forested wetland 
types. While all wetlands share many important functions, forested 
wetlands have additional functions and attributes. As explained in the 
FEIS, 2.4 acres of these forested wetlands were classified as moderate 
quality (Category 2) and 3.8 acres were classified as high quality 
(Category 3). The potential for impacts is greatest for these high 
quality wetlands, and thus they are the focus of TVA's mitigation 
efforts. The 1:1 mitigation ratio would offset the overall loss of 
forested wetland functions that would result from the conversion from 
forested to non-forested wetland types and is consistent with the 1990 
Memorandum of Agreement between EPA and COE on determining mitigation 
under Section 404 guidelines.
    The EPA requested additional discussion on the application of the 
300/1200 foot buffers to reduce exposure to electric and magnetic field 
(EMF) buffers from transmission lines paralleling highways. During the 
line routing process, TVA establishes 300-foot buffers around occupied 
buildings other than schools and 1200-foot buffers around schools. TVA 
does not establish buffers along highways, although in practice 
stretches of highways are buffered from the transmission line due

[[Page 65960]]

to the buffers around buildings adjacent to highways.
    The EPA requested clarification of the environmental justice 
information. TVA considers potential environmental justice effects as a 
matter of policy. FEIS Figure 4-1 shows the percent nonwhite population 
by census block group for the Cumberland-Montgomery study area and 
Table 4-5 lists the actual percentages for the census tracts along the 
Corridor B and Corridor D routes. The individual census tracts were not 
mapped because their small size would make interpretation of the map 
difficult. All of the census block groups with nonwhite populations 
greater than 25 percent are in Montgomery County in the immediate 
vicinity of Clarksville or north of U.S. Highway 79. Nonwhites comprise 
4.7, 26.8, and 19.8 percent of the populations of Stewart County, 
Montgomery County, and Tennessee, respectively. None of the census 
blocks along the Corridor B route in Montgomery County have nonwhite 
populations that exceed county-wide or state proportions. The nonwhite 
population for the one Corridor B census block in Stewart County is 6.9 
percent, higher than the county average and much lower than the state 
average.
    The proportions of the population below poverty level in Stewart 
County, Montgomery County, and Tennessee are 12.4, 10.0, and 13.5 
percent, respectively. None of the census tracts along the Corridor B 
route (listed in FEIS Table 4-5) have poverty rates significantly 
greater than the state rate and three tracts slightly exceed the local 
county rates. Because of the low potential for disproportionate impacts 
to disadvantaged populations that would result from selection of the 
Corridor B route, TVA has determined that measures to mitigate 
environmental justice impacts are not necessary.

Decision

    TVA has decided to implement the preferred alternative identified 
in the Final EIS, Alternative 1 with the Corridor B route and 
Cumberland River South and Industrial Park Central alternative 
alignments.
    Alternative 1--Cumberland-Montgomery Study Area was selected over 
Alternative 2--Cumberland-Davidson Study Area because of the shorter 
line length, lower level of impacts to several natural resources, and 
lower cost. Within the Alternative 1 study area, Corridors B and D were 
selected as the preferred corridors in the Draft EIS based on a 
combination of engineering attributes, natural and cultural features, 
and land use attributes. Among other attributes, these two corridors 
were the shortest and contained the smallest area of forest. The Final 
EIS contains a detailed comparison of proposed line routes in 
Alternative 1--Cumberland Montgomery Study Area Corridors B and D.
    The selection of the Alternative 1 Cumberland-Montgomery Study Area 
Corridor B Route over the Corridor D route was based on several 
factors. While shorter and with less impacts on wetlands and less 
forest fragmentation, the Corridor D Route would require the relocation 
of more residences and have a greater impact on planned residential and 
commercial development. A portion of it would have been located on or 
very close to Fort Campbell Military Base, potentially interfering with 
aircraft operations. It would also have affected the Ringgold Mill 
Complex historic site.
    The Cumberland River South alternative alignment of the Corridor B 
Route was selected over the Cumberland River North alignment in order 
to avoid ongoing residential development and land suitable for future 
development. The selected alignment also avoids an agricultural area 
with extensive underground drainage that the Cumberland River North 
alignment would have crossed.
    At the eastern end of the Corridor B Route, the Industrial Park 
Central alternative alignment was selected over the Industrial Park 
East and Industrial Park West alignments because of its shorter length 
and reduced amount of right-of-way to be acquired. The Industrial Park 
Central alignment also runs parallel to and shares part of the right-
of-way of an existing 500-kV transmission line, further reducing the 
amount of new right-of-way to be acquired and land use impacts.
    In reaching this decision, TVA has carefully considered the 
comments and concerns voiced by the public. Based on the comments TVA 
received during the scoping and EIS review processes, the effects on 
landowners from having the transmission line built on or near their 
property was a major concern. TVA has attempted to minimize these 
impacts during the transmission line siting process, and the selected 
route affects slightly fewer landowners than the Corridor D Route. It 
also would require fewer residential relocations and have fewer 
buildings within 300 feet of the line. Commenters also expressed 
concerns about impacts to cultural and natural resources. The selected 
Corridor B Route would have less impact on cultural resources than the 
Corridor D Route, and the Tennessee State Historic Preservation Officer 
has concurred with TVA's determination that the Corridor B Route would 
not adversely affect any archaeological or historic sites eligible for 
or listed in the National Register of Historic Places. The U.S. Fish 
and Wildlife Service has concurred with TVA's determination that the 
Corridor B Route would not adversely affect species listed under the 
Endangered Species Act.

Environmentally Preferred Alternative

    Alternative 3--No Action is the environmentally preferred 
alternative because the impacts associated with constructing and 
operating a high voltage transmission line would not occur. This 
alternative, however, would result in the risk of the loss of 
electrical service to a large area of Middle Tennessee with a total 
load of over 4000 megawatts and is considered unreasonable. The loss of 
this electrical service would result in social and economic impacts.
    Of the two action alternatives, Alternative 1--Cumberland-
Montgomery Study Area is environmentally preferred over Alternative 2--
Cumberland-Davidson Study Area. Potential transmission line routes in 
the Alternative 1 study area average about 20 percent shorter than 
those in the Alternative 2 study area and would require the purchase of 
less right-of-way and have less impact to forests, wildlife 
populations, and streams.
    Neither of the two Alternative 1--Cumberland-Montgomery Study Area 
transmission line routes studied in further detail, the Corridor B 
route and the Corridor D route, is clearly environmentally preferable 
over the other. Of the various alternative alignments for the selected 
Corridor B route, the Cumberland River North alignment is 
environmentally preferable over the selected Cumberland River South 
alignment because of less impact on wetlands, ecologically significant 
sites, and forested stream crossings. None of the Industrial Park 
alternative alignments are clearly environmentally preferable over the 
others.

Environmental Commitments

    For the reasons discussed in the Final EIS and summarized here, TVA 
is committing to the following measures to avoid, reduce, or mitigate 
the potential environmental impacts associated with these actions:
     In order to reduce potential impacts to groundwater, TVA 
will not apply herbicides aerially along the ROW between a point about 
0.4 miles northeast of Highway 12 (at transmission line structure 136) 
and the Montgomery 500-kV Substation. The

[[Page 65961]]

use of fertilizers will also be avoided or minimized in this area.
     In order to reduce the impacts to wetlands, TVA will 
provide compensatory mitigation for 3.8 acres of high quality forested 
wetlands at a 1:1 ratio. Compensatory mitigation measures include, but 
are not limited to, the purchase of credits in an existing mitigation 
bank within the hydrologic unit for the project area or an adjacent 
hydrologic unit, and restoration of forested wetlands in or adjacent to 
the project area hydrologic unit by TVA or through an in-lieu-fee 
agreement with a state agency or private conservation organization. A 
higher mitigation ratio will be used if required by the Section 404 
permit issued by the Corps of Engineers.
     No invasive plant species will be planted on the new ROW.

    Dated: October 20, 2005
W. David Hall,
Vice President, Electric System Projects.
[FR Doc. 05-21696 Filed 10-31-05; 8:45 am]
BILLING CODE 8120-08-P