20000846 Ver 3_More Info Received_20091120

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PIEDMONT TRIAD
AIRPORT AUTHORITY
November 16, 2009
Mr. John T. Thomas, Jr.
U.S. Army Corps of Engineers
Wilmington District
Raleigh Regulatory Field Office
3331 Heritage Trade Drive, Suite 105
Wake Forest, NC 27587
Re: Piedmont Triad Airport Authority
USACE Permit No. 200021655
Tree Removal - Line of Sight Project
Dear Mr. Thomas:
The Piedmont Triad Airport Authority ("PTAA") hereby re-
quests that the U.S. Army Corps of Engineers ("USAGE") make the
necessary modifications to the above-referenced permit to allow
PTAA to proceed with a tree cutting project, as discussed below,
within certain preservation tracts (the "Preservation Tracts")
that were set aside by PTAA at the Piedmont Triad International
Airport (the "Airport") in accordance with the above-referenced
permit. The purpose of the project is to clear the Line of Sight
("LOS") between the Air Traffic Control Tower ("ATCT") at the
Airport and new Runway 5L/23R and its associated taxiways, as
required by the applicable regulations of the Federal Aviation
Administration ("FAA").
All reasonable efforts have been made to avoid and minimize
impacts to the Preservation Tracts. Although PTAA does not
believe the wetland function of the Preservation Tracts will be
adversely affected, PTAA proposes the additional wetland mitiga-
tion described in this letter due to the temporary loss of forest
cover that will occur within the affected areas.

tti .

Min'. John T. Thomas, Jr.
Page 2
November, 16, 2009•
1. Need to Clear the LOS.
PTAA is now completing the construction on new Runway 5L/23R
at the Airport, along with Taxiway H (running parallel to
the new runway along its entire length) and Taxiway E (per-
pendicular to the new runway and connecting the new runway
with the existing airfield at the Airport). The cost of the
new runway and taxiway system is approximately $155,000,000.
The new runway and taxiways are nearing completion. How-
ever, the LOS from the ATCT to the new runway and taxiways
is currently obscured by trees growing at various locations
within the Preservation Tracts (portions of Preservation
Tracts T through X in PTAA's Conservation Easement). This
obstruction prevents a clear view of the runway and its
traffic pattern. Under applicable FAA requirements, the
new runway and taxiways cannot be opened to traffic until
the trees obstructing the LOS have been completely cleared.
The FAA requirement for maintenance of an unobstructed LOS
between the ATCT and the runways and taxiways at an airport
arises from the logical need for air traffic controllers to
have a clear view of aircraft arriving and departing from
the airport and of the airfield areas that the ATCT is re-
quired to monitor. This requirement is expressed in FAA
Advisory Circular 150/5300-13, Change 6, which states as
follows:
"b. Clearance Requirements. ATCT sites must meet
these requirements:
(1) There must be maximum visibility of the air-
ports's traffic patterns.
(2) There must be a clear, unobstructed and di-
rect line of sight to the approaches, to all
runways or landing areas, and to all runway
and taxiway surfaces...."
Section 201 of FAA Order 6480.4A further provides that an
airport's ATCT cab (i.e. the lookout at the top of the ATCT)
must have "an unobstructed view of all controlled movement
Mr. John T. Thomas, Jr.
Page 3
November 16, 2009
areas of an airport, including all runways, taxiways, and
any other landing areas...."
As discussed below, PTAA has consulted extensively with the
responsible officials of the FAA and has been informed that
no exception can be made for tree growth within the LOS for
the new runway system.
2. Past Consideration of LOS Issues.
In the initial design of the runway project, careful consid-
eration was given to LOS issues. The elevation for a por-
tion of the runway system was raised in the initial design
to provide a clear LOS to the new runway system. However, a
further elevation of the final grade would have resulted in
a larger project footprint within jurisdictional areas and
would not have complied with the requirement for PTAA to
minimize the wetland impacts of the runway project.
The need for clearing trees within the Preservation Tracts
to comply with FAA requirements (both initial cutting and
subsequent maintenance) was anticipated when PTAA granted
the conservation easement to USACE for the affected tracts.
That easement reserved to PTAA the right to take such action
as might be necessary "to comply with the regulations and
directives of the Federal Aviation Administration," includ-
ing "the right to remove objects of natural growth... on any
part of the Property that exceed the heights approved from
time to time by the Federal Aviation Administration, and the
right to eliminate any other conditions on the Property that
would interfere with or be a hazard to the flight of
aircraft... or that would otherwise constitute an airport
hazard."
Although the need to cut trees within the Preservation
Tracts was foreseen, the required cutting has increased in
the years since the original permit decision. PTAA sub-
mitted its Stream and Wetland Mitigation Plan to the USACE
in December, 2001. Eight years of tree growth have occurred
since then. The extent of that growth was unpredictable and
dependent on several variables, including weather, tree
species and soil types. It was not possible for PTAA to
determine the tree cutting that would actually be required
Mr. John T. Thomas, Jr.
Page 4
November 16, 2009
until this year, when the time for clearing the LOS had
arrived and PTAA could identify the obstruction that had to
be removed.
There has also been a considerable delay in the runway con-
struction schedule from what was anticipated at the time of
the permit decision. At that time, the construction of the
runway was expected to begin in 2004, and the EIS for the
runway project projected that the runway would be opera-
tional in 2005. If the runway construction had been com-
pleted according to the original schedule, less growth would
have occurred before the initial clearing of the LOS, and
the maintenance cutting that would have been required in
subsequent years would have proceeded more gradually, with
fewer trees affected at any one time. Due to the delay in
the runway construction, the cutting that is now required
is more extensive than could have been anticipated when the
permit was issued.
3. Tree-Cutting Proposal.
To clear the LOS and provide a margin against future growth,
PTAA will set a maximum elevation for growth within the
Preservation Tracts at 10 feet below the LOS (the "Clearance
Threshold"). The areas within the Preservation Tracts where
the tree canopy exceeds this threshold are identified in
blue on the enclosed Drawing E-1. Only nine acres of wet-
lands are included in the blue areas. The blue areas also
include seven acres of upland buffers.
PTAA proposes to cut all mature trees within the blue areas
at the ground. Upon completion of the cutting, PTAA will
replant the blue areas with a mix of oaks and other late-
succession tree species reflecting a reference site in a
mature, bottomland forest. This approach will accelerate
the growth of the most desirable species within the affected
areas and will result in a transition to an oak-dominated
forest.
4. Tree Cutting Outside the Preservation Tracts.
Mr. John T. Thomas, Jr.
Page 5
November 16, 2009
In addition to cutting within the Preservation Tracts, PTAA
will also cut trees in four acres of jurisdictional wetlands
outside of any conservation easements, as identified in
orange on Drawing E-1. This cutting results both from the
need to clear the LOS and, in some areas, to comply with
height limits under Part 77 of the FAA regulations. As in
the case of the cutting within the Preservation Tracts, the
cutting in the orange areas will also provide a 10-foot
margin against future growth. All mature trees within the
orange areas will be cut at the ground, and the orange areas
will then be replanted with oaks and other late-succession
tree species, as in the case of the blue areas within the
Preservation Tracts. Since no dredging or filling will
occur within these wetlands, no USACE action should be
required to authorize cutting within the orange areas.
5. Impacts of the Tree Cutting Project.
As indicated above, the tree cutting project will only im-
pact nine wetland acres within the conservation easements
granted by PTAA. The balance of PTAA's Preservation Tracts,
colored in green on the enclosed drawings, will not be af-
fected by this project. The green areas include the largest
Preservation Tract in PTAA's mitigation plan and the preser-
vation areas with the most mature hardwood forest, which lie
along Brush Creek downstream from Taxiway E. In addition,
PTAA's wetland restoration and creation projects downstream
from Taxiway E, and also along Horsepen Creek, have been
planted with trees using a bottomland hardwood forest refer-
ence site, and will eventually develop into forested wet-
lands comparable to the Preservation Tracts.
6. Avoidance and Minimization of Resulting Impacts.
PTAA has consulted with FAA traffic control officials, who
confirm that no exceptions can be allowed for tree growth
within the LOS for the new runway system. While the FAA
contemplates the eventual construction of a new ATCT at PTAA
which will be high enough to raise the LOS above any tree
growth and thereby eliminate any need for further cutting,
the FAA cannot advance the construction of the new ATCT in
time to avoid cutting within the Preservation Tracts.
Therefore the present need to clear the obstructing trees
Mr. John T. Thomas, Jr.
Page 6
November 16, 2009
from the LOS is unavoidable, both to comply with FAA regula-
tions and to ensure traffic safety.
PTAA has taken all reasonable and practical steps to mini-
mize the impact of the tree cutting, as follows:
¦ During the summer of 2009, PTAA cut the trees that were
obstructing the LOS in upland areas above the Preserva-
tion Tracts. This initial cutting provided a better
view of the remaining obstruction so that the cutting
that would be needed within the Preservation Tracts
could be more clearly identified.
¦ In setting the Clearance Threshold 10 feet below the
LOS, PTAA has chosen what it believes to be the most
desirable balance between limiting the area to be cut
(by setting the threshold at a relatively high level)
and limiting the need for future cutting (by providing
a margin for new growth within the preservation areas).
The allowance of a margin for new growth increases the
possibility that a new ATCT will be in place before any
significant cutting is required in the future.
¦ The proposed cut zones (blue areas on the enclosed
drawings) have been drawn as narrowly as possible to
ensure that cutting will be strictly limited to the
locations where trees actually exceed the Clearance
Threshold and that the remaining areas will not be
disturbed. The irregular boundaries of the blue areas
indicate the care with which this delineation has been
made.
¦ The areas to be cut have been divided by PTAA's engi-
neers into multiple plan sheets specifying, in detail,
the most desirable ingress and egress routes for the
contractor's equipment within preservation areas.
These routes have been carefully designed to avoid any
unnecessary disturbance, and these routes will be
seeded with an upland or wetland seed mix, as appro-
priate, after the removal of the contractor's
equipment.
Mr. John T. Thomas, Jr.
Page 7
November 16, 2009
¦ PTAA will follow the Vegetation Management Plan en-
closed with this letter.to minimize ground disturbance
from the cutting, to limit any impact on vegetation and
wetland function resulting from the cutting, and to
encourage rapid regeneration of desirable forest growth
after the cutting is completed.
¦ The cutting is scheduled for late this year, when the
sap in the remaining trees has descended and the re-
maining trees will be less vulnerable to any damage
that might result from being struck by falling trees
during the tree-cutting operation.
¦ The upland and wetland areas within the affected acre-
age will be left in a vegetated state following the
cutting, and the forest within such areas will regen-
erate as a result of the replanting of those areas by
PTAA. The wetland character and function of the wet-
lands will be preserved.
7. Additional PTAA Mitigation.
Although PTAA does not believe that the proposed tree-
cutting project will have a significant impact on the qual-
ity or function of the wetlands within the Preservation
Tracts, PTAA acknowledges that the 5:1 credit that was
granted in the permit for the preservation sites exceeds the
normal credit for preservation acreage, and was based, in
part, on the forest cover within such sites. To compensate
for the temporary loss of forest cover in the nine wetland
acres within Preservation Tracts, PTAA proposes to amend its
wetland mitigation plan for Permit No. 200021655 to add 2.6
acres of riparian wetland restoration at the Causey Farms
site, where PTAA has provided a portion of its existing
mitigation. This site is within the Haw River Basin (Hydro-
logical Unit 03030002), the same basin as the impacts from
the runway project. The Causey Farms site has been planted
with an appropriate mix of trees, which have already been
established successfully. PTAA has received a commitment
from Restoration Systems, the developer of the Causey Farms
project, to provide the additional mitigation.
Mr. John T. Thomas, Jr.
Page 8
November 16, 2009
PTAA appreciates your willingness to work with PTAA to clear
the LOS for the new runway and taxiway system and to achieve
compliance with both FAA and USACE regulations. If you would
like additional copies of the enclosed drawings or any additional
information or supporting documentation, please let me know.
Sincerely,
PIEDMONT TRIAD AIRPORT AUTHORITY
By:
K vin J. Baker
Assistant Airport Director
KJB:bc
Enclosures
cc: Mr. Justin McCorcle
Asst. District Counsel
USACE, Wilmington District
Ms. Cindi Karoly
Ms. Sue Homewood
N.C. Division of Water Quality