20151065 Ver 1_USACE Correspondence_20140717

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STATES OF �• • • -
Regulatory Division/1200A
DEPARTMENT OF THE ARMY
WILMINGTON DISTRICT, CORPS OF ENGINEERS
69 DARLINGTON AVENUE
WILMINGTON, NORTH CAROLINA 28403-1343
Action ID: SAW -2012-01547
Mr. Kevin J. Baker, P.E.
Piedmont Triad Airport Authority
1000A Ted Johnson Parkway
Greensboro, North Carolina 27409
Dear Mr. Baker:
July 17, 2014
N.C. Dep. of ENR
JUL 2 120% J =
WINSTON-SALEM
REGIONAL OFFICE
Please reference your June 26, 2014 letter (received June 27, 2014) requesting
concurrence for alternatives for the proposed Cross -Field Taxiway at the Piedmont Triad
International Airport (PTIA) in Greensboro, Guilford County, North Carolina. Further, please
reference the meeting pertaining to regulatory requirements for the above referenced project held
at PTIA on June 9, 2014 involving representatives from the U.S. Army Corps of Engineers
Wilmington District (Corps), North Carolina Division of Water Resources, and Michael Baker
Engineering, Inc. Lastly, please reference the Preliminary Draft Environmental Assessment
(PDEA) Revision 1 for the Cross -Field Taxiway and Site Development Projects at PTIA, dated
March 14, 2014 (received June 11, 2014).
The primary requests of the June 26, 2014 letter were for Corps concurrence that the
proposed taxiway alignment is the only practicable. alternative for the proposed project and that
the North Carolina Department of Transportation (NCDOT) can proceed with construction of the
Taxiway Bridge as proposed. As discussed during the June 9, 2014 meeting the Corps has no
mechanism outside of the. Corps/NCDOT/FHWA/NCDWR Section 404/NEPA Merger Process
to choose a Least Environmentally Damaging Practicable Alternative (LEDPA) prior to permit
application. Further, as construction of the taxiway bridge is purported to take place completely
in uplands, in no way impacting Waters of the U.S., the Corps has no authority to determine if
the NCDOT.can begin bridge construction. As noted in the meeting, there is inherent risk in
constructing an integral component of a larger project when other aspects of that project will
require Corps authorization. In this case, no impacts to Waters of the US are currently
authorized for either the Cross -Field Taxiway or the NCDOT project I-5110 above which the
taxiway bridge is proposed to be built. It should be noted, however, that LEDPA concurrence
was reached for I-5110 (Action ID: SAW -2011-00317) on June 14, 2012 via the Merger process.
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IVA
Although we are unable to satisfy your request, we will endeavor to provide comments
based on the information you provided in your letter that may prove useful upon submitting your
permit application:
1) The engineering and safety constraints discussed for each alternative appear reasonable
for determining the general location of the proposed taxiway;
2) Your letter states that the alternative of shifting the taxiway to the northeast, without
moving the existing Airport Surveillance Radar (ASR), would not result in any
"meaningful" reduction in stream impacts. Given that we can only authorize the LEDPA
of any project, an alternative that minimizes stream impacts even slightly could
potentially be considered meaningful in our permit application review. As such, smaller
shifts in -taxiway location should be evaluated, including specific impact numbers, for
minimization purposes;
3) The PDEA indicated that the ASR will be relocated as part of this project. However,
your June 26, 2014 letter appears to use the ASR as an alternative constraint. This point
should be clarified, especially if minimization of stream impacts could be achieved by
shifting the taxiway 100 feet northeast of the proposed location.
4) An alternative that avoids impacting any waters of the US, such as spanning the
stream/wetland system with a bridge (i.e. no discharge of dredged or fill material in
Waters of the US), was not discussed in the June 26, 2014 letter or the PDEA. However,
this alternative would eliminate the need for Corps authorization for the taxiway and is
required to be evaluated in the permit process.
5) As discussed during the June 9, 2014 meeting the taxiway itself does not have
independent utility and thus the Corps cannot authorize it singly. As such, any permit
application must also include at least a conceptual design of the receiving facility
(expansion area). Further, if any impacts to Waters of the US are proposed for this
facility then you must show avoidance and minimization in accordance with the
404(b)(1) guidelines.
6) The PDEA evaluated several offsite alternatives for the expansion area as described.
However, other than for the preferred alternative it did not provide estimates of impacts
to Waters of the US; practicability was the primary reason for this lack of information.
Alternative 3 would require higher but not dissimilar property acquisitions/relocations
than the preferred alternative. The PDEA mentioned that Alternative 3 is not practicable
due to a future planned parallel runway, however this plan is not shown in the document.
The Corps would not necessarily consider this alternative impracticable based on the
information provided in the PDEA, and thus potential Waters of the US impacts for this
alternative should be shown for comparison purposes.
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A
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7) The PDEA notes that US Fish and Wildlife Service concurrence for threatened and
endangered species was received for the taxiway area. Did the threatened and
endangered species survey and concurrence letter also cover the larger preferred
alternative expansion area?
Hopefully you have found this information useful. If you have any questions contact me at
[phone] ext. 30 or David.E.Bailey2 a,usace.army.mil.
Sincerely,
David E. Bailey
Project Manager
Copy Furnished:
Ms. Sue Homewood & Mr. Dave Wanucha
Division of Water Resources
North Carolina Department of
Environment and Natural Resources
585 Waughtown Street
Winston-Salem, North Carolina 27107
Ms. Karen B. Capps, P.E.
NCDOT Design Build Office
Transportation Program Management Unit
1595 Mail Service Center
Raleigh, North Carolina 27699-1595
Messrs. Richard Darling and Larry Allen
Michael Baker International
8000 Regency Parkway, Suite 600
Cary, North Carolina 27518
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PIEDMONT TRIAD AIRPORT AUTHORITY
June 26, 2014
U.S. Army -Corps. of -En gii
neers
Wilmington District
Raleigh Regulatory Field Office
3331 Heritage Trade Dr., Suite 105
Raleigh, NC 27587
Attention:
Subject:
Mr. Andrew Williams
Mr. David Bailey.
RECEIVED
N.C.Dept. of ENR
JUN 3 0 2014
Winston-Salem
R ionalOffice
North Carolina Department of Environment
and Natural Resources, Division of Water
Resources, Winston-Salem, Regional Office
5.85 Waughtown St.
Winston-Salem, NC 27107
Ms. Sue Homewood
Mr. Dave Wan icha
Alternatives .Analysis 'for proposed Cross -Field Taxiway at - Piedmont' Triad
International Airport, Greensboro;.Guilford.County
The Piedmont Triad Airport -Authority (PTAA), anticipates :applying ;for- an Individual Permit and
Water Quality Certification under Sections 404 and 401 of the= Clean Water Act and
15ANCAC 2H-.0500, and for an. authorization, if required,,under-the Jordan Lace. Buffer Rules
(15A 1,4 -CAC 213' :0267),, to. construct and operate a proposed, new Cross=Field Taxiway, over
future Interstate Highway I-73 at the Piedmont Triad International Airport (PT1A). Pending the
submission of such applications; PTAA is requesting regulatory concurrence with the following
Taxiway 'alternatives analysis, -in order to facilitate the location .and construction of the bridge
component of the�project by the North Carolina Department of Transportation•,(NCDOT). This
proposed bridge is .the first necessary part of the Taxiway project but will -not itself impact
jurisdictional- resources. This .alternatives- analysis was completed in order to ,determine the
placement of the bridge based on environmental and practical constraints on the taxiway
location.
The Taxiway project 'is ,currently included in the Preliminary Draft Environmental. Assessment
(PDEA, provided separately) that has been prepared for the Federal Aviation Administration
(FAA), under the National, Environmental Policy Act. Jurisdictional resources within the
Taxiway project area (as' well'as the approximately'569-acre'potential development area on the
North side of I=73) have been preliminarily verified by the- United States Army Corps �of
Engineers (USACE,. Action ID- SAW -2012-01547 dated July 10, 2013). The applicability of this
determination to the state Mitigation Rules .[15A NCAC 211.0506 (h : and, the Jordan .Lake
Riparian Buffer Rules was determined by the North Carolina 'Department of Environment and
1000A Ted Johnson Parkway • Greensboro,, North Carolina 27409 =• Phone: 336:665.5600 • Fax: 336,665.1425

USACE imd NCDENR
June 26, 2019
Page 2 9f 6
NaturalResources (NCDENR) Division of Water Resources, (DWR) in correspondence dated
January 17, 2013.
Estimated Project Impacts
The proposed Taxiway, alignment is shown on the- -enclosed ' Figure 1 ("Cross Field Taxiway
Alternatives"), with the proposed Taxiway Bridge d'epicted'in green.. Due. to a required crossing
of -an unnamed tributary to Brush Creek, as shown ori .Figure 1, the proposed Taxiway may
impact approximately. 232 linear feet (11) of perennial stream channel, -and 1181.£ of
intermittent stream channel, and may also impact approximately 21.,076 square feet ,(&2) ;of
Zone Ij; and 11,662 ft? Zone 2 (0.75 acre total) of Jordan Lake riparian buffer along the .banks of
the stream. (Since our June 9 meeting,, we have examined -the stream impacts of the proposed
Taxiway -more closely, and determined that they would be fewer .than. indicated at the meeting.)
This jurisdictional channel .rims parallel to, and Northwest of, existing Bryan Boulevard and
flows in a Southwest direction to a largerwetland/stream complex. As discussed below,
minimization of unavoidable impacts will .continue to be explored to the extent practicable
through.final project design, and the potential impacts have already -been mitigated.
Project.Purpose and Need
As described in the?DEA; the Taxiway.is needed .to provide airfield access to the, approximately
569=acre development site on:the north side of the future -I=73. Developmentof airfield access•to
the 569=acre site is needed to:
m provide suitable sites with airfield access for new aviation -related development
o provide development opportunities f6vuse of idle land
o meet schedule needs of potential aviation tenants
As emphasized in the PDEA, it is critical to the Project Purpose and Need for ,PTAH to -prepare
sites,. with. ;airfield access, in advance of having, a tenant for the sites, since potential tenants
require sites to be available within a short time frame to meet their scheduling, needs.
Avoidance, of Impacts
The -connection of the 569 -acre site to existing airfield facilities can only be achieved by building
a taxiway across the I-73 segment which is being constructed .at 'the -Airport by -NCDOT
(Transportation linprovement P-roject I-51-10). The profile for the NCDOT project is constrained
in two locations:
1. On the east side of the 1-51.10 project, the project; ties into Bryan Boulevard at the
Airport/Old Oak Ridge Road. Interchange. This sets the starting elevation of the
I-5110 profile.
2. The I-5110 alignment, is required to span- over highway NC 68. The vertical
clearance of :the I-5110 roadway over NC 68 sets the elevation of I-5110 on the west
side of the highway project.

USACE and NCDENR
June 26, 2019
Page 3'of 6
The profile- from the existing Airport/Old Oak Ridge Road Interchange to the future Taxiway
Bridge has been set to its lowest possible elevation based on, the maximum..allowable slopes of
the roadway profile between the Airport Interchange and NC 68..
The'Taxiway and Bridge have been carefully positioned to meet' the constraints -imposed by the
highway profile and,. at the same time, to provide for the safe and efficient operation of the
'Taxiway:
The Taxiway must cross over the highway, along the Taxiway Bridge, at a Height of
at least 17 ft. above the ,highway pavement. To clear this height, the Taxiway must
rise 'from its starting elevation of 856.81 ft. Mean .Sea Level -(MSL) at -fittum
Taxiway G (see "Proposed Cross. Field Taxiway," on Figure 1) to a minimum
elevation of 896:58 fL MSL at. the Taxiway Bridge, or a total climb of 39.77:ft. The
maximum -grade for •a taxiway at an air- carYier airport is 1.5% per FAA Advisory
Circular (AC) 1.50/5300-13A. After:a required -transition to the uphill grade, the
proposed Taxiway must, be tong enough to •climb" the necessary 39.77 ft. at 'the 1.5%
grade. The,pioposed'Taxiway runs:a sufficient distance for the climb, but -the margin
is minimal -for shifting the location of the Taxiway and still achieving the necessary
clearance. above, the road.
® The Taxiway must be straight for safe. and efficient operation. The FAA recommends
minimizing changes in direction along.a taxiway to reduce the risk -of aircraft running
off the paved. ,surface during, reduced visibility. 'In addition, curving the Taxiway
would not -reduce stream impacts unless the curve were -to the northeast, as illustrated
in red on Figure .1. This alignment -would route ,the Taxiway behind the.elevated site
for the Airport.Surveillance Radar (ASR):(as.shown in blue on -Figure 1) which would
block the Line -of -Site from the Air Traffic Control Tower (ATCT,) to- the Taxiway:.
Due to this: obstruction, pilots would. not have the assistance of the ATCT in moving
along the Taxiway, and their own view down: the taxiway would. also be obstructed by
the ASR, and taxiway curve,. These iinpediments 'would create an aircraff hazard
because pilots would not be able to. see aircraft -approaching from the opposite
direction until .they had already entered the taxiway and were facing- the -opposing
traffic. If, in the future, the ASR were relocated, the Line -of -Site issue would likely
remain,,since the ASR would- not be relocated unless the site were needed for tenant
facilities, which could also block both the ATCT's .and the pilot's Line -of -Sight.
'The Proposed. Taxiway meets -the foregoing height and safety criteria; and, as shown below, also
avoids unnecessary impacts to jurisdictional waters: While, the NCDOT design -build team. has
made some adjustments in the highway design (as reflected on Figure 1), these -changes have not
materially altered the constraints imposed by flip original plan .but merely allow for the -original
concept to be achieved at a reduced:cost.

USACE a)?dNCDENR
June 26, 2019
Page 4 oft'
The PTAA has carefully considered. a fill range of options to determine, if there are any
practicable alternatives to the proposed Taxiway alignment that would have fewer impacts to
jurisdictional waters. None of these options achieves the Project Purpose 'and Need or. reduces
the impacts:
Shift to the Southwest
This concept -is illustrated, in yellow on.Figure 1. The limits for shifting the Taxiway to
the Southwest, and still providing for adequate clearance above the highway, are very
constrained because the highway climbs at a steeper angle than the 1.5% taxiway limit.
Even within -this narrow range, the combined impact -to ,perennial and intermittent, streams
is not appreciably reduced and the impacts of this alternative are greater, to wetland, and
perennial stream channel, and to riparian buffer, than in the case of the proposed
alignment. (See :corrected impacts on Figure- L)• Any further -shift to the Southwest
merely moves the impacts .closer to wetlands and higher quality perennial streams. The
decreasing elevation of the stream system .and adjacent topography as the stream flows
Southwest would, also increase the height` of -the Taxiway above the stream and require a
wider embankment' with greater impacts. Therefore shifting the Taxiway, to the
Southwest, within the feasible limits, .increases rattier than reduces impacts and isnot .an
acceptable alternative.
Shift -to the Northeast
As illustrated on. Figure 1, the slope of the proposed Taxiway on. its Northeast side
already abuts the ASR site; .and the Taxiway .cannot 'be shifted at ,all in this direction
without relocating the ASR. Even if the ASR were relocated,.a shift of the Taxiway to
the Northeast:of as little as 100 ft. would reduce the Taxiway length to the point that the
Taxiway would not climb sufficiently above- the highway. Any 'such .shift would not
avoid a stream crossing .and would not result in any meaningful reduction in -the stream
impacts.
Curved Taxiway
PTAH has examined this alternative, despite PTAA's belief that a straight alignment is
required for- the safe and efficient operation of the Taxiway. As pointed: out above, the
only way a curved Taxiway would, avoid. a ,s'tream crossing is by following the alignment
to the Northeast that is illustrated in red on Figure 1. This alignment would result in the
Zine -of -Sight .issues .discussed above and create a hazard for traffic along the Taxiway.
Furthermore, even measured along the curve, this aligmnent would not have sufficient
length for the necessary climb above the -highway, either before or after the adjustments
made by Ahe design -build -team. This 'limitation excludes this alignment from further
consideration.
For :the reasons discussed above, there is no -alternative alignment for the Taxiway that is- both
feasible and that would :reduce stream, wetland, or' buffer impacts: resulting from the proposed
alignment. The proposed alignment, in turn, sets the location,of the Taxiway ,Bridge at the
Iocation shown in green. on Figure 1.

USACE and AFCDENR
June 26, 201 d
Page 5 of 6
The PDEA summarizes consideration of alternative locations -for the proposed expansion of the
Airport, including areas southeast, south, southwest .of PTIA, and, a combination of non-
contiguous sites. None ,of these locations mee'ts'the Project Purpose and Need or avoids the need
for the proposed Taxiway.
'Impact Minimization
Although PTAA is not seeking ,a determination, at this- time, as to the adequacy of minimization
efforts,.'PTAA will minimize potential adverse:.effects of theproject .through measures that are
consistent with FAA requirements and Section 404(b)(1) guidelines.
The width of the taxiway full-strength pavement, within the proposed -aligmnent, 'is ,75 c. (for
Group V aircraft) with -iniinimum 35 -ft. shoulders on each side, consistent with FAA
AC 150/530043A. 'The Taxiway Safety Area (TSA) extends beyond the: shoulders with a
minimum, width, centered on the, taxiway centerline, of .214 feet. Transverse grades- are
maximized, within this width but must not exceed ,3%. -Maximum slopes beyond the TSA have
been, set at 3:1 to allow. for appropriate maintenance within the Air Operations Area.. The
proposed Taxiway site and embankment are thus fixed at the locations depicted on Figurc :1 with
no feasibility for .alternative locations or dimensions that would fulfill, the Project Purpose and
Need or reduce environmental .impacts.
Conmpensatory Mitigation.
To the extent necessary to compensate for unavoidable, minimized impacts to jurisdictional
stream channel and .riparian buffer, PTAA will dedicate appropriate components of the
successfiilly completed 1,123 l:f restored stream channel and adjacent riparian buffer at the
Causey Farm mitigation site, which PTAA has purchased but has not applied to -any specific
impacts -at PTIA.This mitigation -credit was originally purchased to compensate for impacts
,anticipated.from construction. of the Runway 5R Safety Area and related improvements (USACE
Action TD SAW -200641354; DWR File''0.6-1632): This project; however, has been, put 'on
indefinite hold and rather than extend the Section 404 =and 401 permits that were issued for this
project, PTAA has elected to abandon them. Therefore, the mitigation -is already in place. for the
Taxiway project stream and buffer impacts, and'the credits needed for full compensation will be
applied to the project.
Stornrwater
Pursuant to N.C:G.S. 143-214.7(c4), the proposed Taxiway will: provide for overland stormwater
flow that -promotes infiltration and- treatment of stormwater into grassed buffers, shoulders, and
,grassed swales and is.permitted putsuarit to State post -construction stormwater.requirements.
Prior -to the conunencement of 'construction, a Sedimentation and Erosion Control Plan for the
project will be- submitted to NCDENR, and PTAA will obtain the applicable Sedimentation and
Erosion Control ,Permit and accompanying NPDES Construction Permit. Potential .temporary
impacts to surface water quality, as a result of the construction activities will be effectively

USACE and NCDENR
Ane26, 2019
Page 6 of 6
mitigated through adherence to the approved Sedimentation and Erosion Control Plan and other
permit requirements, as well, as through compliance with FAA AC 150/5370-10B.
Cumulative Impacts
The -cumulative effects of the Taxiway project and related site development are- addressed in -the
PDEA,.'which provides a detailed qualitative analysis of cumulative impacts consistent with the
DWR April 2004 Internal Policy. The water quality related cumulative .impact .potential of the
site development will be addiessed'by PTAA through :its Water Supply Watershed Management
and Protection Rules, :as well as by .the applicable .requirements of the Jordan. Lake Rules and any
additional mitigation measures that. are adopted, in the final EA.
Requested Action
We are 'Hereby requesting:, (1) the concurrence of -the USACE and .DWR that, for purposes of
PTAA's •upcoming Section 404/401- Permit application; and any necessary authorization under
the Jordan Lakc Rules, there are no practicable alternatives -to the construction of the, Taxiway
other than in its .proposed alignment as shown on Figure 1, and (2) the concurrence :of -the
USACE and. DWR that NCDOT -may proceed with the construction of the Taxiway Bridge :at its
proposed location. Please feel, free to contact me, Alex Rosser .([e-mail],
336.665.5620), or Richard 'Darling ([e-mail], 919:481:5740) with any questions
or comments-.
Sincerely,
PILI DMONT TRIAD AIRPORT AUTHORITY
KevinJ. Baker, P.E.
Executive Director
LJA/RBD/JAR/KJB,:rbd
Enclosure: Figure 1: Cross -Field Taxiway Alternatives
cc: Daren Capps, P.E. - NCDOT Transportation'.Program Management
Larry Allen, R.E.; Richard Darling - Michael Baker Engineering, Inc.