20151065 Ver 1_RAI_response_20151215

PIEDMONT TRIAD AIRPORT AUTHORITY
December 14, 2015
NC Department of Environmental Quality
Division of Water Resources
401 & Buffer Permitting Unit
512 N. Salisbury St., 90' Floor
Raleigh, NC 27604
Attention: Ms. Sue Homewood
Subject: Application for Section 404 Individual Permit, Section 401 Water Quality
Certification, and Jordan Buffer Allowance for Northvest Taxiway Connector
at Piedmont Triad International Airport
The Piedmont Triad Airport Authority (PTAA) has received your Request for Additional
Information dated November 16, 2015 and offer the following responses to your comments:
1. A Public Notice issued by the U.S. Army Corps of Engineers (U,SACE) will be necessary to begin the
proper consideration of an application (pursuant to 15A NCAC 02H.0503)
The USAGE Public Notice was issued November 19, 2015 and is available at
httn://www.saw.usace.armv.mil/Missions/ReaulatorvPermitPro aramlPublieNotices/tabid/
10057/Article/63 0474/saw-2012-01547. aspx.
2. Please clam whether the Division of Energy, Mineral and Land Resources will require riprap at the outlet
of the stream culvert as part of the Erosion &.Sedimentation Control Plan approval. If riprap is required,
please enumerate and clearly label the temporary and permanent impacts on the site plan and submit a
channel restoration detail. Riprap must be located below the stream bed elevation. [15ANCAC 02H
.050669 and (g)]
Riprap has been added at the outlet of the stream culvert to provide energy dissipation..
The impacts have been added to the revised plan and tables (enclosed). A channel detail
has been added indicating that the Riprap must be embedded below stream bed elevation.
3. All work must be done "in the dry". Therefore, dewatering methods will be necessary to temporarily
dewater the stream channel during culvert installation. Please provide a construction sequence that details
the method of dewatering to be utilized at the site and the sequence of construction events to be followed to
ensure compliance -with this condition. In addition, please ensure that the location of the temporary impacts
are shown on the construction drawings and clearly indicated in application. [15A NCAC 02H
.0502(b)(3)]
A construction sequence has been added to the drawings for the stream crossing
indicating the method of dewatering to be utilized. Temporary impacts are also noted.
4. The Jordan Lake Buffer Rules state that Temporary Sediment and Erosion Control Devices in Zone 1 are
allowableprovided that "there are no practical alternatives" and that "sediment' and erosion control for
upland areas is addressed to the maximum extentpractical outside the buffer". Please provide a more
detailed justification and/or analysis regarding this impact. [15A NCAC 02B.0237(9) and 15A NCAC 02B
10OOA Ted Johnson Parkway • Greensboro, North Carolina 27409 . Phone; 306,665.5600 9 Fax; 336.665,1425 MM

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The erosion and sediuLelit coiL�trol design for this =ea has been modified to significantly
reduce the impact to Zone 1. The remaininr, impact is small and unavoidable to allow for
adequato orosion control during culvrrt consiruedon. tJvery offort was madr, io movr, the
temporary erosion conLrol measure outside the buffer to treat the majority of the upland
areas. However_ due to the steep slopes and grading requirements in the immediate area
of the culvert construction, a small portion of temporary storage excavation must be
located at the edre of Zone 1.
J. i he sordan sake Duffer rules state Maar a empora y ,Sedimem and Erosion Control Devices in 4one 1 are
allowable provided char "rhe disturbed area is restored to pre-consrruction topographic and hydrologic
condirions immediarely after consrrucrion is complere and replanred wirh comparable vegetarian ". rlease
provide a buffer resrorarion plan for these areas. [I 5A NCA% 02B. 02-) (9)]
x buffor restoration Plan has been added to the drawings.
6. Ir appears rhar a small werland berween ponds E-3 and E-4 has been avoided however rhe narure of rhe
impacrs surrounding it may- cause secondary impacts to rhis werland. Please provide jurrher analysis and
any measures rhar PTAA will rake ro ensure rhe werland continues ro juncrion properly. [15A NCAC 02H
.0502(g)]
The sire plan has been modified with Lhe inLenL of providing proposed hydrologic
conditions to allow for the small wetland to maintain its present function and avoid
secondary impacts. A BMP is proposed upstream that will filter runoff and can be
designed to provide release that will mul,ic the existinr, hydrologic condition.
r -lease provide a conceptual stormwarer management plan for rhe future phases of rhe project rhar includes
thefollowing fIja 1v7A7azrr .a -)06(b)()) and (c)(d)]:
a. A depiction of the drainage areas on the sire.
b. b. An esrimare of the percenr imperviousness associared with each of the drainage areas.
c. A calcularion of rhe water quality volume associated wirh each drainage area.
d. A depiction of a BWs proposed for the sire. For each BMP, note rhe size and type on rhe plan
sheer.
ConorYtual stormwater manago.uOni Flan snoois navr, been added io ihr, rrmit drawings
and provide the information requested above.

Ms. Sale HomaewoodMs. Sue Holmewood
December 14, .2015
Paxe 3 of 3
We appreciate your continued consideration of this application for Section 401 Water quality
Certification. Please feel flee to contact me (rosser soai, .o=g, 336.665.5620) or
Richard Darling ([e-mail], 919.481.5740) with additional quesLions or
comments. One (1) comYlete set of revised permit drawings are being provided to USACE with
three t3) comriete copies to NCDEQ.
Sincerel.,,
PIEDMONT TRIAD AIRPORT AU i rnr)m i x
�"t10
J. A ex Rosser, P.E.
Deputy Executive Director
�5iVRti/AR:rd
Enclosures: Revised Pluus (15 sheets, full-size and I1"--17")
cc: Karen Higgins_ NCDEQ
David Bailey; USACE
Richard Darling, Scott Brookhart; tvrichael Baker InLernadonal