U-5863 scoping letter

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MICHAGL S. REGAN
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E.�nVirorimen(ul LINUA CULPEPPER
QUQ�!(Y lnlerini Direrinr
November 30, 2017
MEMORANDUM
'fo: tCrista H. Kimmel Design Lngineer, NCDOT Division 3
From: Joaime S[eenhuis, NC Division of Water Resources, Wilmingfon Offic���
Subject: Scopuig comments on proposed improvements [o Castle Hayne Road froin I-140/US 17 Bypass to SR
1310 (Division Drive) nmth of US 74 (MLK Drive) u� New Hanover County, S'I'lP U-5863.
Reference your correspondence dated November 15, 2017 u� which you requested conmien[s for the re(ere��ced
projecG Prelimin�ry nnalysis ofthe project reveals the potential for multiple impacts to streams and jurisdictio��al
wetlands in the project area. More specifically, impacts to:
Stream Name River Basia Stream Classification(s) Strcam hidex 303(d) Listing
Number
Ness Creek Cape Fear C;SW 18-74-62 N/A
Smith Creek Ca e Fear C;Sw 18-74-63 N/A
Further inves[igations at a higher resolution should be undertaken to verify Ihe presence of other streams and/or
jurisdictional wetlands in the area. In lhe event [hat anyjurisdic[ional areas are identified, the Division of Water
Resources requests that NCDOT consider the following environmental issues for the proposed project
General Project Comments:
'I'he environmen[al documen[ should provide a de[ailed and itemized presentation of the proposed 'unpacts to
wedands and streams wi[h corresponding mapping, If mitiga[ion is necessary as required by I SA NCAC
2H.0506(h), i[ is preferable to presen[ a conceptual (if not finalized) mi[iga[ion plan with [he environmental
documentation. Appropriate mi[igation-plans will be required prior to issuance of a 401 Water Quality
Certification.
2, Environmental impact statement alternatives shall consider design critcria that reduce the impac[s to streams
and wetlauds Rom storm water runoff. These altern�[ives shall include road designs Ihat allow for treatmen[
of Nie storm wnter runoff tlirough best manugement practices as detailed in [he most recent version of the
North Cm�oli»n Depnrhiien( ofTraiuspor�ntion Stornnva�ei� Bes[ Mnnngeme�vt Practices Too! box maimal,
such as grassed swales, buffer areas, prefonned scour holes, retention basins, etc.
3. After [he selection of the preferred alternative and prior to an issuance of[he 401 Water Quality Certi£ca[ion,
the NCDO'I' is respectfully reminded [hat tltey will need to demonstrate the avoidance and minimization of
impTc[s to wetlands (and sU'eams) to the maximunt extent practical. In accordznce wi[h Ihe �nvironmen[al
Managemen[ Commission's Rules (I SA NCAC 211.0506[h]), mitigation will be required for impacts of
greater than I acre to wetlands. In [he event [hat mitigation is required, the mitigation plan shall be designed
to replace appropriate los[ func[ions and values. North Carolina Divisioi� of' Mi[igation Services may be
available for assis[ance with wetland mi[iga[ion.
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State nl'North Carolinu i I'naironmenud Qu:dm
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4. In accordance with the Environmental Management Commission's Rules Q SA NCAC 2H.0506[h]),
mitigation will be requ'ved for impacts of greater than 150 linear feet to any perennial stream. ln the event
that mitigation is required, the mitigation plan shall be designed to replace appropriate lost functions and
values. The North Cazolina Division of Mitigation Services may be available for assistance with skeam
mitigation.
5. Future documentation, including the 401 Water Quality Certification Application, shall continue to include an
itemized listing of the proposed wetland and stream impacts with corresponding mapping.
6. The NCDWR is very concerned with sediment and erosion impacts that could result from this project. The
NCDOT shall address these concems by describing the potential impacts that may occur to the aquatic
environments and any mitigating factors that would reduce the impacts.
7. An analysis of cumulative and secondary impacts anticipated as a resWt of this project is required. The type
and detail of analysis shall conform to the NC Division of Water Resource Policy on the assessment of
secondary and cumulative impacts dated April 10, 2004.
8. The NCDOT is respectfully reminded that all impacts, including but not limited to, bridging, fill, excavation
and clearing, and rip rap to jurisdictional wetlands, streams, and riparian buffers need to be included in the
final impact calculations. These impacts, in addition ro any construction impacts, temporary or otherwise,
also need to be included as part oFthe 401 Water Quality Certi£cation Application.
9. Where streams must be crossed, the NCDWR prefers bridges be used in lieu of culverts. However, we realize
that economic considerations often require the use of culverts. Please be advised that culverts should be
countersunk ro allow unimpeded passage by fish and other aquatic organisms. Moreover, in areas where high
quality wetlands or streams are impacted, a bridge may prove preferable. When applicable, the NCDOT
should not install the bridge bents in the creek, to the ma�cimum extent practicable.
] 0. Whenever possible, the NCDWR prefers spanning structures. Spa�ming structures usually do not require
work within the stream or grubbing of the streambanks and do not require sheam channel realignment. The
horizontal and vertical clearances provided by bridges shall allow for human and wildlife passage beneath the
skvcture. Fish passage and navigation by canoeists and boaters shall not be blocked. Bridge supports (bents)
should not be placed in the stream when possible.
l 1. Bridge deck drains shall not discharge directly into the stream. Stormwater shall be direc[ed across the bridge
and pre-treated through site-appropriate means (grassed swales, pre-formed scour holes, vegetated buffers, etc.)
before entering the sheam. To meet the requirements of NCDOT's NPDES permit NC50000250, please refer
to the most recent version of the North Carolina Department ofTransportatron Stormwater Best Management
Practrces Toolbox manual For approved measures.
12. Sediment and erosion control measures should not be placed in wetlands or sheams.
13. Borrow/waste areas should avoid wetlands to the maximum extent practicaL Impacts to wetlands in
borrow/waste areas will need to be presented in the 401 Water Quality Certification and could precipitate
compensatory mitigation.
l4. The 401 Water Quality Certification application will need to specifically address the proposed methods for
stormwater management. More specifically, stormwater shall not be permitted to discharge d'vectly into
sheams or surface waters.
I5. Based on the information presented in the document, the magnitude of impacts ro weUands and sheams may
require an Individual Peanit (IP) or Nationwide (N W) application, depending on the amount of impacts
proposed, to the Corps of Engineers and corresponding 401 Water Quality Certification. Please be advised
that a 40l Water Quality Certification requires satisfactoty protection of water quality to ensure that water
quality standards are met and no wetland or stream uses are lost. Fi�al permit authorization will require the
submittal of a formal application by the NCDOT and written concurrence from the NCDWR. Please be

aware that any approval will be contingent on appropriate avoidance and minimization of wetland and sVeam
impacts to the maximum extent practical, the development of an acceptable s[ormwater management plan,
and the inclusion of appropriate mitigation plans where appropriate.
16. If concrete is used during conshuction, a dry work azea shall be maintained to prevent direct contact between
curing concrete and stream water. Water that inadvertently contacts uncured concrete shall not be dischazged
to surface waters due to the potential for elevated pH and possible aquatic life and fish kills.
l7. If temporary access roads or detours are constructed, the site shall be graded to its preconstruction contours
and elevations. Disturbed areas shall be seeded or mulched to stabilize the soil and appropriate native woody
species shall be planted. When using temporary sWctures the area shall be cleared but not grubbed. Clearing
the area with chain saws, mowers, bush-hogs, or other mechanized equipment and leaving the stumps and root
mat intact allows the area to re-vegetate naturally and minimizes soil disturbance.
18. Unless otherwise authorized, placement of culverts and other structures in waters and sheams shall be placed
below the elevation of the sheambed by one foot for all culverts with a diameter greater than 48 inches, and
20 percent of the culvert diameter for culverts having a diameter less [han 48 inches, to allow low flow
passage of water and aquatic life. Design and placement of culverts and other shuctures including temporary
erosion control measures shall not be conducted in a manner that may result in dis-equilibrium of wetlands or
streambeds or banks, adjacent to or upstream and downstream of the above structures. The applicant is
required to provide evidence that the equilibrium is being maintained if requested in writing by the NCDWR.
If this condition is unable to be met due to bedrock or other limiting features encountered during construction,
please contact the NCDWR for guidance on how to proceed and to determine whether or not a permit
modification will be required.
19. lf multiple pipes or barrels aze required, they shall be designed to mimic na[ural stream cross section as
closely as possible including pipes or barzels at flood plain elevation, floodplain benches, and/or sills may be
requ'ved where appropriate. Widening the stream channel should be avoided. Sheam channel widening at the
inlet or outlet end of shuctures typically decreases water velocity causing sediment deposition that requ'ves
increased maintenance and disrupts aquatic life passage.
20. If foundation test borings aze necessary; it shall be noted in the document. Geotechnical work is approved
under General 401 CertiFication Number 3883/Nationwide Permit No. 6 for Survey Activities.
21. Sediment and erosion control measures sufficient to protect water resources must be implemented and
maintained in accordance with the most recent version of North Carolina Sediment and Erosion Control
Planning and Design Manual and the most recent version of NCS000250.
22. All work in or adjacent to sheam waters shall be conducted in a dry work azea. Approved BMP measures
from the most current version of the NCDOT Construction and Maintenance Activities manual such as
sandbags, rock berms, cofferdams and other diversion structures shall be used to prevent excavation in
flowing water.
23. While the use of National Wetland Inventory (N WI) maps, NC Coastal Region Evaluation of Wetland
Significance (NGCREWS) maps and soil survey maps are useful tools, their inherent inaccuracies require
that qualified personnel perform onsite wetland delineations prior to permit approval.
24. Heavy equipment should be operated from the bank rather than in stream channets in order to minimize
sedimentation and reduce the likelihood of inuoducing other pollutants into streams. This equipment shall be
inspected daily and maintained to prevent contamination of surface waters from leaking fuels, lubricants,
hydraulic fluids, or other toxic materials.
25. Riprap shall not be placed in the active thalweg channel or placed in the streambed in a manner that precWdes
aquatic life passage. Bioengineering boulders or structures should be properly designed, sized and installed.

26. Riparian vegetation (native trees and shrubs) shall be preserved to the maximum extent possible. Ripazian
vegetation must be reestablished within the construction limits oFthe project by the end of the growing season
following completion of construction.
Thank you for requesting our input at this time. The NCDOT is reminded that issuance of a 401 Water Quality
Certi6cation requires that appropriate measures be instituted to enswe that water quality standards are met and
designated uses are not degraded or lost. If you have any questions or require additional information, please contact
me at [phone] or [e-mail].
Electronic copy anly distribution:
Brad Shaver, US Army Corps oFEngineers, Wilmington Field Otiice
Cathy Brittingham, NC Division of Coastal Management
Steven Lane, NC Division of Coastal Management
Kristi Lynn Carpenter, NCDWR
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