20121131_Scoping Comments_20090108

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Michael F. Easley, Governor
William G. Ross Jr., Secretary
North Carolina Department of Environment and Natural Resources
Coleen Sullins, Director
Division of Water Quality
January 8, 2009
NIENIORANDITI\I
To: Natalie Lockhart, NC Department of Transportation, Bridge Project Planning Engineer Project
Design and Development Branch
From: Amy Euliss, NC Division of Water Quality, Winston-Salem Regional Office
Subject: Scoping comments on Bridge Replacement Project for Bridge No. 29 and 30 over the Little
Yadkin River in Stokes County, TIP B-4645.
Reference your correspondence dated December 22, 2008 in which you requested comments for the
referenced project. The Preliminary analysis of the project reveals the potential for multiple impacts to
perennial streams and jurisdictional wetlands in the project area. More specifically, impacts to:
Stream Name River Basin Stream
Classifications Stream Index
Number
Little Yadkin River Yadkin WS-IV 12-77
Further investigations at a higher resolution should be undertaken to verify the presence of other streams
and/or jurisdictional wetlands in the area. In the event that any jurisdictional areas are identified, the
Division of Water Quality requests that NCDOT consider the following environmental issues for the
proposed project:
General Project Comments:
1. The environmental document shall provide a detailed and itemized presentation of the proposed
impacts to wetlands and streams with corresponding mapping. if mitigation is necessary as
required by 15A NCAC 2H.0506(h), it is preferable to present a conceptual (if not finalized)
mitigation plan with the environmental documentation. Appropriate mitigation plans will be
required prior to issuance of a 401 Water Quality Certification.
2. Environmental assessment alternatives shall consider design criteria that reduce the impacts to
streams and wetlands from storm water runoff. These alternatives shall include road designs that
allow for treatment of the storm water runoff through best management practices as detailed in
the most recent version of NC DWQ Stormwater Best Management Practices, such as grassed
swales, buffer areas, preformed scour holes, retention basins, etc.
Any anticipated dewatering or access structures necessary for construction of bridges
and/or culverts should be addressed in the Categorical Exclusion (CE) document. It is
understood that final designs are not determined at the time the CE is developed.
However, the CE should discuss the potential for dewatering and access measures
necessary due to bridge construction.
Transportation Permitting Unit
1650 Mail Service Center, Raleigh, North Carolina 27699-1650
2321 Crabtree Boulevard, Suite 250, Raleigh, North Carolina 27604
Phone: [phone] / FAX [phone] / Internet: http://h2o.enr,state.nc.us/ncwetfands
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4 After the selection of the preferred alternative and prior to an issuance of the 401 Water Quality
Certification, the NCDOT is respectfully reminded that they will need to demonstrate the
avoidance and minimization of impacts to wetlands (and streams) to the maximum extent
practical In accordance with the Environmental Management Commission's Rules { 15A NCAC
2H 0506(h)), mitigation will be required for impacts of greater than 1 acre to wetlands In the
event that mitigation is required, the mitigation plan shall be designed to replace appropriate lost
functions and values The NC Ecosystem Enhancement Program may be available for use as
wetland mitigation
5 In accordance with the Environmental Management Commission's Rules { 15A NCAC
2H 0506(h)}, mitigation will be required for impacts of greater than 150 linear feet to any single
perennial stream In the event that mitigation is required, the rmtigation plan shall be designed to
replace appropriate lost functions and values The NC Ecosystem Enhancement Program may be
available for use as stream mitigation
6 DWQ is very concerned with sediment and erosion impacts that could result from this project
NC DOT shall address these concerns by describing the potential impacts that may occur to the
aquatic environments and any mitigating factors that would reduce the impacts
7 If a bridge is being replaced with a hydraulic conveyance other than another bridge, DWQ
believes the use of a Nationwide Permit may be required Please contact the US Army Corp of
Engineers to determine the required permit(s)
8 If the old bridge is removed, no discharge of bridge material into surface waters is allowed unless
otherwise authorized by the US ACOE Strict adherence to the Corps of Engineers guidelines for
bridge demolition will be a condition of the 401 Water Quality Certification
9 Bridge supports (bents) shall not be placed in the stream when possible
10 Whenever possible, the DWQ prefers spanning structures Spanning structures usually do not
require work within the stream or grubbing of the streambanks and do not require stream channel
realignment The horizontal and vertical clearances provided by bridges allow for human and
wildlife passage beneath the structure, do not block fish passage and do not block navigation by
canoeists and boaters
11 Bridge deck drains shall not discharge directly into the stream Stormwater shall be directed
across the bridge and pre-treated through site-appropriate means (grassed swales, pre-formed
scour holes, vegetated buffers, etc ) before entering the stream Please refer to the most current
version of NC DWQ Stormwater Best Management Practices
12 If concrete is used during construction, a dry work area shall be maintained to prevent direct
contact between curing concrete and stream water Water that inadvertently contacts uncured
concrete shall not be discharged to surface waters due to the potential for elevated pH and
possible aquatic life and fish kills
13 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 should be planted When using temporary structures 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
14 Placement of culverts and other structures in waters, streams, and wetlands shall be below the
elevation of the streambed 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 than 48 inches, to allow low
flow passage of water and aquatic life Design and placement of culverts and other structures
including temporary erosion control measures shall not be conducted in a manner that may result
in dis-equilibnum of wetlands or streambeds or banks, adjacent to or upstream and down stream
of the above structures The applicant is required to provide evidence that the equilibrium is being
maintained if requested in writing by DWQ If this condition is unable to be met due to bedrock
or other limiting features encountered during construction, please contact the NC DWQ for
guidance on how to proceed and to determine whether or not a permit modification will be
required
15 If multiple pipes or barrels are required, they shall be designed to mimic natural stream cross
section as closely as possible including pipes or barrels at flood plain elevation and/or sills where
appropriate Widening the stream channel shall be avoided Stream channel widening at the inlet
or outlet end of structures typically decreases water velocity causing sediment deposition that
requires increased maintenance and disrupts aquatic life passage '
16 If foundation test borings are necessary, it should be noted in the document Geotechmcal work
is approved under General 401 Certification Number 3494/Nationwide Permit No 6 for Survey
Activities
17 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
18 All work in or adjacent to stream waters shall be conducted in a dry work area unless otherwise
approved by NC DWQ Approved BMP measures from the most current version of NCDOT
Construction and Maintenance Activities manual such as sandbags, rock berms, cofferdams and
other diversion structures should be used to prevent excavation in flowing water
19 Sediment and erosion control measures shall not be placed in wetlands and streams
20 Borrow/waste areas shall avoid wetlands to the maximum extent practical Impacts to wetlands
in borrow/waste areas could precipitate compensatory mitigation
21 While the use of National Wetland Inventory (NWI) maps, NC Coastal Region Evaluation of
Wetland Significance (NC-CREWS) maps and soil survey maps are useful tools, their inherent
inaccuracies require that qualified personnel perform onsite wetland delineations prior to permit
approval
22 Heavy equipment shall be operated from the bank rather than in stream channels in order to
minimize sedimentation and reduce the likelihood of introducing other pollutants into streams
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This equipment shall be inspected daily and maintained to prevent contammation of surface
waters from leaking fuels, lubricants, hydraulic fluids, or other toxic materials
23 In most cases, the DWQ prefers the replacement of the existing structure at the same location
with road closure If road closure is not feasible, a temporary detour should be designed and
located to avoid wetland impacts, minimize the need for clearing and to avoid destabilizing
stream banks If the structure will be on a new alignment, the old structure shall be removed and
the approach fills removed from the 100-year floodplain Approach fills should be removed and
restored to the natural ground elevation The area shall be stabilized with grass and planted with
native tree species Tall fescue shall not be used in riparian areas
24 Riprap shall not be placed in the active thalweg channel or placed in the streambed in a manner
that precludes aquatic life passage Bioengmeenng boulders or structures should be properly
designed, sized and installed
Thank you for requesting our input at this time The DOT is reminded that issuance of a 401 Water
Quality Certification requires that appropriate measures be instituted to ensure 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 Amy Euliss at am y uliss(&ncmail net or [phone]
cc John Thomas, US Army Corps of Engineers, Raleigh Field Office
Marla Chambers, NC Wildlife Resources Commission, e-copy
DWQ Wetlands/401 Transportation Unit
File Copy