HomeMy WebLinkAbout20191723 Ver 1_Bridge 75_B-4977_DWR Comments_20190816ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
LINDA CULPEPPER
Director
NORTH CAROLINA
Environmental Quality
August 16, 2019
MEMORANDUM
To: Jimmy Terry, Project Manager TGS Engineering on behalf of NCDOT Oterry@tgsengineers.com)
DocuSig//nlIed by: --II
From: Dave Wanucha, NC Division of Water Resources, Winston Salem Regional Offic �AVt, (6AA"A
89736FD146FE4AD...
Subject: Scoping comments on proposed Bridge No. 75 replacement in Wilkes County; STIP Project B-4977
Reference your correspondence dated August 1, 2019 for the above referenced project. Preliminary analysis of the
project reveals the potential for multiple impacts to streams and jurisdictional wetlands within the Yadkin River
Basin. More specifically, impacts to:
Bridge
Stream Index
303(d)
Stream
Stream Classification(s)
Number
Number
Listing
75
Fish Dam Creek
Water Supply WS -IV
12-35
No
Further investigations at a higher resolution should be undertaken to verify the presence of other streams and/or
jurisdictional wetlands in the area. If any jurisdictional areas are identified, the Division of Water Resources
requests that the applicant consider the following environmental issues for the proposed project:
Project Specific Comments:
General Project Comments:
The environmental document should 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
21-1.0506(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 impact statement 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 BMPs as detailed in the most recent version of the North Carolina
Department of Transportation Stormwater Best Management Practices Tool box manual, such as grassed
swales, buffer areas, preformed scour holes, retention basins, etc.
3. In accordance with the Environmental Management Commission's Rules (15A NCAC 2H.0506[h]),
mitigation will be required for impacts of greater than 300 linear feet to any perennial stream. If mitigation is
required, the mitigation plan shall be designed to replace appropriate lost functions and values. The North
Carolina Division of Mitigation Services may be available for assistance with stream mitigation.
D E Q�North Carolina Department of Environmental Quality I Division of Water Resources
512 North Salisbury Street 1 1617 Mail Service Center I Raleigh, North Carolina 27699-1617
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4. 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.
5. The NCDWR is very concerned with sediment and erosion impacts that could result from this project. The
NCDOT 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.
6. 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 to any construction impacts, temporary or otherwise,
also need to be included as part of the 401 Water Quality Certification Application.
7. 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 to 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 maximum extent practicable.
8. Whenever possible, the NCDWR 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 shall allow for human and wildlife passage beneath the
structure. Fish passage and navigation by canoeists and boaters shall not be blocked. Bridge supports (bents)
should not be placed in the stream when possible.
9. 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. To meet the requirements of NCDOT's NPDES permit NCS000250 please refer to
the most recent version of the North Carolina Department of Transportation Stormwater Best Management
Practices Toolbox manual for approved measures.
10. Sediment and erosion control measures should not be placed in wetlands or streams.
11. 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.
12. 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 directly into
streams or surface waters. To meet the requirements of NCDOT's NPDES permit NCS000250, please refer
to the most recent version of the North Carolina Department of Transportation Stormwater Best Management
Practices Toolbox manual for approved measures.
13. Based on the information presented in the document, the magnitude of impacts to wetlands and streams may
require an application to the Corps of Engineers and corresponding 401 Water Quality Certification. Please
be advised that a 401 Water Quality Certification requires satisfactory protection of water quality to ensure
that water quality standards are met, and no wetland or stream uses are lost. Final 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 stream impacts to the maximum extent practical, the development of an acceptable stormwater
management plan, and the inclusion of appropriate mitigation plans where appropriate.
14. 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. Concrete shall
be handled in accordance with the NPDES Construction Activities General Permit NCGO10000.
15. 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 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.
16. Unless otherwise authorized, placement of culverts and other structures in waters and streams shall be placed
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-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.
17. 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, floodplain benches, and/or sills may be
required where appropriate. Widening the stream channel should 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.
18. If foundation test borings are necessary; it shall be noted in the document. Geotechnical work is approved
under General 401 Certification Number 4085/Nationwide Permit No. 6 for Survey Activities.
19. 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.
20. All work in or adjacent to stream waters shall be conducted in a dry work area. 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.
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 should 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. This equipment shall be
inspected daily and maintained to prevent contamination of surface waters from leaking fuels, lubricants,
hydraulic fluids, or other toxic materials.
23. Riprap shall not be placed in the active thalweg channel or placed in the streambed in a manner that precludes
aquatic life passage. Bioengineering boulders or structures should be properly designed, sized and installed.
24. Riparian vegetation (native trees and shrubs) shall be preserved to the maximum extent possible. Riparian
vegetation must be reestablished within the construction limits of the 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
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
Dave Wanucha at (336) 776-9703 or dave.wanucha@ncdenr.gov.
Electronic copy only distribution:
Loretta Beckwith, US Army Corps of Engineers, Asheville Field Office
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