20151018 Ver 1_Scoping Comments_20090917

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NC® NR
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Beverly Eaves Perdue Colleen H. Sullins Dee Freeman
Governor Director Secretary
September 17, 2009
MEMORANDUM
TO: Christy Wright Huff, NCDOT Bridge Project Planning Engineer
FROM: Polly Lespinasse, NCDWQ, Mooresville Regional Office
SUBJECT: Scoping Review of NCDOT's Proposed Bridge Replacement Projects: B- 4730 (Chatham County),
B-4967 (Scotland/Hoke County Line), and B-5164 (Moore County)
In reply to your correspondence dated August 17, 2009 (received August 21, 2009) in which you requested comments for
the above referenced projects, the NCDWQ offers the following comments:
Project Specific Comments:
B-4730, Bridge No. 108 Over Terrells Creek, Chatham County
1. Terrells Creek is a Class WS-IV, NSW Waters of the State. NCDWQ is very concerned with sediment and
erasion impacts that could result from this project. NCDWQ recommends that highly protective sediment and
erosion control BMPs be implemented to reduce the risk of nutrient runoff to Terrells Creek. NCDWQ requests
that road design plans provide treatment of the storm water runoff through best management practices as detailed
in the most recent version of NCDWQ's Stormwater Best Management Practices.
B-4967, Bridge No. 8 Over Drowning Creek, Scotland/Hoke County Line
2. Review of the project reveals the presence of surface waters classified as C, Sw, HQW, High Quality Waters of
the State in the project study area. This is one of the highest classifications for water quality. Pursuant to 15A
NCAC 2H .1006 and 15A NCAC 213 .0224, NCDOT will be required to obtain a State Stormwater Permit prior to
construction except in North Carolina's twenty coastal counties.
3. Any anticipated bank stabilization associated with culvert installations or extensions 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 bank stabilization necessary due to culvert
installation.
4. Any anticipated dewatering or access structures necessary for construction of bridges should be addressed in the
CE. 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.
General Comments Regarding Bridge Replacement Projects
5. NCDWQ is very concerned with sediment and erosion impacts that could result from this project. 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.
Mooresville Regional Office
Location: 610 East Center Ave., Suite 301 Mooresville, NC 28115
Phone: [phone] Fax: [phone] \ Customer Service: 1-877-623-6748
Internet: vnvvv.nmaterquality.org
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6. If foundation test borings are necessary ; it shall be noted in the document. Geotechnical work is approved under
General 401 Certification Number 3687/Nationwide Permit No. 6 for Survey Activities.
7. If a bridge is being replaced with a hydraulic conveyance other than another bridge, NCDWQ 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. Whenever possible, NCDWQ 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.
10. 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 NCDWQ's Stormwater Best Management
Practices.
11. 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.
12. 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.
13. 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.
14. All work in or adjacent to stream waters shall be conducted in a dry work area unless otherwise approved by
NCDWQ. 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 shall be used to
prevent excavation in flowing water.
15. 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. This equipment shall be
inspected daily and maintained to prevent contamination of surface waters from leaking fuels, lubricants, hydraulic
fluids, or other toxic materials.
16. In most cases, the NCDWQ prefers the replacement of the existing structure at the same location with road
closure. If road closure is not feasible, a temporary detour shall 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 shall 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.
General Comments if Replacing a Bridge with a Culvert
17. 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-equilibrium 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 the NCDWQ. If this condition is unable to be met due to
bedrock or other limiting features encountered during construction, pleasa contact the NCDWQ for guidance on
how to proceed and to determine whether or not a permit modification will be required.
18. 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 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.
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19. 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 shall be properly designed, sized and installed.
Thank you for requesting our input at this time. 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 Polly Lespinasse at (704)
663-1699.
cc: Kimberly Garvey, US Army Corps of Engineers, Wilmington Field Office (electronic copy)
Felix Davila, Federal Highway Administration
Chris Militscher, Environmental Protection Agency (electronic copy)
Travis Wilson, NC Wildlife Resources Commission (electronic copy)
Gary Jordan, US Fish and Wildlife Service (electronic copy) .
Ken Averitte, NCDWQ Fayetteville Regional Office (electronic copy)
Sonia Gregory, NCDWQ Central Office (electronic copy)
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