20151022 Ver 1_Scoping Comments_20090824

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NCDENR
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Beverly Eaves Perdue Coleen H. Sullins
Governor Director
MEMORANDUM
TO: Natalie Lockhart, Bridge Project Planning Engineer, NCDOT PDEA
Dee Freeman
Secretary
August 24, 2009
FROM: Polly Lespinasse, NCDWQ, Mooresville Regional Office
SUBJECT: Scoping Review of NCDOT's Proposed Bridge Replacement Projects: 8-4981
(Gaston County), B-5150, (Catawba County), B-5110 and B-4405 (Alexander
County), B-5155 (Lincoln County), B-5142 and 8-4982 (Iredell County)
In reply to your correspondence dated August 13, 2009 (received electronically on August 13, 2009) in
which you requested comments for the above referenced projects, the North Carolina Division of Water
Quality (NCDWQ) offers the following comments:
Project-Specific Comments
B-5142, Bridge No. 57 Over Cornelius Creek, Iredell County
Review of the project reveals the presence of surface waters classified as Water Supply Critical
Area in the project study area. Given the potential for impacts to these resources during the project
implementation, the NCDWQ requests that NCDOT strictly adhere to North Carolina regulations
entitled "Design Standards in Sensitive Watersheds" (15A NCAC 04B .0124) throughout design and
construction of the project. This would apply for any area that drains to streams having WS CA
(Water Supply Critical Area) classifications.
Should the bridge project be located within the Critical Area of a Water Supply NCDOT may be
required to design, construct, and maintain hazardous spill catch basins in the project area. The
number of catch basins installed shall be determined by the design of the bridge, so that runoff
would enter said basin(s) rather than flowing directly into the stream, and in consultation with the
DWQ.
2. This project is within the Catawba River Basin. Riparian buffer impacts shall be avoided and
minimized to the greatest extent possible pursuant to 15A NCAC 26.0243.
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
Transportation Permitting Unit
1650 Mail Service Center, Raleigh, North Carolina 27699-1650
Location: 2321 Crabtree Blvd., Raleigh, North Carolina 27604
Phone: [phone] FAX: [phone]
Internet: hltp:llh2o.enrstate.nc.us/nmetlands/
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NorthCarolinat
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An Equal Opportunity 1 Affirmative Action Employer
1. 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.
2. 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.
3. 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).
4. 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.
5. 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.
6. 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.
7. 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.
8. 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. ,
9. 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.
10. 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.
11. 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.
12. 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.
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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 the Bridge with a Culvert
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 NCDWQ. If this condition is unable to be met due to bedrock
or other limiting features encountered during construction, please contact the NCDWQ for guidance
on how to proceed and to determine whether or not a permit modification will be required.
2. 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.
3. 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 [phone].
cc: Steve Lund, US Army Corps of Engineers, Asheville Field Office (electronic copy)
Ron Lucas, Federal Highway Administration
Chris Militscher, Environmental Protection Agency (electronic copy)
Marla Chambers, NC Wildlife Resources Commission (electronic copy)
Marella Buncick, US Fish and Wildlife Service (electronic copy)
Sonia Gregory, NCDWQ Central Office (electronic copy)
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