20090822 Ver 1_Scoping Comments_20070702

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Michael F. Easley, Governor
William G. Ross Jr., Secretary
North Carolina Department of Environment and Natural Resources
Coleen H. Sullins, Director
Division of Water Quality
July 2, 2007
MEMORANDUM
TO: Hank Schwab, Bridge Project Planning Engineer, NCDOT
FROM: Polly Lespinasse, NC Division of Water Quality, Mooresville Regional Office
SUBJECT: Scoping Review of NCDOT's Proposed Bridge Replacement Projects: B- 4517 and B-
4519, Gaston County
In reply to your correspondence dated June 6, 2007 (received June 12, 2007) in which you requested
comments for the above referenced projects, the NC Division of Water Quality (DWQ) offers the following
comments:
Project Specific Comments
B-4517, Bridge No. 49 Over Crowders Creek, Gaston County
Crowders Creek is a Class C; 303(d) waters of the State. Crowders Creek is on the 303(d) list for impaired use
for aquatic life due to impaired biological integrity. DWQ is very concerned with sediment and erosion impacts
that could result from this project. DWQ recommends that the most protective sediment and erosion control
BMPs be implemented to reduce the risk of nutrient runoff to Crowders Creek. DWQ requests that road design
plans provide treatment of the storm water runoff through best management practices as detailed in the most
recent version of NC DWQ Stormwater Best Management Practices.
B-4519, Bridge 155 Over Little Long Creek, Gaston County
Little Long Creek is Class C; 303(d) Waters of the State. Little Long Creek is on the 303(d) list for impaired
use for aquatic life due to urban runoff (historical listing). DWQ is very concerned with sediment and erosion
impacts that could result from this project. DWQ recommends that the most protective sediment and erosion
control BMPs be implemented to reduce the risk of nutrient runoff to Little Long Creek. DWQ requests that
road design plans provide treatment of the storm water runoff through best management practices as detailed
in the most recent version of NC DWQ Storm Water Best Management Practices.
General Comments Regarding Bridge Replacement Projects
DWQ is very concerned with sediment and erosion impacts that could result from this project. North
Carolina Department of Transportation (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 3494/Nationwide Permit No. 6 for Survey Activities.
NorehCarolina
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North Carolina Division of Water Quality 610 East Center Avenue, Suite 301
Internet: h2o.enr.state.nc.us Mooresville, NC 28115
Phone[phone]
Fax [phone]
An Equal Opportunity/Affirmative Action Employer- 50% Recycled/10% Post Consumer Paper
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Mr,, Hank Schwab
Page Two
3. 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).
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, the DWQ prefers spanning structures. Spanning structures usually do not require
work within the stream or grubbing of the stream banks 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.
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 NC DWQ
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. Bridge supports (bents) shall not be placed in the stream when possible.
9. 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.
10. 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.
11. 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
shall be used to prevent excavation in flowing water.
12. 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.
13. 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 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.
MrN Hank Schwab
Page Three
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 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.
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 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.
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. 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 Polly Lespinasse at [phone].
cc: Steve Lund, US Army Corps of Engineers, Asheville Field Office
Ron Lucas, Federal Highway Administration
Chris Militscher, Environmental Protection Agency
Marla Chambers, NC Wildlife Resources Commission
Marella Buncick, US Fish and Wildlife Service
Sonia Gregory, DWQ Central Regional Office
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