HomeMy WebLinkAbout20170374 Ver 1_Scoping Comments_20130312I
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MCDENR
North Carolina Department of Environment and Natura
Division of Water Quality
Pat McCrory Charles Wakild, P. E
Governor Director
MEMORANDUM
TO: Tracy Walter, NCDOT Bridge Project Planning Engineer
FROM: Rob Ridings, NC Division of Water Quality, Transportation Permitting Unit
Resources
John E Skvarla, III
Secretary
March 12, 2013
SUBJECT: Scoping Review of NCDOT's Proposed Bridge Replacement Projects: B- 4770 (Johnston County),
B -4771 (Johnston County) and B -4838 (Wayne County).
In reply to your correspondence in which you requested comments for the above referenced projects, the NC Division of
Water Quality offers the following comments:
Project - Specific Comments
B -4770, Bridge No. 32 Over Hannah Creek, Johnston County
Hannah Creek is class C; NSW; 303(d) impaired'waters of the State. 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 Hannah 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 -4771, Bridge No. 11 Over Mill Creek, Johnston County
Mill Creek is class; NSW waters of the State. DWQ is very concerned with sediment and erosion impacts that
could result from this project. DWQ recommends that highly protective sediment and erosion control BMPs be
implemented to reduce the risk of nutrient runoff to Mill 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 -4838, Bridge No. 20 Over railroad [Nearest waterbody: Little River], Wayne County
The Little River is class C;NSW waters of the State. DWQ is very concerned with sediment and erosion impacts
that could result from this project. DWQ recommends that highly protective sediment and erosion control BMPs be
implemented to reduce the risk of nutrient runoff to any nearby streams or tributaries. 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.
Transportation and Permitting Unit
1650 Mail Service Center, Raleigh, North Carolina 27699 -1617
Location 512 N Salisbury St Raleigh, North Carolina 27604
Phone 919 - 807 -63001 FAX 919 - 807 -64921 Customer Service 1- 877 - 623 -6748
Internet wum.nmaterguality.org
An Equal Opportunity 1 Affirmative Action Employer
NorthCarolina
Naturall'y
All three projects: These projects are within the Neuse River Basin. Riparian buffer impacts shall be avoided and
minimized to the greatest extent possible pursuant to 15A NCAC 2B .0233.
General Comments Regarding Bridge Replacement Projects
1. 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.
2. If foundation test borings are necessary; it shall be noted in the document. Geotechnical work is approved under
General 401 Certification Number 3883/Nationwide Permit No. 6 for Survey Activities.
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.
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.
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.
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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.
14. 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.
15. 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 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.
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.
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 Rob Ridings at 919 -807-
6403.
cc: Tom Steffens, US Army Corps of Engineers, Washington Field Office
Chad Coggins, Division 4 Environmental Officer
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