20130277_Scoping Comments_20111014

4
NCDENR
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Beverly Eaves Perdue Coleen H. Sullins
Governor Director
October 14, 2011
MEMORANDUM
TO: Pamela Williams, NCDOT Priority Project Office
FROM: Rob Ridings, NC Division of Water Quality, Transportation Permitting Unit fe
SUBJECT: Scoping Review of NCDOT's Proposed Design Build Bridge Replacement Projects in
Johnston County.
In reference to the Division 4 Design Build Bridge Replacement Projects' Onsite Reviews conducted
October 2011, the NCDWQ offers the following comments:
Proiect-Specific Comments
Bridge 80 on SR 1159 over Hannah Creek:
Hannah Creek is class C; NSW; 303(d) impaired waters of the State. NCDWQ is very concerned
with sediment and erosion impacts that could result from this project. NCDWQ recommends that
the most protective sediment and erosion control BMPs be implemented in accordance with Design
Standards in Sensitive Watersheds to reduce the risk of nutrient runoff to Hannah 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 Stormwater Best
Management Practices.
Bridge 327 on SR 2141 over Moccasin Creek
Bridge 43 on SR 1122 over Mill Creek
Bridge 129 on SR 1006 over Little Black Creek
Bridge 71 on NC 96 over Buffalo Creek
Bridge 240 on SR 2127 over Buffalo Creek
Bridge 241 on SR 2127 over Long Creek
Bridge 282 on SR 2130 over Buffalo Creek
Bridge 236 on SR 1934 over Little River
Bridge 72 on NC 210 over Swift Creek
Bridge 70 on US 301 over Neuse River
Bridge 56 on US 301 over Holts Lake:
These waters are class NSW, Nutrient Sensitive Waters of the State. NCDWQ is very concerned
with sediment and erosion 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 these streams. NCDWQ requests that road design plans provide treatment of the storm
wafer runoff through best management practices as detailed in the most recent version of
NCDWQ's Stormwater Best Management Practices.
Tianspon. 'ior Prmitting Unit
1650 Nail 9en ce Cc ter, Raleigh, Ne ;h C..=..alir?, 27699-1650
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Dee Freeman
Secretary
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General Comments Regarding Bridge Replacement Proiects
I. All of the reviewed projects are in the Neuse River Basin; except for Bridge 88 over Mingo Swamp
(which is in the Cape Fear Basin). Riparian buffer impacts shall be avoided and minimized to the
greatest extent possible pursuant to I SA NCAC 28.0233.
2. 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.
3. NCDWQ is very concerned with sediment and erosion impacts that could result from these projects.
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.
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 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. A II 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 re- luce the likelihooc' of introducing otbcr pollutants into Ftreams. 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. 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.
13. 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.
14. 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.
15. 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.
16. Sediment and erosion control measures should not be placed in wetlands or streams.
17. 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.
18. 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. 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 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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