HomeMy WebLinkAbout20190591 Ver 1_B-5980-scoping_20171228;::,�
ROY COOPER
Go,�crnur
MICHAEL S. REGAN
Secr� rrn � �
Environmental LINDA CULPEPPER
QUClllty Lnterim Drre�vor
December 28, 2017
MEMORANDUM
To
From:
Christy Shumate, Project Mai7ager, AECOM
Rob Ridings, NC Divisiou of Water Resources, Transportation Permitting Branch
Subject Sco�ing comments on proposed improvements to I-95 and NC 4 Interchange in Nash County,
TIP No. B-5980, State Clcaringhouse Project No. 18-0157
Refcrence your correspondence received December 6, 2017 in which you requested co�nments for the referenced
project. Preliminary analysis of the projc,ct reveals the potential for multiple impacts to streams, buffers and/or
jurisdictional wetlands in tl�e project area. More specifically, impacts to:
Stream Name �ver Basin & Stream Classifications Stream Index 303(d) Listing?
Subbasin Number
Swift Creek TAR 02 C; NSW 2R-78-(2.5) No
Giles Branch TAR 02 C; NSW 28-78-4 No
Further investigations at a higher resolution should be undertaken to verify tl�e presence of other streams and/or
jurisdictional wetlands in the area. In the event that any jurisdictional areas are identi6ed, the Division of Water
Resources requests that NCDOT consider the following environmental issues for the proposed project:
Project Specific Comments:
Swift Creelc, Giles Branch, and their tributaries are class C; NSW waters of the State. The NCDWR is very
concerned with sediment and erosion unpacts that could result from tliis project The NCDWR reco�ninends
that highly protective sediment and erosion conh-ol BMPs be implemented to reduce the risk of nutrient nlnoff
to these sh-eams. Additionally, to meet the requirements of NCDOT's NPDES pennit NCS0000250, the
NCDWR rec�uests that road design plans provide treatment of the storm water ninoff through best management
practices as detailed in the most recent version of the Nor�tlr Car•olina Depar�tnzent of'Transportczdior� Stormu�ater
BesC Mcznage�nent Practices Toolbox manual.
This project is within the Tar-Pan�lico Basin. Riparian Uuffer iinpacts sl�all Ue avoided and miniinized to the
greatest extent possible pursuant to 15A NCAC 2B.0259. New development activities located ul the protected
50-foot wide riparian areas within the basul shall be liinited to "uses" identified within and constructed in
accordance with 15A NCAC .02B .0295. Buffer nutigation may be required for buffer impacts resulting froili
activities classified as "allowablz with mitigation" within the "Table of Uses" section of the B�iffer Rules or
require a variance under the Buffer Rules. A buffer i��iti�ation plan, including use of the North Carolina
Division of Mitigatioi� Services, must be provided to the NCDWR prior to approval of the Water Quality
Certification. Buffer mitigation may be required for buffer impacts resulting from activities classified as
"allowaUle with mitigation" within the "Table of Uses" section of the Buffer Rules or require a variance under
the Buffer Rules. A buffer mitigation plan, coordinated with the North Carolina Division of Mitigation
Services, must be provided to the NCDWR prior to approval of the Water Qliality Certification.
=�`Nnfihir�g Cnr���aares --
State of Noitli Carolina I Enviromnental Qutlity
1617 Mail Service Center I Raleigh, North Carolina 27699-1617
General Project Comments:
The environmental document should provide a detailed and itemized presentation of the proposed impacts to
wetlands and streams with corresponding mapping. If mitigation is necessary as required by 15A NCAC
2H.0506(h), it is preferable to present a conceptual (if not finalized) mitigation plan with the environmental
documentation. Appropriate mitigation plans will be required prior to issuance of a 401 Water Quality
Certification.
2. Environmental impact statement alternatives sha11 consider design criteria that reduce the impacts to streams
and wetlands from storm water runoff. These alternatives sha11 include road designs that a11ow for treatment
of the storm water runoff through best management practices as detailed in the most recent version of the
North Carolina Department of Transportation Stormwater Best Management Practices Tool box manual,
such as grassed swales, buffer areas, preformed scour holes, retention basins, etc.
After the selection of the preferred alternative and prior to an issuance of the 401 Water Quality Certification,
the NCDOT is respectfully reminded that they will need to demonstrate the avoidance and minimization of
impacts to wetlands (and streams) to the maximum extent practicaL In accordance with the Environmental
Management Commission's Rules (15A NCAC 2H.0506[h]), mitigation will be required for impacts of
greater than 1 aare to wetlands. In the event that mitigation is required, the mitigation plan shall be designed
to replace appropriate lost functions and values. North Carolina Division of Mitigation Services may be
available for assistance with wetland mitigation.
4. In accordance with the Environmental Management Commission's Rules (15A NCAC 2H.0506[h]),
mitigation will be required for impacts of greater than 300 linear feet to any perennial stream. In the event
that mitigation is required, the mitigation plan shall be designed to replace appropriate lost functions and
values. The North Carolina Division of Mitigation Services may be available for assistance with stream
mitigation.
5. Future documentation, including the 401 Water Quality Certification Application, shall continue to include an
itemized listing of the proposed wetland and stream impacts with corresponding mapping.
6. The NCDWR is very concerned with sediment and erosion impacts that could result from this project. The
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.
7. An analysis of cumulative and secondary impacts anticipated as a result of this project is required. The type
and detail of analysis shall conform to the NC Division of Water Resource Policy on the assessment of
secondary and cumulative impacts dated April 10, 2004.
8. The NCDOT is respectfully reminded that all impacts, including but not limited to, bridging, fill, excavation
and clearing, and rip rap to jurisdictional wetlands, streams, and riparian buffers need to be included in the
final impact calculations. These impacts, in addition to any construction impacts, temporary or otherwise,
also need to be included as part of the 401 Water Quality Certification Application.
9. Where streams must be crossed, the NCDWR prefers bridges be used in lieu of culverts. However, we realize
that economic considerations often require the use of culverts. Please be advised that culverts should be
countersunk to allow unimpeded passage by fish and other aquatic organisms. Moreover, in areas where high
quality wetlands or streams are impacted, a bridge may prove preferable. When applicable, the NCDOT
should not install the bridge bents in the creek, to the maximum extent practicable.
10. Whenever possible, the NCDWR 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.
11. 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. To meet the requirements of NCDOT's NPDES permit NCS0000250, please refer
to the most recent version of the North Carolina Department of Transportation Stormwater Best Management
Practices Toolbox manual for approved measures.
12. Sediment and erosion control measures should not be placed in wetlands or streams.
13. Borrow/waste areas should avoid wetlands to the maximum extent practicaL Impacts to wetlands in
borrow/waste areas will need to be presented in the 401 Water Quality Certification and could precipitate
compensatory mitigation.
14. 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.
15. Based on the information presented in the document, the magnitude of impacts to wetlands and streams may
require a Nationwide Permit application to the Corps of Engineers and corresponding 401 Water Quality
Certification. Please be advised that a 441 Water Quality Certification requires satisfactory protection of
water quality to ensure that water quality standards are met and no wetland or stream uses are lost. Final
permit authorization will require the submittal of a formal application by the NCDOT and written concurrence
from the NCDWR. Please be aware that any approval will be contingent on appropriate avoidance and
minimization of wetland and stream impacts to the maximum extent practical, the development of an
acceptable stormwater management plan, and the inclusion of appropriate mitigation plans where appropriate.
16. 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.
17. 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.
18. Unless otherwise autharized, placement of culverts and other structures in waters and streams shall be placed
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 downstream of the above structures. The applicant is
required to provide evidence that the equilibrium is being maintained if requested in writing by the NCDWR.
If this condition is unable to be met due to bedrock or other limiting features encountered during construction,
please contact the NCDWR for guidance on how to proceed and to determine whether or not a permit
modification will be required.
19. 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 should 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.
20. If foundation test borings are necessary; it shall be noted in the document. Geotechnical work is approved
under Genera1401 Certification Number 4085/Nationwide Permit No. 6 for Survey Activities.
21. 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.
22. All work in or adjacent to stream waters shall be conducted in a dry work area. Approved BMP measures
from the most current version of the 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.
23. While the use of National Wetland Inventory (NWI) maps, NC Coastal Region Evaluation of Wetland
Significance (NC-CREWS) maps and soil survey maps are useful tools, their inherent inaccuracies require
that qualified personnel perform onsite wetland delineations prior to permit approval.
24. Heavy equipment should 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.
25. 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 should be properly designed, sized and installed.
26. Riparian vegetation (native trees and sl�rubs) 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. The 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 919-707-8786.