HomeMy WebLinkAboutScoping Comments_HL-0048_24-0131_11-22-23
November 22, 2023
MEMORANDUM___________________________________________________
To: Chris R. Spencer, City of Greensboro, Transportation Engineering Manager
Alexa Kennedy, WSP, Transportation Planner
From: Ryan Conchilla, NC Division of Water Resources, Transportation Permitting Branch
Subject: Scoping comments for HL-0048, Pedestrian Signal Improvement, Greensboro, Guilford County.
State Clearing House #24-0131
Reference your correspondence dated November 3, 2023 in which you requested comments for the referenced project.
Preliminary analysis reveals the potential for impacts to streams and jurisdictional wetlands in the project area. More
specifically, impacts to:
Stream Name River Basin Stream
Classification(s)
Stream Index
Number 303(d) Listing
Horsepen Creek Cape Fear WS-III, NSW 16-11-5-(0.5) Yes
South Buffalo Creek Cape Fear WS-V, NSW 16-11-14-2 Yes
North Buffalo Creek Cape Fear WS-V, NSW 16-11-14-1 Yes
Ryan Creek Cape Fear WS-V, NSW 16-11-14-2-3 Yes
Muddy Creek Cape Fear WS-V, NSW 16-11-14-1-3 No
Richland Creek Cape Fear WS-III, NSW 16-11-7-1 No
Philadelphia Lake, Buffaloe
Lake and White Oak Lake
Cape Fear WS-V, NSW 16-11-14-1-2 No
Further investigations at a higher resolution should be undertaken to verify the presence of other streams and/or
jurisdictional wetlands in the area. In the event that any jurisdictional areas are identified, the Division of Water
Resources requests that the applicant consider the following environmental issues for the proposed project:
Project Specific Comments:
1. The design plans shall provide treatment of the stormwater runoff through BMPs as detailed in the most
recent version of the North Carolina Department of Transportation Stormwater Program Manual, and the
Stormwater Best Management Practices Toolbox Manual. The BMPs should, to the MEP, be selected and
designed to reduce impacts of the target pollutants of concern (POCs) for the receiving waters.
2. Horsepen, South Buffalo and North Buffalo Creek are 303(d) waters of the State and on the 303(d) list for
impaired use for aquatic life. The NCDWR is very concerned with sediment and erosion impacts that could
result from this project. The NCDWR recommends that the most protective sediment and erosion control
BMPs be implemented in accordance with Design Standards in Sensitive Watersheds (15A NCAC 04B
.0124) or comparable BMPs to reduce the risk of further impairment to Horsepen, South Buffalo and North
Buffalo Creek. Post-construction stormwater BMPs should be selected and designed to the MEP, to reduce
target POCs in the 303(d) list for the receiving waters.
3. This project is within the Jordan Lake Watershed Basin. Riparian buffer impacts shall be avoided and
minimized to the greatest extent possible pursuant to 15A NCAC 2B.0267. New development activities
located in the protected 50-foot wide riparian areas within the basin shall be limited to “uses” identified
within and constructed in accordance with 15A NCAC.02B.0295. Buffer mitigation may be required for
buffer impacts resulting from activities classified as “allowable with mitigation” within the “Table of Uses”
section of the Buffer Rules or require a variance under the Buffer Rules. A buffer mitigation plan, including
use of the North Carolina Division of Mitigation 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 “allowable with mitigation” within the “Table of Uses” section of the Buffer Rules or
require a variance under the Buffer Rules.
Transportation General Project Comments:
1. 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. After the selection of the preferred alternative and prior to an issuance of the 401 Water Quality Certification,
the applicant 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 acre 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.
3. 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.
4. 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.
5. The NCDWR is very concerned with sediment and erosion impacts that could result from this project. The
applicant 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.
6. The applicant 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.
7. 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 applicant should
not install the bridge bents in the creek, to the maximum extent practicable.
8. 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.
9. 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 recent version of the North Carolina Department of
Transportation Stormwater Best Management Practices Toolbox manual for approved measures.
10. Sediment and erosion control measures should not be placed in wetlands or streams.
11. 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.
12. 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. Please refer to the most recent version of the North Carolina Department of
Transportation Stormwater Best Management Practices Toolbox manual for approved measures.
13. Impacts to wetlands and streams may require a 404 permit application to the Corps of Engineers and
corresponding 401 Water Quality Certification. Please be advised that a 401 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
applicant 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.
14. 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. Concrete shall be
handled in accordance with the NPDES Construction General Permit NCG010000.
15. 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.
16. Unless otherwise authorized, 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.
17. 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.
18. If foundation test borings are necessary; it shall be noted in the document. Geotechnical work is approved under
General 401 Certification Number 4085/Nationwide Permit No. 6 for Survey Activities.
19. 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.
20. 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.
21. 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.
22. 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.
23. 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.
24. 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. The applicant 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
Ryan Conchilla at ryan.conchilla@deq.nc.gov.