HomeMy WebLinkAbout20190397_Memorandum of Agreement_20100125Governor r NCDENR
Beverly Eaves Perdue
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Coleen H. Sullins
Director
January 25, 2010
MEMORANDUM
To: Greg Thorpe, NCDOT
From: Amy Euliss, NC Division of Water Quality, Office
Subject: Scoping comments on proposed improvements to NC 105 in Avery-Watauga County, State
Project No. WBS#37512.1.1, TIP R-2566.
Reference your correspondence dated December 28, 2009 in which you requested comments for the
referenced project. Preliminary analysis of the project reveals the potential for multiple impacts to
streams and jurisdictional wetlands in the project area. More specifically, impacts to:
Stream Name River Basin Stream
Classifications Stream Index
Number
Linville River Caldwell C;Tr 11-24-(1)
Little Grass Creek Caldwell C;Tr;ORW 11-29-2
Watauga River and
Unnamed Tributaries Watauga B;Tr;HQW 8-(1)
Valle Creek Watau a C;Tr* 8-4
Big Branch Watauga C* 8-14
Laurel Fork and
Unnamed Tributaries Watauga C* 8-10
*Waters or portions of waters within one mile and draining to HQW shall carry HOW classifications
Dee Freeman
Secretary
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 Quality requests that NCDOT consider the following environmental issues for the
proposed project:
Project Specific Comments:
1. In the Purpose and Need for this project, please define the need for a 4-lane divide facility beyond
the project being part of the Strategic Highway Corridor. The need should include traffic
analyses, and discuss why facilities with a smaller footprint will not meet the proposed need for
the project. The need should also clearly discuss the reasons for the high variation in the traffic
analyses presented in the Scoping document.
2. A robust post construction stormwater management plan shall be prepared for the entire length of
this project.
Transportation Permitting Unit One
1650 Mail Service Center, Raleigh, North Carolina 27699-1650 NorthCarOllna
Location: 2321 Crabtree Blvd„ Raleigh, North Carolina 27604 Naturally
Phone: 919-733-17861 FAX: 919-733-6893
Internet: hfpalh2o.enr.state.ne.us/ncwetlandsl
An Equal Opportunity 1 Affrmatve Action Employer
3. Linville River, Little Grassy Creek, Watauga River, Valley Creek, and all of their Unnamed
Tributaries Creek are Trout waters of the State. NCD WQ recommends that the most protective
sediment and erosion control BMPs be implemented to reduce the risk of turbidity violations in
trout waters. In addition, all disturbances within trout buffers shall be conducted in accordance
with NC Division of Land Resources and NC Wildlife Resources Commission requirements.
4. Review of the project reveals the presence of surface waters classified as C; High Quality Waters
of the State in the project study area including the Watauga River, its Unnamed Tributaries. Alsc
all or portions of Valley Creek, Big Branch, and Laurel Fork are within one mile and draining to
waters classified HQW. This is one of the highest classifications for water quality. Pursuant to
15A NCAC 2H. 1006 and 15A NCAC 2B.0224, NCDOT will be required to obtain a State
Stormwater Permit prior to construction except in North Carolina's twenty coastal counties.
5. Review of the project reveals the presence of surface waters classified as C;Tr; Outstanding
Resource Waters of the State in the project study area, including Little Grassy Creek. The water
quality classification of C; ORW is one of the highest classifications in the State. NCD WQ is
extremely concerned with any impacts that may occur to streams with this classification. It is
preferred that these resources be avoided if at all possible. If it is not possible to avoid these
resources, the impacts shall be minimized to the greatest extent possible. Given the potential for
impacts to these resources during the project implementation, NCDWQ requests that NCDOT
strictly adhere to North Carolina regulations entitled "Design Standards in Sensitive Watersheds"
(15A NCAC 04B .0124) throughout design and construction of the project. Pursuant to 15A
NCAC 2H. 1006 and 15A NCAC 2B.0224, NCDOT will be required to obtain a State
Stormwater Permit prior to construction except in North Carolina's twenty coastal counties.
General Project Comments:
1. The environmental document shall 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 assessment alternatives shall consider design criteria that reduce the impacts to
streams and wetlands from storm water runoff. These alternatives shall include road designs that
allow for treatment of the storm water runoff through best management practices as detailed in the
most recent version of NCDWQ Stormwater Best Management Practices, such as grassed swales,
buffer areas, preformed scour holes, retention basins, etc.
3. After the selection of the preferred alternative and prior to an issuance of the 401 Water Quality
Certification, 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 I acre to wetlands. In the event that mitigation is required, the
mitigation plan shall be designed to replace appropriate lost functions and values. The NC Ecosystem
Enhancement Program may be available for use as wetland mitigation.
4. In accordance with the Environmental Management Commission's Rules {I 5A NCAC 2H.0506(h)}
mitigation will be required for impacts of greater than 150 linear feet to any single stream. In the
event that mitigation is required, the mitigation plan shall be designed to replace appropriate lost
functions and values. The NC Ecosystem Enhancement Program may be available for use as stream
mitigation.
5. NCDWQ is very concerned with sediment and erosion impacts that could result from this project.
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.
6. If a bridge is being replaced with a hydraulic conveyance other than another bridge, NCDWQ
believes the use of a Nationwide Permit may be required. Please contact the US Army Corp of
Engineers to determine the required permit(s).
7. If the old bridge is removed, no discharge of bridge material into surface waters is allowed unless
otherwise authorized by the US ALOE. Strict adherence to the Corps of Engineers guidelines for
bridge demolition will be a condition of the 401 Water Quality Certification.
8. 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) shall 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 current version of
NCDWQ's Stormwater Best Management Practices.
10. 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.
11. 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 should 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.
12. 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 NCDWQ for guidance on
how to proceed and to determine whether or not a permit modification will be required.
13. 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.
14. If foundation test borings are necessary; it should be noted in the document. Geotechnical work is
approved under General 401 Certification Number 3624/Nationwide Permit No. 6 for Survey
Activities.
15. 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.
16. All 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 should be used to prevent excavation in flowing water.
17. Sediment and erosion control measures shall not be placed in wetlands and streams.
18. Borrow/waste areas shall avoid wetlands to the maximum extent practical. Impacts to wetlands in
borrow/waste areas could precipitate compensatory mitigation.
19. 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.
20. 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.
21. In most cases, NCDWQ prefers the replacement of the existing structure at the same location with
road closure. If road closure is not feasible, a temporary detour should 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 should 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.
22. 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.
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 Amy Euliss at (336) 771-4959.
cc: Monte Matthews, US Army Corps of Engineers, Raleigh Field Office
Federal Highway Administration
Chris Militscher, Environmental Protection Agency (electronic copy only)
Marla Chambers, NC Wildlife Resources Commission (electronic copy only)
Wet] ands/401_Transportation-Permitti ng_Unit•
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