HomeMy WebLinkAbout20041808 Ver 2_Memorandum of Agreement_20090622NCDENR
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Beverly Eaves Perdue Coleen H. Sullins Dee Freeman
t;nvarnnr rlirartnr Secretary
June 22, 2009
MEMORANDUM
To: Melba McGee, Environmental Coordinator, Office of Legislative and Intergovernmental Affairs
From: Polly Lespinasse, Division of Water Quality, Mooresville Regional Office
Subject: Comments on the Environmental Assessment Related to the Proposed Stanly County Airport
Improvements (Extension of Runway 04R-22L to 7,000 feet), Stanly County, Stanly County Airport
Authority in Association with the North Carolina Department of Transportation Division of
Aviation, State Clearinghouse Project No. 09-0353, Due Date 07/06/09
This office has reviewed the referenced document dated June 2009. The NC Division of Water Quality (NCDWQ) is
responsible for the issuance of the Section 401 Water Quality Certification for activities that impact Waters of the U.S.,
including wetlands. It is our understanding that the project as presented will result in impacts to jurisdictional wetlands,
streams, and other surface waters. NCDWQ offers the following comments based on review of the aforementioned
document:
Project Specific Comments:
Little Mountain Creek is a Class WS-IV; 303(d) Waters of the State. Little Mountain Creek is on the 303(d) list for
impaired use for aquatic life due to impaired biological integrity. 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 Little Mountain 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's
Stormwater Best Management Practices.
General Comments:
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 21-1.0506(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's Stormwater Best
Management Practices, such as grassed swales, buffer areas, preformed scour holes, retention basins, etc.
Mooresville Regional Office
Location: 610 East Center Ave., Suite 301 Mooresville, NC 28115
Phone: (704) 663-16991 Fax: (704) 663-60401 Customer service: 1-877-623-6748
Internet: vmv.ncwatetquality.org
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3. After the selection of the preferred alternative and prior to an issuance of the 401 Water Quality Certification, the
Stanly County Airport Authority and the NCDOT Division of Aviation are 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 should 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 perennial 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. Future documentation, including the 401 Water Quality Certification Application, should continue to include an
itemized listing of the proposed wetland and stream impacts with corresponding mapping.
6. NCDWQ is very concerned with sediment and erosion impacts that could result from this project. The Stanly
County Airport Authority and the NCDOT Division of Aviation 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 Quality Policy on the assessment of secondary and
cumulative impacts dated April 10, 2004.
8. The Stanly County Airport Authority and the NCDOT Division of Aviation are 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, NCDWQ 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 shall 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, NCDOT should not install the bridge bents
in the creek, to the maximum extent practicable.
10. 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.
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. Please refer to the most current version ofNCDWQ's Stormwater Best Management Practices.
12. Sediment and erosion control measures shall not be placed in wetlands or streams.
13. Borrow/waste areas shall 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
an Individual Permit (IP) 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 Stanly County Airport Authority and/or the
NCDOT Division of Aviation and written concurrence from NCDWQ. 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. Placement of culverts and other structures in waters, streams, and wetlands 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 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.
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 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.
20. If foundation test borings are necessary; it shall be noted in the document. Geotechnical work is approved under
General 401 Certification Number 3687/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 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 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 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 should 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 shall be properly designed, sized and installed.
26. 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.
NCDWQ appreciates the opportunity to provide comments on your project. Shall you have any questions or require any
additional information, please contact Polly Lespinasse at (704) 663-1699.
cc: Steve Lund, US Army Corps of Engineers, Asheville Field Office (electronic copy)
Chris Militscher, Environmental Protection Agency (electronic copy)
Marla Chambers, NC Wildlife Resources Commission (electronic copy)
Marella Buncick, US Fish and Wildlife Service (electronic copy)
Sonia Gregory, NCDWQ Central Office (electronic copy)
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