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HomeMy WebLinkAbout20110978 Ver 1_Staff Comments_20081124W A r Michael F Easley, Governor F Q 9 QC? QG William G Ross Jr, Secretary North Carolina Department of Environment and Natural Resources \ Cq r Coleen H Sullins, Director Division of Water Quality November 24, 2008 MEMORANDUM To Melba McGee, DENR Environmental Coordinator From Rob Ridings, Division of Water Quality, Transportation Permitting Unit Subject Comments on the Finding of No Significant Impact related to proposed SR 1596 widening from US 401 Business to SR 1400, Cumberland County, Federal Aid Project No STP-1592(2), State Project No 35024 1 1, TIP No U-4422, DENR Clearinghouse No 09-0131 This office has reviewed the referenced document dated received November 17, 2008 The Division of Water Quality (DWQ) 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 junsdictional wetlands, streams, and other surface waters The DWQ offers the following comments based on review of the aforementioned document General Comments: The permit application 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 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 Stormwater Best Management Practices, 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 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 {1 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 Noce Carohna Transportation Permitting Unit Naturally 1650 Mad Service Center, Raleigh, North Carolina 27699-1650 2321 Crabtree Boulevard, Suite 250, Raleigh, North Carolina 27604 Phone 919-733-17861 FAX 919-733-6893 / Internet http //h2o enr state nc us/ncvvetlands An Equal Opportunity/Affirmative Action Employer- 50% Recycled/10% Post Consumer Paper 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 DWQ is very concerned with sediment and erosion impacts that could result from this project NC DOT 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 NC DOT is respectfully reminded that all impacts, including but not limited to, bndgmg, fill, excavation and clearing, 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 Where streams must be crossed, the DWQ 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 \ Sediment and erosion control measures shall not be placed in wetlands or streams 10 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 11 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 12 Based on the information presented in the document, the magnitude of impacts to wetlands and streams may require Nationwide (NW) 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 NCDOT and written concurrence from the 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 13 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 lulls 14 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 15 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 DWQ If this condition is unable to be met due to bedrock or other limiting features encountered during construction, please contact the NC DWQ for guidance on how to proceed and to determine whether or not a permit modification will be required 16 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 and/or sills 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 17 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 18 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 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 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 22 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 The NCDWQ appreciates the opportunity to provide comments on your project Should you have any questions or require any additional information, please contact Rob Ridings at (919) 733-9817 cc Richard Spencer, US Army Corps of Engineers, Wilmington Field Office Jim Rerko, Division 6 Environmental Officer Gregory Thorpe, Ph D , NCDOT PDEA DWQ Fayetteville Regional Office File Copy