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Home My WebLink About20190531 Ver 2_Pre-Filing Meeting Information_20210630 State of North Carolina | Environmental Quality 1617 Mail Service Center | Raleigh, North Carolina 27699-1617 ROY COOPER Governor MICHAEL S. REGAN Secretary LINDA CULPEPPER Interim Director December 6, 2017 MEMORANDUM ____ TO: Chad Coggins, NCDOT Division 4 FROM: Rob Ridings, NCDWR Transportation Permitting Branch SUBJECT: Scoping Review of NCDOT’s Proposed Bridge Replacement Projects: Bridge 64 on SR 1126 over Town Creek, Edgecombe County In reply to your correspondence received December 6, 2017 in which you requested comments for the above referenced project, the NC Division of Water Resources offers the following comments: Project-Specific Comments 1. Town Creek is class C; NSW waters of the State. NCDWR is very concerned with sediment and erosion impacts that could result from this project. NCDWR recommends that highly protective sediment and erosion control BMPs be implemented to reduce the risk of nutrient runoff to Town Creek. NCDWR requests that road design plans provide treatment of the storm water runoff through best management practices as detailed in the most recent version of NCDWR’s Stormwater Best Management Practices. 2. This project is within the Tar-Pamlico River Basin. Riparian buffer impacts shall be avoided and minimized to the greatest extent possible pursuant to 15A NCAC 2B.0259. General Comments Regarding Bridge Replacement Projects 3. The NCDWR 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. 4. If foundation test borings are necessary; it shall be noted in the document. Geotechnical work is approved under General 401 Certification Number 3883/Nationwide Permit No. 6 for Survey Activities. 5. If a bridge is being replaced with a hydraulic conveyance other than another bridge, the NCDWR believes the use of a Nationwide Permit may be required. Please contact the US Army Corp of Engineers to determine the required permit(s). 6. If the old bridge is removed, no discharge of bridge material into surface waters is allowed unless otherwise authorized by the US ACOE. Strict adherence to the Corps of Engineers guidelines for bridge demolition will be a condition of the 401 Water Quality Certification. 7. Whenever possible, the NCDWR prefers spanning structures. Spanning structures usually do not require work within the stream or grubbing of the stream banks and do not require stream channel realignment. The horizontal and vertical clearances provided by bridges allow for human and wildlife passage beneath the structure, do not block fish passage and do not block navigation by canoeists and boaters. 8. 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 NCDW R Stormwater Best Management Practices. 9. 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. 10. Bridge supports (bents) shall not be placed in the stream when possible. 11. If temporary access roads or detours are constructed, the site shall be graded to its preconstruction co ntours 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. 12. 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. 13. All work in or adjacent to stream waters shall be conducted in a dry work area unless otherwise approved by the NCDWR. 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. 14. 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. 15. In most cases, the NCDWR prefers the replacement of the existing structure at the same location with road closure. If road closure is not feasible, a temporary detour shall 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 shall 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 ripari an areas. 16. Any anticipated dewatering or access structures necessary for construction of bridges should be addressed in the CE. It is understood that final designs are not determined at the time the CE is developed. However, the CE should discuss the potential for dewatering and access measures necessary due to bridge construction. General Comments if Replacing the Bridge with a Culvert 17. 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 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. 18. 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 shall be avoided. Stream channel widening at the inlet or outlet e nd of structures typically decreases water velocity causing sediment deposition that requires increased maintenance and disrupts aquatic life passage. 19. Riprap shall not be placed in the active thalweg channel or placed in the streambed in a manner that pre cludes aquatic life passage. Bioengineering boulders or structures shall be properly designed, sized and installed. 20. Any anticipated bank stabilization associated with culvert installations or extensions should be addressed in the Categorical Exclusion (CE) document. It is understood that final designs are not determined at the time the CE is developed. However, the CE should discuss the potential for bank stabilization necessary due to culvert installation. Thank you for requesting our input at this time. The DOT 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.