HomeMy WebLinkAboutU-5010 (2)OF W A]�9Q
Michael F. Easley, Governor
t!i
\O
William G. Ross Jr., Secretary
UJ q
North Carolina Department of Environment and Natural Resources
p .�
Coleen H. Sullins, Director
Division of Water Quality
November 25, 2008
MEMORANDUM
To: Gregory J. Thorpe, Ph.D., Manager, NCDOT Project Development and Environmental Analysis
From: Polly Lespinasse, NC Division of Water Quality, Mooresville Regional Office
Subject: Scoping Comments on the Proposed Widening of US 1 from South of State Road 1148 to US 74
(Future 1 -74), Richmond County, WBS 41143, TIP U -5010
Reference your correspondence dated October 10, 2008 in which you requested comments for the referenced project.
Preliminary analysis of the project reveals the potential for impacts to surface waters (ponds) in the project area.
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 NC DOT consider the following environmental issues for the proposed project:
General Project 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
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 NC DWQ
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,
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 (15A 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. DWQ 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, DWQ believes the use of
a Nationwide Permit may be required. Please contact the US Army Corp of Engineers to determine the
required permit(s),
Mailing Address Phone (704) 663 -1699 Location One hCnrolSnz
610 East Center Avenue, Suite 301 Fax (704) 663 -6040 610 East Center Avenue, Suite 3011�1�r17/fJ
Mooresville, NC 28115 Mooresville, North Carolina
Internet., www,ncwatcrgyality.orp Customer Service 1 -877- 623 -6748
An Eaual Gpportunity'AHirmative, Action Employer— 50% Recycled110% Post Consumer Paper
Dr. Gregory J. Thorpe, Ph.D.
Page Two
7. 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.
8. Bridge supports (bents) shall not be placed in the stream when possible.
9. Whenever possible, the DWQ 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 allow for human and wildlife passage beneath the
structure, do not block fish passage and do not block navigation by canoeists and boaters.
10. 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 NC DWQ Stormwater Best
Management Practices,
11. 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.
12. 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.
13. 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 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.
14. 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 end of structures typically
decreases water velocity causing sediment deposition that requires increased maintenance and disrupts
aquatic life passage.
15. If foundation test borings are necessary, it should be noted in the document. Geotechnical work is approved
under General 401 Certification Number 3687 /Nationwide Permit No. 6 for Survey Activities.
16. 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.
17. All work in or adjacent to stream waters shall be conducted in a dry work area unless otherwise approved by
NC DWQ. 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.
18. Sediment and erosion control measures shall not be placed in wetlands and streams.
Dr. Gregory J. Thorpe, Ph.D.
Page Three
19. Borrow /waste areas shall avoid wetlands to the maximum extent practical. Impacts to wetlands in
borrow /waste areas could precipitate compensatory mitigation.
20. 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.
21. 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.
22. In most cases, the DWQ 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.
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.
Thank you for requesting our input at this time. The 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 Polly Lespinasse at (704) 663 -1699
Cc! Karen Reynolds, Project Planning Engineer, NCDOT PDEA