SR 1370 Tryon Road (2)

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October 17, 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 1370
Improvements, Wake County, State Project No 8 2409101, TIP No U-4432, DENR
Clearinghouse No 09-00840
This office has reviewed the referenced document dated received September 30, 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 may not result in impacts to jurisdictional wetlands, streams, riparian buffers and other surface
waters However, if the project does, the DWQ offers the following comments based on review of the
aforementioned document
Project Specific Comments:
1 Swift Creek and its tributaries are class WS-III, NSW waters of the State DWQ is very concerned
with sediment and erosion impacts that could result from this project DWQ recommends that the most
protective sediment and erosion control BMPs be implemented to reduce the risk of nutrient runoff to
Swift Creek DWQ requests that road design plans provide treatment of the storm water runoff through
best management practices as detailed in the most recent version of NC DWQ Stormwater Best
Management Practices
2 This project is within the Neuse River Basin Riparian buffer impacts shall be avoided and minimized
to the greatest extent possible pursuant to 15A NCAC 2B 0233 New development activities located in
the protected 50-foot wide riparian areas within the basin shall be limited to "uses" identified within and
constructed in accordance with 15A NCAC 2B 0233 Buffer mitigation maybe required for buffer
impacts resulting from activities classified as "allowable with mitigation" within the "Table of Uses"
section of the Buffer Rules or require a variance under the Buffer Rules A buffer mitigation plan,
including use of the NC Ecosystem Enhancement Program, must be provided to DWQ prior to approval
of the Water Quality Certification
General Comments:
Any 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
NJo thCarohna
Transportation Permitting Unit ` ' atuCallY
1650 Mail Service Center, Raleigh, North Carolina 27699-1650
2321 Crabtree Boulevard, Suite 250, Raleigh, North Carolina 27604
Phone [phone] / FAX [phone] Internet http //h2o enr state nc us/ncvvetlands
Michael F Easley Governor
William G Ross Jr Secretary
North Carolina Department of Environment and Natural Resources
Coleen H Sullins, Director
Division of Water Quality
An Equal Opportunity/Affirmative Action Employer - 50% Recycled/10% Post Consumer Paper
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 Stormwater Best Management Practices, such as grassed swales, buffer
areas, preformed scour holes, retention basins, etc
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
4 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
If any 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
Moreover, in areas where high quality wetlands or streams are impacted, a bridge may prove
preferable When applicable, DOT should not install the bridge bents in the creek, to the maximum
extent practicable
6 Sediment and erosion control measures shall not be placed in wetlands, streams or riparian buffers
7 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
8 Any 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
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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 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
13 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
14 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
15 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
16 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
17 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
18 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 Eric Alsmeyer, US Army Corps of Engineers, Raleigh Field Office
Kathy Matthews, Environmental Protection Agency
Travis Wilson, NC Wildlife Resources Commission
Gregory J Thorpe, PhD, NCDOT PDEA
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