20081161 Ver 1_General Correspondence_20080220

WATF~Q Michael F. Easley, Governor
William G. Ross Jr., Secretary
`0 ~ North Carolina Department of Environment and Natural Resources
co r~ Alan W. Klimek, P.E. Director
> = I Division of Water Quality

February 20, 2008

MEMORANDUM

TO: Joseph Kelvington, Stantec Consulting Services

FROM: Rob Ridings, NC Division of Water Quality, Transportation Permitting Unit

SUBJECT: Scoping Review of NCDOT's Proposed Bridge Replacement Project: B- 4585, Nash County
In reply to your correspondence dated February 12, 2008 (received February 14, 2008) in which you requested comments
for the above referenced project, the NC Division of Water Quality offers the following comments:

Project-Specific Comments

B-4585, Bridge Numbers 65 and 66, Over Toisnot Swamp, Nash County

1. Toisnot Swamp is 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 highly protective sediment and erosion control
BMPs be implemented to reduce the risk of nutrient runoff to Toisnot Swamp. 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 NeuseRiver Basin. Riparian buffer impacts shall be avoided and minimized to the
greatest extent possible pursuant to 15A NCAC 2B.0233.

General Comments Regarding Bridge Replacement Projects

1. 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.
2. If foundation test borings are necessary; it shall be noted in the document. Geotechnical work is approved under
General 401 Certification Number 3494/Nationwide Permit No. 6 for Survey Activities.

3. If the old bridge is removed, no discharge of bridge material into surface waters is allowed unless otherwise
authorized by the USACOE. Strict adherence to the Corps of Engineers guidelines for bridge demolition will be a
condition of the 401 Water Quality Certification.

4. Whenever possible, the DWQ 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. One
N.,o~Carolina
Transportation Permitting Unit tllCR~;
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.uslncvvetlands
An Equal Opportunity/Affirmative Action Employer- 50% Recycled/10% Post Consumer Paper

and
Stormwater shall be directed across the bridge
before
e directly into the stream vegetated buffers, etc.)
assed swales, pre-formed scour holes, Management practices.
5. Bridge deck drains shall not discharge
version re NC DWQ Stormwater Best re-treated through site-appropriate means (gr
p the stream. Please refer to the most current Prevent direct contact between curing
entering
6. l not be discharged to surface
construction, a dry work area shall be maintained to p
cts uncured concrete shal
if concrete used during uatic life and fish kills.
concrete and stream water. Water that inadvertently conta
ters due to the potential for elevated pH and possible aq
v'a ossible.
Bridge supports (bents) shall not be placed in the stream when p
aded to its preconstruction contours sand
pecies
access roads or detours are constructed, the site shall be
. Clearing the area with
g. If temporary Disturbed areas shall be seeded or mulched to stabilize the soil and appropriate native woody elevations. Dis structures the area shall be cleared btuhe o not ps anbbedd root mat intact allows
shall be planted. When using temporary ui ment and leaving
mowers, bush-hogs, or other mechanized eq p
chain saws,
the area to re-vegetate naturally and minimizes soil disturbance.
resources must be implemented and maintained in
otect water
ime n of North Carolina Sediment and Erosion Cl Planning and Design
nt and erosion control measures sufficient to pr ontro
9. Sed
accordance with the most recent versio
manual and the most recent version of NCS000250. work area unless otherwise approveroved b by NC ntenance acent to stream waters shall be conducted in a' ersion structures shall be used to prevent
0. All work in or adj s from the most current version of Ne DOT Construction and Mai
1
DWQ Approved BMP measure rock berms, cofferdams and of
Activities manual such as sandbags
excavation in flowing water.
bank rather than in stream channels in order to minimize sedimentation
ent shall be inspected daily and
e ui ment shall be operated from the
11. Heavy q p other pollutants into streams. This equip draulic fluids, or other toxic
n n surface waters from leaking fuels, lubricants, by
1 and reduce the likelihood of introducing
maintained to prevent contaminatio
In most location with road closure. If
materials. structure at the same
replacement of the existing
- t cases, the DWQ prefers the shall be designed and located to i 1 avoid wetnd be on a new m ~ acts, meat, minimize
will
12. If the structure
road closure is not feasible, a avoid delta detour ear floodplain. Approach fills shall be temporary and to avoid destabilizing stream banks.
ass and planted with native
the need for clearingrnoved and the approach fills removed from the 100-y
structure shall be re ground elevation. The area shall be stabilized with gr
removed and restored to the natural riparian areas.
on of the
tree species. Tall fescue shall not be used in es in waters, - dins and wetlands shall be below th of the culvert diameter
ercent and
greater than 48 inches, and 20 p uatic
13. Placement of culvertst and
aother ll culverts with a diameter gr allow ea low flow passage of water and aq
for culverts eone life. Design
re
a diameter less than 48 inches, to m orary erosion control measures shall o upstream n
fhaving foot
temporary
adjacent to
tures including
placeme and Gown
nt of culverts and other struc a
uilibrium of wetlands or streambe rovide ds or evidence banks, that the equilibrium is being
pr
manner that may result in ores. applicant is required to
stream of the above structures. The W If this condition is unable to be da rice on~how to ck or othproceeder and to limiting
maintained if requested in writing by D lease contact the NC DWQ for gu
features encountered during construction, p
determine whether ification will be required. cross section as closely as
ether or not a permit mod
stream
shall be designed to manic natural stream
wired, they ro riate. Widenin dtheecreases water
14. If multiple pipes or barrels are req lain elevation and/or sills where app p ically
pollible including Pipes or barrels at flood plain gat the inlet or outlet enddo d ruptur attic life passage.
channel shall be avoided. Stream channel
causing sediment deposition that requires increased maintenance ail
velocity
anriel or placed in the streambed in a sized and installed des
laced in the active thalweg ch be properly designed,
15. Riprap shall not be p ineering boulders or structures shall aquatic life passage. Bioeng

Certification
designated uses are not
at this time. The DOT is reminded that t ndards are met and desQign1Ty u for requesting our input 733-
Thank requires yo that appropriate measures be instituted equire add tional informa on, please contact Rob Ridings at (919)
req have any questio
degraded or lost. If you
9817.
Corps of Engineers, Washington Field office
cc: William Wescott . .sion 4 Environmental Officer
Chad Cogg e Management Unit
Mike Summers, NCDOT Bridg
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