20011549 Ver 1_More Info Letter_20020816

?0F WATF,?Q Michael
G
y William G. Ross, Jr., Sec
r Department of Environment and Natural ReSOI
> -I
Alan W. Klimek, P.E. Direc
Division of Water Quality
_ s
August 16, 2002
Mr. Ken Jesneck, PE
Withers and Ravenel
111 MacKenan Dr.
Cary, NC 27511
Subject: Long Lake Subdivision
DWQ Project No. 011549
Wake County
Dear Mr. Jesneck:
The Wetlands Unit staff reviewed the stormwater management plans for the subject project and determined that additional
information is necessary to complete the technical review process. The required additional information is as follows:
Draw Down Orifice Outlet
The orifice on Pond E at the "T appears to be below the permanent pool elevation. It is not clear if it will be capped.
Please clarify.
2. Inlet/Outlet Structure Location
The inlet and outlet structures of Ponds A and C must be placed to minimize short circuiting and turbulence. A long
flow path will help to maximize the settling efficiency of the water quality structure. The submitted design will be
subject to short circuiting. This issue may be addressed through contouring, structure relocation, baffles, etc.
3. Vegetated Side Slopes
The dry basin (Pond D) basin side slopes must be stabilized with vegetation and side slopes no steeper than 3:1
(horizontal to vertical). If this is not possible then the slopes must be stabilized with erosion control fabric that allows
vegetation to establish.
Division wetlands unit staff will strive to complete a final technical review within 10 working days of receipt of the
requested information. If you have any questions or would like to discuss this project, please contact me at (919) 733-
9584. Also, please note that the NCDENR Stormwater 4est Management Practices. Manual, April 1999, and other
documents and information can be downloaded from the Wetlands Unit web site at
hftp7flh2o.ehnr.state.nc.us/ncwetlands/.
Verejy?
/0 St. John, PE
Environmental Engineer
cc: Raleigh Regional Office
File
North Carolina Division of Water Quality, 401 Wetlands Certification Unit,
1650 Mail Service Center, Raleigh, NC 27699-1650 (Mailing Address)
2321 Crabtree Blvd., Raleigh, NC 27604-2260 (Location)
919-733-1786 (phone), 919-733-6893 (fax), http://h2o.enr.state.nc.us/ncwettands/