20070081 Ver 2_More Info Letter_20070724

~~~ W A TF,QQ Michael F. Easley, Governor
`~ ~i William G. Ross Jr., Secretary
Cq tom.- North Cazolina Department of Environment and Natural Resources
~ ~ Coleen H. Sullins, Director
Division of Water Quality
July 24, 2007
DWQ EXP No. 07-0081v2
Wake County
CERTIFIED MAIL: RETURN RECEIPT REQUESTED
Mr. Robert Polanco
8804 Albright Road
Raleigh, NC 27612
Subject Property: Cedar Ridge Subdivision, Rolesville, NC
Harris Creek [030402, 27-26, C NSW]
REQUEST FOR MORE INFORMATION-EXPRESS REVIEW PROGRAM
Dear Mr. Polanco:
On July 20, 2007, the Express Review Program of the Division of Water Quality (DWQ) received a
response to our July 11, 2007 letter requesting more information regarding the above referenced project.
The DWQ has determined that your application will require additional information.
Please provide the following information so that we may continue to review your project and prevent
denial of your application as required by 15A NCAC 2H .0506:
1. The inlet velocities for all 12 of the proposed bioretention areas are too high. The inlet
velocity may not exceed 1.0 foot per second during the 10-year, 24-hour storm. Please
provide appropriate velocity dissipation devices to bring the velocities down to the allowable
range. Also, please submit updated worksheets for the bioretention areas that reflect this
design change.
2. The reported drawdown rates do not appear to have been calculated properly (i.e., they seem
to have been underestimated). Please check this and resubmit the bioretention worksheets
with corrections if needed.
3. Please recompute the required treatment volume for the bioretention areas using the Simple
Method as required per the new BMP Manual and size the bioretention areas appropriately.
See attached spreadsheet.
4. Sheet 9A of 35 Landscape Notes. You have provided typical details of bioretention planting
plans. Please provide an accurate planting plan for each individual biorentention area (these
should look similar to the typical planting details).
Please respond within five (5) days of the date of this letter by sending three (3) copies of the above
information in writing. The Express Review Program is a process that requires all parties to participate in a
timely manner.
This letter only addresses the application review and does not authorize any impacts to wetlands, waters
or protected buffers. Please be aware that any impacts requested within your application are not
authorized (at this time) by the DWQ. Please contact Lia Myott at [phone] if you have any
questions regarding or would like to set up a meeting to discuss this matter.
401 Oversight I Express Review Permitting Unit
1650 Mail Service Center, Raleigh, North Carolina 27699-1650
2321 Crabtree Boulevard, Suite 250, Raleigh, North Carolina 27604
Phone: [phone] FAX [phone]ntemet: htto://h2o.enr.state.nc.uslncwetlands
Non° Carolina
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An Equal OpportunitylAffirmativeRction Employer - 50% Recycled110% Post Consumer Paper

Cedar Ridge Subdivision
Page 2 of 2
July 24, 2007
Sincerely,
Cy di Karoly, Supervisor
401 Oversight/Express Review Permitting Unit
CBK/lem
Enclosures: Spreadsheet for bioretention area water quality volumes
cc: USACE Raleigh Regulatory Field Office
DWQ Raleigh Regional Office
File Copy
Central Files
Jay Keller, Keller Environmental, 7921 Haymarket Lane, Raleigh, NC 27615
Harold Yelle, Aiken and Yelle Assoc., PA, 3755 Benson Drive, Raleigh, NC 27609
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