20050732 Ver 02_More Info Requested_20060726

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Michael F. Easley, Governor
William G. Ross Jr., Secretary
North Carolina Department of Environment and Natural Resources
Alan W. ffiimek, P.E. Director
Division of Water Quality
July 26, 2006
CERTIFIED MAIL: RETURN RECEIPT REQUESTED
NNP-Briar Chapel, LLC
Attn.: W. Mitch Barron, Vice President Newland Communities
5850 Fayetteville Road, Suite 201
Durham, NC 27713
Subject Property: Briar Chapel
DWQ EXP No. 05-0732v2
Chatham County
REQUEST FOR MORE INFORMATION-EXPRESS REVIEWPROGA"
Dear Mr. Barron:
On July 24, 2006, the Division of Water Quality (DWQ) received your stormwater management plan
through the Express Review Program for the above-referenced project. The DWQ has determined that
this information is incomplete and/or contains erroneous information. Please provide the additional
information requested below:
1. You are required to provide an Extended Detention [Constructed] Wetland, Bio-retention, or Wet
Detention Pond followed by forested filter strip. You submitted design plans for three wet
detention ponds. The use of extended detention wetlands. is recommended..
2. Please specify a timeline for the design submittal to DWQ for the four future stormwater BMPs
(WQ ponds #4-7) indicated on the plans.
Wet Detention Pond Design Issues
a. The drawdown period DWQ has calculated based on your orifice diameter, etc., appears to
be outside of the 2 to 5-day parameter.
b. Permanent pool surface area appears to be slightly undersized on WQ Pond #2.
c. DWQ recommends permanent pool depths between 3 and 6 feet. WQ Ponds #2 and #3
permanent pool depth exceed this, which causes the Division concern with future liability
issues since this is in a residential subdivision setting.
d. Please provide a planting plan for the littoral shelves.
4. Level Spreader vs. Pre-formed Scour Hole:
a. Please explain your justification for the use of pre-formed scour holes in lieu of the
conventional level spreader design. In addition, please explain your inlet and outlet
velocities and pipe sizing.
5. Forested Filter Strip:
a. Please review the design requirements for the forested filter strip. Your submittal must
include a vegetation plan. It is not clear whether the existing vegetation is of sufficient
stem density to provide the nutrient removal needed. Please refer to the DWQ guidance
document, Guidelines for Riparian Buffer Restoration (NC DENR. 2001.
401 Oversight /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] / Internet http://h2o.enr.state.nc.us/ncwetiands
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An Equal Opportunity/Affirmative Action Employer- 50% Recycled/10% Post Consumer Paper

Briar Chapel Stormwater Management Plan
Page 2 of 2
July 26, 2006
http://h2o.enr.state.nc.us/M/pdf/buffers.pdf), for assistance in developing the planting
plan.
b. Please include maintenance of the forested filter strip in your Operation and Maintenance
Agreement. Information on maintenance requirements can be found on page 79 of the
1999 Stormwater BMP Manual.
c. Please indicate how the forested filter strip will be protected in perpetuity.
Please respond within five (5) days of the date of this letter by sending five (5) copies of the above
information in writing. 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 Cynthia Van Der Wiele at (919)
715-3473 or Cyndi Karoly at [phone] if you have any questions regarding or would like to set up a
meeting to discuss this matter.
Sincerely,
J ` ecl-4
Cyndi Karoly,
401 Oversight/Express Review Permitting Unit
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cc: USACE Raleigh Regulatory Field Office
DWQ Raleigh Regional Office
File Copy
Central Files
Jeremy Finch, P.E., John R. McAdams Co., Inc., 2905 Meridian Pkwy., Durham, NC 27713