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December 21, 2007
EXPRESS REVIEW NOTIFICATION LETTER
East Durham Development Company, LLC
Attn: Mr. Michael Whitehead
201 Shannon Oaks Circle
Raleigh, NC 27511
Project Name: Sierra Residential Subdivision
Dear Mr. Whitehead:
Michael F. Easley, Governor
William G. Ross Jr., Secretary
North Cazolina Department of Environment and Natural Resources
Coleen H. Sullins, Director
Division of Water Quality
Durham County
EXP# 07-2022
On December 19, 2007, the Express Review Program of the Division of Water Quality (DWQ) received your
application for 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 submitted application is for a residential subdivision, NW29 (GC 3705). You have currently submitted a
partial application (only including the road structures). Large subdivision projects can be phased,
geographically by quadrants, but not as you have submitted. It is recommended that an office meeting be
conducted after January 1, 2008 (preferably on January 2°a) in order to clarify the numerous items detailed
below. The express clock will stop for the holidays at Spm of December 21, 2007 and restart again on January
2, 2007.
2. Please follow the guidelines in the PCN addendum.
a. As per the guidelines, site "plans must show all built-out structures and impervious cover. The plans
must include the final grading contours with elevations. The plans must indicate all utilities and
easements".
b. Additionally, platted parcels must be developable without further impacts to jurisdictional and non-
jurisdictional wetlands, streams, water features, and State regulated buffers. These parcels must be
shown in order to determine that no further impacts will occur.
c. Please clearly depict all of the wetland boundaries on the property.
d. Please provide maps (at least 1:100) in sufficient detail to observe all parcels and features.
3. Diffuse Flow Provisions:
a. Every proposed BMP structure for stormwater management or diffuse flow provisions shall be
permanent, and not temporary. If a temporary BMP is needed for phase I and will be removed during
future phases of development, please understand that a new (and appropriate) BMP must be approved
by the DWQ and be installed before any existing BMP is removed.
b. All buffer widths shall be measured from top of bank on both sides of all streams. Please show the top
of bank along all streams on plans along with both Zones (1 & 2) of riparian buffer.
c. Please site and design level spreaders in accordance with the current North Carolina Stormwater Best
Management Practices Design Manual available at http://h2o.enr.state.nc.us/su/bmp fortns.htm.
Please pay particular attention to the following items:
401 Oversightl 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/ncwetlands
An Equal OpportunitylAffirmative Action Employer- 50% Recycledl10% Post Consumer Paper
N ne Carolina
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i. Locating devices to follow existing contours.
ii. Avoiding steep slopes (Maximum 8% for grass filter strip and 6% for forest filter strip).
Slopes were measured to range between 16% and 20%.
iii. Avoiding draws down slope of level spreaders.
iv. Level spreaders shall be designed for 1 "/hr storm with bypass for the 10-yr storm or for the
10-yr storm without bypass.
v. Maximum length for any level spreader shall be 136 ft.
d. Please delineate the drainage areas to the level spreaders, indicating amount of impervious area for
each drainage area, and submit design flow calculations for the 1 "/hr and 10-yr storm.
e. Bypass structures shall be directed away from the level spreaders.
£ Please reconcile the level spreader table shown on plan sheet C703 and that in the main application
document. In addition, some level spreaders are not shown on the plans. These include those with end
sections FES 9, 21, 27, 33, 58, 64 and 68.
g. Please submit a level spreader supplement form for each level spreader, including the Design
Summary and Required Items Checklist along with all requested items.
h. Please submit one original and two copies of a notarized Inspection and Maintenance Agreement
Form for the proposed level spreaders.
i. If level spreaders are designed to receive flow from any BMP, please indicate BMP types and
locations, and include BMP outflow calculations.
j. Please see Option 2 of the Stormwater Management for Buffer Rules Section of the PCN
Addendum and also Section 8.3.6 of the NC BMP Manual (page 8-8) for guidance on other BMP
options where level spreaders are not appropriate.
k. Please include velocity dissipator design sheets.
Please respond within five (5) days of the date of this letter by sending three (3) copies of this information. 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 contact Lia Myott at [phone] if you have any questions.
Sincerely,
~~
Cyndi Karoly, Supervisor
401/Express Review Oversite Unit
CBK/lem
cc: DWQ Raleigh Regional Office
USAGE Raleigh Field Office
Central Files
File copy
Mr. John E. Schrum, Horvath Associates P.A., 16 Consultant Place, Suite 201, Durham, NC 27707