20072082 Ver 1_More Info Letter_20080505

OF \NA Michael P. Easley, vovemor
O? QG William G. Ross Jr., Secretary
y North Carolina Department of Environment and Natural Resources
-I Coleen Sullins, Director
Q Division of Water Quality
May 5, 2008
DWQ Project # 07-2082
Mecklenburg County
CERTIFIED MAIL: RETURN RECEIPT REQUESTED
Gateway Homes, LLC
Attn: Mr. Dave Ransenberg
11121 Carmel Commons Boulevard, Suite 350
Charlotte, NC 28226
Subject Property: Highway 29 Project
Mallard Creek [030711, 13-17-5, C]
REQUEST FOR MORE INFORMATION: STORMWATER MANAGEMENT PLAN
Dear Mr. Ransenberg:
On January 31, 2008, the Division of Water Quality (DWQ) issued a 401 Water Quality Certification with
additional conditions to fill or otherwise impact 288 linear feet of stream in order to construct the above
named project. In order to meet Condition 6 of the 401 Certification for this project, a stormwater
management plan, dated August 8, 2007 and revised on April 18, 2008, signed and sealed on April 22, 2008
by Mr. James W. Caldwell, P.E., of John R McAdams Co., Inc was received by the DWQ on April 28,
2008. The DWQ has determined that your stormwater management plan was incomplete as discussed
below.
Additional Information Requested:
1. Please clearly delineate the drainage area to each BMP (one color drainage map, and one copy
shall suffice). Please note that stormwater runoff from the entire project site shall be treated to
achieve 85% TSS removal prior to leaving the site or discharge to state waters. Runoff generated
onsite shall not bypass the stormwater treatment systems.
2. Please redesign all proposed BMPs (Wet Detentions Ponds) in accordance with the most current
version of the NC Division of Water Quality Stormwater Best Management Practices Manual.
3. Please complete and submit the most current version of the BMP Supplement Form for each BMP
along with all requested information in the Required Items Checklist. The BMP Manual and the
Supplement Forms are available at http://h2o.enr.state.nc.us/su/bmi) forms.htm
4. Please pay particular attention to the Major Design Elements listed on page 10-2 of the BMP
Manual.
No One
hCarolina
401 Oversight/Express Review Permitting Unit Naturally
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/newetlwids
An Equal Opportunity/Affirmative Action Employer - 50% Recycled/10% Post Consumer Paper
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Page 2 of 2
May 5, 2008
5. Also, please maximize the length of the flow path between the inlets and the outlets as much as
possible to avoid stormwater flow short-circuiting. A flow path length to width ratio of 3:1 is
recommended. Baffles extending above the temporary pool levels may be used where there are
site constraints.
6. For each BMP, please provide the BMP outlet discharge and velocity calculations for the 10-year
storm (Qlo, and Vlo). Exiting velocity from wet pond 1 in particular must be non-erosive (less
than 2ft/s) since it discharges directly to a wetland. Please also include photos of areas downslope
of the dissipater pads.
The DWQ will require the above additional information to finalize review of the stormwater
management plan for the subject property. Please provide the following information so that we may
continue to review your project.
This letter only addresses the stormwater application review and does not authorize any impacts to
wetlands or waters of the state. Please be aware the stormwater management plans must be approved. by
this office before the impacts specified in your 401 Certification occur. You are welcome to contact me
at 919-733-1786 if you have questions or would like to set up a meeting.
Sincerely,
ZZ
AAk
Cyndi Karoly, Supervisor
O1 Oversight/Express Review Permitting Unit
CBK/jg
cc: USACE Asheville Regulatory Field Office
Alan Johnson, DWQ Mooresville Regional Office
James Caldwell, P.E., The John R McAdams Co., Inc. 2905 Meridian Pkwy, Durham, NC 28226
File Copy
Central Files
Filename: 072082Highway29Project(Mecklen burg)_SW_Hold l.doc
¦ Complete items 1, 2, and 3. Also complete
item 4 if Restricted Delivery is desired.
¦ Print your name and address on the reverse
so that we can return the card to you.
¦ Attach this card to the back of the mailpiece,
or on the front if space permits.
1. Article Addressed to:
Gateway Homes, LLC
Attn: Mr. Dave Ransenburg
11121 Carmel Commons
Blvd,ste350 Charlotte,NC 28226
D WQ# 07-2082-Mecklenburg
A. Signature
? Agent
X C ? Addressee
B. Receivedd by (Prin/ted me) C. D to of elivery
5 O ? / C' Cb7
D. Is delivery address diffe(ent from item 1 V ? Is
If YES, enter delivery address below: ? No
3. S rvice Type
Certified Mail Express Mail
Registered Return Receipt for Merchandise
? Insured Mail C.O.D.
4. Restricted Delivery? (Extra Fee)
? Yes
2. Article Number
(rranster from service fabeo ?008 0150 0001 3901 2 7 8 8
UNITED STATES POSTAL SERVICE

• Sender: Please print your name, address, and ZIP+4 in this box •
NC DIAR Division of Water
Quality
401 Oversight/Express Unit
2321 Crabtree Boulevard suite250
Raleigh,NC 27604
First-Class Mail
Postage & Fees Paid
USPS
Permit No. G-10
If JI III IIItill 1111111111111111111111111)1till IIIIIII111111111