20091020 Ver 1_More Info Received_20100329

Gyamfi, Joseph
From: Chris Manes [[e-mail]]
Sent: Monday, March 29, 2010 3:17 PM
To: Gyamfi, Joseph; Barnett, Kevin
Cc: Jeff Belyea
Subject: RE: Marion Wal-Mart Additional Information
Joseph,
Attached to this email is a PDF of the revised sheets that we spoke of on the telephone. The PDF includes a revises sheet
3 out of the O&M agreement depicting the proper depth readings in the forebay and main pond. The other two sheets
are the revised supplement form showing the temporary pool volumes only and correcting the pool elevations. If you
need any additional information please feel free to give me a call.
Thanks,
Chris Manes, P.E., CPESC
Site Department
Wolverton & Associates, Inc.
6745 Sugarloaf Parkway
Suite 100
Duluth, GA 30097
770-447-8999 phone
770-447-9070 fax
chris. manes(cDwolverton-assoc. com
www.wolverton-assoc.com
From: Jeff Belyea
Sent: Monday, March 29, 2010 1:59 PM
To: Chris Manes
Subject: FW: Marion Wal-Mart Additional Information
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From: Gyamfi, Joseph [mailto:[e-mail]]
Sent: Monday, March 29, 2010 1:06 PM
To: Jeff Belyea
Cc: Barnett, Kevin; Gyamfi, Joseph
Subject: RE: Marion Wal-Mart Additional Information
Hi Jeff,
I have reviewed the information received on February 10, 2010. Here are the missing information:
(1) Sections I and II of the Supplement Form;
(2) Detailed percent impervious calculations of the drainage areas on the site;
(3) Pond design/sizing information including surface area, average depth, temporary pool (water quality) volume
required versus provided, drawdown time, sizing of the emergency spillway, etc.
(4) Page 3 of the Operation & Maintenance agreement must be revised. Sediment shall be removed when the pool
depth reads 9ft (in the main pool) and Oft (in the forebay).
Please let us know when you can get the above information to us, else we must write a request for additional
information so as to restart the clock from our end. We will need a hardcopy in the mail, but you can email me (and
1
copy Kevin) the requested information so I can continue with the review. Let me know if you have any questions.
Thanks.
Joseph
From: Jeff Belyea [mailto:[e-mail]]
Sent: Thursday, March 25, 2010 4:27 PM
To: Gyamfi, Joseph
Cc: Barnett, Kevin
Subject: RE: Marion Wal-Mart Additional Information
Joseph,
Anything you can do to expedite this would be greatly appreciated.
Thank you for your assistance.
Jeff Belyea, P.E.
Site Department
Wolverton & Associates, Inc.
6745 Sugarloaf Parkway
Suite 100
Duluth, GA 30097
770-447-8999 phone
770-447-9070 fax
ieff. belvea()-wolverton-assoc. com
www.wolverton-assoc.com
From: Gyamfi, Joseph [mailto:[e-mail]]
Sent: Thursday, March 25, 2010 4:24 PM
To: Jeff Belyea
Cc: Barnett, Kevin
Subject: RE: Marion Wal-Mart Additional Information
Jeff,
I'll try and get the file so I can review the information we received recently. That way, we can all be assured that you
have provided us with all the requested documents and so there's no additional information we may need. I'll put it on
my calendar and take a look at it early next week. I hope this helps. Have a great day.
Joe
---------------------
---------------------
Joseph Gyamfi, P.E., P.Eng.
Environmental Engineer
NCDENR/DWQ
401/Express Permitting Unit
2321 Crabtree Blvd., Suite 250, Raleigh, NC 27604
Phone: [phone]
Fax: [phone]
Website: http://h2o.enr.state.nc.us/ncwetlands/index.htmi
2
Permit Number:
(to be provided by DWQ)
Drainage Area Number:
BMP element: Potential problem: How I will remediate the problem:
The.embankment Shrubs have started to grow Remove shrubs immediately.
on the embankment.
Evidence of muskrat or Use traps to remove muskrats and
beaver activity is present. consult a professional to remove
beavers.
A tree has started to grow on Consult a dam safety specialist to
the embankment remove the tree.
An annual inspection by an Make all needed repairs.
appropriate professional
shows that the embankment
needs repair. if applicable)
The outlet device Clogging has occurred. Clean out the outlet device. Dispose
of the sediment off-site.
The outlet device is damaged Repair or replace the outlet device.
The receiving water Erosion or other signs of Contact the local NC Division of
damage have occurred at the Water Quality Regional Office, or
outlet. the 401 Oversight Unit at 919-733-
1786.
The measuring device used to determine the sediment elevation shall be such
that it will give an accurate depth reading and not readily penetrate into
accumulated sediments.
When the permanent pool depth reads 9 feet in the main pond, the sediment
shall be removed.
When the permanent pool depth reads 4 feet in the forebay, the sediment shall
be removed.
BASIN DIAGRAM
(fill in the blanks)
Sediment Removal
Bottom
Permanent Pool Elevation 1408
1404 1
--------------- -
FOREBAY
Cft Min.
Sediment
Storage
Pool
----- Sediment Removal Elevation 1399 ----------- Volum
Bottom Elevation
MAIN POND
1-ft
Storage
Form SW401-Wet Detention Basin O&M-Rev.4 Page 3 of 4
Permit No.
(do be provided by DWQ)
WDENR
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
WET DETENTION BASIN SUPPLEMENT
This form must be god out, prided and submited.
The Requked Rems Chwdst (Pad fit) must be printed, fined out end submitted afong with a# of the requited h mtaNon.
Project name ;,Grandview SlaWri Wth,Wal-Mart Supercenter#1
Contact person Bo Murphy'
y
Phone number Oy3?b4 7858^ ;
7777777
Date 1 11 91201 0
Drainage area number 1- fond 1
?o? warE9
a

Ste Characteristics
Drainage area 1 8 f 9,937: }?
Impervious area, post-development 1,019,740;f?
% Impervious 56-03%
Design rainfall depth 1.Oin
Storage Volume: Non-SA Waters
Minimum volume required
Volume provided
Storage Volume: SA Waters
1.5` runoff volume
Pre-development 1-yr, 24-hr runoff
Post-development 1-A 24-hr runoff
Minimum volume requited
Volume provided
Peak Flow Calculations
Is the preWpost control of the lyr 24hr storm peak flow required?
1-yr, 24-hr rainfall depth
Rational C, pre-development
Rational C, post-development
Rainfall Intensity: t-yr, 24-hr storm
Pre-development 1-yr, 24-hr peak flow
Post-development 1-yr, 24-hr peak flow
Pn:lPost 1-yr, 24-hr peals flow control
Elevations
Temporary pool elevation
Permanent pool elevation
SHWT elevation (approx, at the perm. pool elevation)
Top of 10ft vegetated shelf elevation
Bottom of 10ft vegetated shelf elevation
Sediment cleanout, top elevation (bottom of pond)
Sediment deanout, bottom elevation
Sediment storage provided
Is there additional volume stored above the state-required temp. pool?
Elevation of the top of the additional volume
84,064 fe OK
67 533a ga OK, volume provided is equal to or in excess of volume required.

„fta
fta
y (Y or N)
':3'f in
0.35: (unitless)
Q;67+ (unftless)
0;13'itllhr OK
11.84 folsec
5.34 ftalsec
-6.50 felsec
' 140859` fmsl
140t1 fmsf
1392.00'1 tm?
1408'50' imel
1407.50 fins) Data not needed for calculation option #1, but OK I provided.
-01*w
77, 1398.00;1msl Data not needed for calculation option #1, but OK I provided.
1.00 ft
n (Y or N)
fmsl
Form SW401-Wat Detention Basin-Rev.8-9117= Parts L & It. Design Summary. Page 1 of 2
Permit No.
(to be provided by AWC?
Volumes
Volume, temporary pool 87,633; ft OK
Volume, permanent pool, V 214,051' ftg
Volume, forebay (sum of forebays if more than one forebay) 44-" 335' ft'
Forebay % of permanent pod volume 20.7% %s OK
SAIDA Table Data
Design TSS removal ?? ?s`t 90? %
Coastal SAIDA Table Used? n (Y or N)
Mountain/Piedmont SAIDA Table Used? y (Y or N)
SAIDA ratio 259 (unitless)
Average depth (used in SAIDA table):
Calculation option 1 used? (See Figure 10-2b)
(Y or N)
Vol nie, permanent pod, V,,,_pm 214,057 fe
Area provided, permanent pod, Ap,,,,,,w 49,419 fiz
Average depth calculated 4.33' ft OK
Average depth used in SAIDA, d., (Round to nearest 0.5ft) 0; it OK
Calculation option 2 used? (See Figure 10-2b) J (Y or N)
Area provided, permanent pod, A.„-,,a 49,419 fr
Area, bottom of 10ftvegetated shelf, A%,w 41,744 ft
Area, sediment deanout, top elevation (bottom of pond), A a j,,,w 7,904 f'lz
'Depth' (distance b/w bottom of 1 Oft shelf and top of sediment) 8.50 ft
Average depth calculated it
Average depth used In SAIDA, d,v, (Round to nearest 0.5ft) ; ft
Drawdown Calculations
Drawdown through orifice? y ,' (Y or N)
Diameter of office (if circular) ^5.00' in
Area of orifice (if-non-droular) km2
Coefficient of discharge (Co) A.6Y (unitless)
Driving head (Hj 1.50! ft
Drawdown through weir? n "(Y or N)
Weir type (unittess)
Coefficient of discharge (C„) - (unitless)
Length of weir (L) ft
Driving head (H) ft
PreAevelopment 1-yr, 24-hr peak flow 11;84 felsec
Post development 1-yr, 24-hr peak flow 534felsec
Storage volume discharge rate (through discharge orifice or weir) 0,4B; fe/sec
Storage volume drawdown time 2.00; days OK draws down In 2-5 days.
Additional information
Vegetated side slopes 3 A OK
Vegetated shelf slope 10':1 OK
Vegetated shelf width 10.0 ft OK
Length of flowpath to width ratio 3 :1 OK
Length to width ratio 4T:1 OK
Trash rack for overflow & orifice? y s (Y or N) OK
Freeboard provided 1Q:0:ft OK
Vegetated filter provided? n (Y or N) OK
Recorded drainage easement provided? X (Y or N) OK
Capures all runoff at ultimate build-out? y (Y or N) OK
Drain mechanism for maintenance or emergencies is: 6 In[ m drawdpwn pipe with' gate vi66.
Form SW401-Wet Detention BasUrRev.8-9117109 Parts 1. & II. Design Sumn+ary, Page 2 &f2