20090105 Ver 1_More Info Received_20090213

Searstone - response to request for additional information
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Subject: Searstone - response to request for additional information @Eg -1'3 2009
From: "Diaz, Jennifer" <[e-mail]>
Date: Fri, 13 Feb 2009 11:10:33 -0500 Wamohm
To: "Joseph Gyamfi" <[e-mail]>
CC: <[e-mail]>, "Caldwell, James" <[e-mail]>
Hi Joseph,
Per our phone conversation yesterday, attached pleased find the documents in response to your request for
additional information. The water quality volume for Pond #1 was routed as a 1-inch storm in PonclPack. The
output is provided for you attached. Also, the supplement forms have been updated as requested. The
bypass channel section has been updated with the principal spillway pipe description. I have also provide the
principal spillway riprap details that were not included in the pond detail set you received, but were included
in the construction drawing set approved by the Town of Cary. If you should have any further concerns,
please do not hesitate to ask.
-Jennifer
Jennifer Diaz, PE
Project Engineer
Office: 919-287-4262
,A:,dd to address book
EcolEngineering
A division ol" I`hA Jahn R. McAdams ('ornpany, Inc.
P.O. Box 14005, Research Triangle Park, NC 27709
Design Services Focused On Client Success
Please consider the environment before you print this e-mail.
Content-Description: SEARSTONE - updated
supplement forms.pdf
SEARSTONE -updated supplement forms.pdf Content-Type: application/octet-stream
Content-Encoding: base64
SEARSTONE - bypass pipe riprap details.pdf
SEARSTONE
Content-Description: - bypass
pipe riprap details.pdf
Content-Type: application/octet-stream
Content-Encoding: base64
SEARSTONE - Pond #1 WQ volume.pdf' Content-Description: SEARSTONE - Pond #1 WQ
volume.pdf
1 of 2 2/13/2009 11:18 AM
Searstone - response to request for additional information
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2 of 2 2/13/2009 11:18 AM
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838.80 ENDWALL
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36" 0-RING RCP
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NCDOT STD.
838.80 END
(SEE SHEET
SW-4C)
NOTE;
A FILTER BLANKET IS TO BE INSTALLED
BETWEEN THE RIPRAP AND SOIL FOUNDATION.
THE FILTER BLANKET WILL CONSIST OF A
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#57) UNDERLAIN WITH MIRAFI FILTER WEAVE 700
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Type.... Master Network Summary Page 2.01
Name.... Watershed
FI.Io.... X:\Projects\SRF\SRF-05000\Storm\Construct.ion Drawings\PortdPack\SRFO5000-1-INCH.PPW
MASTER DESIGN STORM SUMMARY
Network Storm Collection: RDU Rainfall
Total.
Depth Rainfall
Return Event in T ype RNF ID
------------ ------ ---------------- ----------------
1 inch 1.0000 Synthetic Curve TypeII 24hr
ICPM CALCULATION TOLERANCES
Target Convergence= .000 cfs +/_
Max. Iterations = 35 loops
ICPM Time Step - 1.00 min
Output Time Step = 1.00 min
ICPM Ending Time -=
-------------------- 1440.00
-------- ruin
---
MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversi.on;)
(Trun= l1YG Truncation: Blank=None; L Left; R=Rt; LR=LefL&Rt)
Return HYG Vol
Node ID
----------------- Type
---- Event
------ ac-ft Trun
-----------
POND #I-LOWER POND 0 1.138
POND #1-LOWEROUT POND 0 1.116
POND Ill-UPPER POND 0 .256
POND 01-UPPEROUT POND 0 .254
"SUBBASIN #1 JCT 0 1.116
TO POND 01.-LOWER AREA 0 .886
TO UPPER POND #1 AREA 0 .257
Qpeak
min
716.00
725.00
715.00
724.00
725.00
715.00
715.00
Max
Qpeak Max WSEL Pond Storage
cfs
- ft
------
- ar.-ft
--
-------
-----
--
17.74 - --
-
7.32 361.74 .323
4.03
1.50 370.02 .074
7.32
16.66
4.03
/N: 621701207003 The John R. McAdams Company
Pond Pack Ver. 8.0058 Time: 9:16 AM Date: 2/13/2009
SEARSTONE, WATER QUALITY VOLUME DESIGN SHEET J.C. Diaz, P1
SRI=-05000 fond #1 LS 2/13/2009
1. CALCULATION OF Dian REQUIRED IN SPLITTER SOX FOR I" STORM
Q = 7.32 cfs from Pondpack Output
Size of orifice = 15 inches
Area of orifice (A) - 1.227 sq ft
Apply orifice equation ==> Q = C„A4(2gh)
Assume CI) 0.6
Driving head on orifice (h) = 1.53 ft the difference between the principal
spillway pipe invert and orifice centroid
elevation
Invert of principal spillway pipe bypass = 339.80
Orifice- centroid elevation = 338.27
Minimum invert of orifice= 337.64
Therefore, set invert to level spreader elevation = 337.60
and invert of bypass to elevation = 339.80
U. DETERMINE REQUIRED LEVEL SPREADER LENGTH
Q = 7.32 cfs front PondPack Output
Using 13' per I cfs, level spreader length - 95.16 feet
Therefore, level spreader required for V event = 96 feet
RR&ROWRCRI p
FEB 13 2009
MNR • WATER QUMM
YYETIANDS AND STORMINKER BRANCH
1in runoff Pond #1 LS
NCDENR
P
?bux> Y,
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
LEVEL SPREADER, FILTER STRIP AND RESTORED RIPARIAN BUFFER SUPPLEMENT
This form must be completely fitted out, printed and submitted.
DO'r:i' FCARGET TO ATTACH THE REQUIRED ITFMS CHECKLIST AND ALL REQUIRED ITEMS (NEXT WORKSHEET)!
(,'PROJECT INFORMATION _
Project name Searstone
Contact name James W. Caldwell, PE
Phone number 919.361.5000
Date October 22, 2008

Drainage area number _
To Pond #1
Ill, DESIGN INFORMATION
For Level Spreaders Receiving Flow From a BMP
Type of BMP Wet Pond
Drawdown flow from the BMP 7.32 cfs
For Level Spreaders Receiving Flow from the Drainage Area
Drainage area N/A ftz
Impervious surface area NIA fl2
Percent impervious #VALUE! °k
Rational C coefficient NIA
Peak flow from the 1 in/hr storm #VALUE! cis
Time of concentration NIA min
Rainfall intensity, 10-yr storm N/A in/hr
Peak flow from the 10-yr storm #VALUE! cis to r
Where Does the Level Spreader Discharge?
To a grassed bioretention cell? N (Y or N)
To a mulched bioretention cell? N (Y or N)
To a wetland? _ N (Y or N)
To a filter strip or riparian buffer? Y (Y or N) F ,u co } o o> s1
Other (specify)
Filter Strip or Riparian Buffer Characterization (if applicable)
Width of grass 0.00 ft
Width of dense ground cover 123.00 ft
Width of wooded vegetation 0.00 ft
Total width 123.00 fl
Elevation at downslope base of level lip 336.75 fmsl
Elevation at top of bank of the receiving water 330.00 fmsi
Slope (from level lip to to top of bank) 5.49 %
Are any draws present? N (Y or N) ;•h
Level Spreader Design
Forebay surface area NIA sq ft r aUet.
Feet of level lip needed per cis 13 fticfs
Answer `Y" to one of the following:
Length based on the 1 in/hr storm? N (Y or N)
Length based on the 10-yr storm? N (Y or N)
Length based on the BMP discharge rate? Y_ (Y or N)
Design flow 7.32 cis
Is a bypass device provided? Y ? (Y or N) r.
Form SW401-Level Spreader, Filter Strip, Restored Riparian Buffer-Rev.5 Paris I. and II. Design Summary, page 1 of 2
Length of the level lip
Are level spreaders in series?
Bypass Channel Design (if applicable)
Does the bypass discharge through a wetland?
Does the channel enter the stream at an angle?
Dimensions of the channel (see diagram below):
M
B
W
y
Peak velocity in the channel during the 10-yr storm
Channel lining material
t
M
96.00 It
N (Y or N)
N (Y or N)
Y (Y or N)
N/A ft
NIA It
N/A It
NIA ft
22.65 fps cfs
42' dia. o-ring pipe
y 1
----------
M

1 B

Form SW401-Level Spreader, Fitter Strip, Restored Riparian Buffer-Rev.5 Parts I. and II. Design Summary, page 2 of 2
NCDENR

STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
LEVEL SPREADER, FILTER STRIP AND RESTORED RIPARIAN BUFFER SUPPLEMENT
This form must be completely filled out, printed and submitted.
DO NOT FORGET TO ATTACH THE REQUIRED ITEMS CHECKLIST AND ALL REQUIRED ITEMS (NEXT WORKSHEET)l
L PROJECT INFORMATION
Project name Searstone
Contact name James W. Caldwell, PE
Phone number 919.361.5000
Date October 22, 2008
Drainage area number To Dry Detention Basin #2
IL DESIGN INFORMATION
For Level Spreaders Receiving Flow From a BMP
Type of BMP Dry Detention Basin _
Drawdown flow from the BMP 0.92 cfs
For Level Spreaders Receiving Flow from the Drainage Area
Drainage area
Impervious surface area
Percent impervious
Rational C coefficient
Peak flow from the 1 in/hr storm
Time of concentration
Rainfall intensity, 1 0-yr storm
Peak flow from the 10-yr storm
Where Does the Level Spreader Discharge ?
To a grassed bioretention cell?
To a mulched bioretention cell?
To a wetland?
To a filter strip or riparian buffer?
Other (specify)
Filter Strip or Riparian Buffer Characterization (if applicable)
Width of grass
Width of dense ground cover
Width of wooded vegetation
Total width
Elevation at downslope base of level lip
Elevation at top of bank of the receiving water
Slope (from level lip to to top of bank)
Are any draws present?
Level Spreader Design
Forebay surface area
Feet of level lip needed per cis
Answer "Y" to one of the following:
Length based on the 1 in/hr storm?
Length based on the 10-yr storm?
Length based on the BMP discharge rate?
Design flow
Is a bypass device provided?

ft2 D"TIN phis of lh .,
ft' i).a uol ; Il,,
% Or)rir,i <,; rl a, a "f II,•
0:J nal rs:??n?lul:-: llli. ;n ,,i lh, a
cis , r ,, ..r? -1,5w "I
min
in/hr nul roc Jill,, -"
,. -
-fi a r,t I_
cfs (101 , n,i, rWll ;;, :i„1
N (Y or N)
N ?(YorN)
N (Y or N)
Y (Y or N) orn,a+ ?r, rdrer sir, r h d? gyn. below
0.00 ft
155.00 ft
0.00 ft
155.00 It
335.50 fmsi
330.00 flnsl
3.55 %
N (Y or N) c,l<

NIA sq ft No 010,=1?,i fs n,:ulJca.
13 fUcfs
N
N
Y
0.92
Y
(Y or N)
(Y or N)
(Y or N)
cfs
(Y or N)
Form SW401-Level Spreader, Fitter Strip, Restored Riparian Buffer-Rev.5 Parts r, and tl. Design Summary, page 1 of 2
Length of the level lip 13.00 ft
Are level spreaders in series? N (Y or N)
Bypass Channel Design (if applicable)
Does the bypass discharge through a wetland? N (Y or N)
Does the channel enter the stream at an angle? Y (Y or N)
Dimensions of the channel (see diagram below)
M NIA It
B NIA ft
W NIA ft
y NIA ft
Peak velocity in the channel during the 10-yr storm 4.47 fps cfs
Channel lining material 36" dia. o-ring pipe
y
M
1 e l
I
M
KV4'? JFJ
t
Form SW401-level Spreader, Filter Strip, Restored Riparian Buffer-Rev 5 Parts I. and II, Design Summary, page 2 of 2
NCDENR

STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
LEVEL SPREADER, FILTER STRIP AND RESTORED RIPARIAN BUFFER SUPPLEMENT
This form must be completely filled out, printed and submitted.
DO NO F FORGE°I` ll 0 ATTACI°I THE REQUIRED ITEMS CHECKLIST AND ALL REQUIRED ITEMS (NEXT WORKSHEET)!
LiPItOJECT INFORMATION
Project name Searstone
Contact name James W. Caldwell, PE
Phone number 919.3615000
Date October 22, 2008
Drainage area number To Dry Detention Basin #3
Ill, DESIGN INFORMATION
For Level Spreaders Receiving Flow From a BMP
Type of BMP Dry Detention Basin
Drawdown flow from the BMP 1.32 cfs
For Level Spreaders Receiving Flow from the Drainage Area
Drainage area _ fe
Impervious surface area ft2
Percent impervious %
Rational C coefficient
Peak flow from the 1 in/hr storm cfs
Time of concentration min
Rainfall intensity, 10-yr storm in/hr
Peak flow from the 10-yr storm cfs
Where Does the Level Spreader Discharge ?
112.00 it
0.00 ft
112.00 ft
323.50 fmsl
320.00 fmsl
3.13 ^%
N (Y or N)
NIA sq ft
13 ft/cfs
To a grassed bioretention cell? N (Y or N)
To a mulched bioretention cell? N (Y or N)
To a wetland? N (Y or N)
To a filter strip or riparian buffer? Y (Y or N)
Other (specify)
Filter Strip or Riparian Buffer Characterization (if applicable)
Width of grass
Width of dense ground cover
Width of wooded vegetation
Total width
Elevation at downslope base of level lip
Elevation at top of bank of the receiving water
Slope (from level lip to to top of bank)
Are any draws present?
Level Spreader Design
Forebay surface area
Feet of level lip needed per cfs
Answer °Y® to one of the following:
Length based on the 1 inlhr storm?
Length based on the 10-yr storm?
Length based on the BMP discharge rate?
Design flow
Is a bypass device provided?
0.00
Ian rO (',)u :" ni
Do w
nut Corr:
Go not (' N,, rig+',I
L1o ??t,t
'K
OK
t1•u IoMl 'y is fwu , J.
N (Y or N)
N (Y or N)
Y (Y or N)
1.32 cis
Y (Y or N) crK
Form SW401-Level Spreader, Filter Strip, Restored Riparian Buffer-Rev.5 Parts I. and II. Design Summary, page 1 of 2
Length of the level lip
Are level spreaders in series?
Bypass Channel Design (if applicable)
Does the bypass discharge through a wetland?
Does the channel enter the stream at an angle?
Dimensions of the channel (see diagram below):
M
B
W
Y
Peak velocity in the channel during the 10-yr storm
Channel lining material

M
18.00 ft
N (Y or N)
N (Y or N)
Y (Y or N)
NIA ft
NIA ft
N/A ft
N/A ft
8.82 fps cfs
36" dia. o-ring pipe
Y

.t
M

Form SW401-Level Spreader, Filter Strip, Restored Riparian Buffer•Rev.5 Parts I. and 11. Design Summary, page 2 of 2
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fit
NCDENR a' Y
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
LEVEL SPREADER, FILTER STRIP AND RESTORED RIPARIAN BUFFER SUPPLEMENT
This form must be completely filled out, printed and submitted.
DO NOT FORGET TO ATTACH THE REQUIRED ITEMS CHECKLIST AND ALL REQUIRED ITEMS (NEXT WORKSNf"ET)t
(.'PROJECT INFORMATION 4.?
Project name Searstone
Contact name James W. Caldwell, PE
Phone number 919.361.5000
Date October 22, 2008
Drainage area number To Dry Detention Basin #4
Ih' DESIGN INFORMATION -- - -`
For Level Spreaders Receiving Flow From a BMP
Type of BMP Dry Detention Basin
Drawdown flow from the BMP 1.14 cis
For Level Spreaders Receiving Flow from the Drainage Area
Drainage area it,
Impervious surface area fe t?c• ,
Percent impervious % ,
Rational C coefficient -? WWV k0 not
Peak flow from the 1 in/hr storm cfs ,
Time of concentration min
Rainfall intensity, 10-yr storm in/hr Po I
Peak flow from the 10-yr storm cis «?
Where Does the Level Spreader Discharge?
To a grassed bioretention cell? N (Y or N)
To a mulched bioretention cell? N (Y or N)
To a wetland? N (Y or N)
To a filter strip or riparian buffer? Y (Y or N) I'i s
Other (specify)
Filter Strip or Riparian Buffer Characterization (if applicable)
Width of grass
Width of dense ground cover
Width of wooded vegetation
Total width
Elevation at downslope base of level lip
Elevation at top of bank of the receiving water
Slope (from level lip to to top of bank)
Are any draws present?
Level Spreader Design
Forebay surface area
Feet of level lip needed per cis
Answer "Y" to one of the following:
Length based on the 1 in/hr storm?
Length based on the 10-yr storm?
Length based on the BMP discharge rate?
Design flow
Is a bypass device provided?
0.00 it
124.00 it
0.00 it
124.00 it
319.50 fmsl
316.00 fmsl
2.82 % OK
N (Y or N) ,'K

NIA sq it ?: i r is n. ?rvd.
13 fticfs
N (Y or N)
N (Y or N)
Y (Y or N)
1.14 cfs
_
(Y or N) cap:
Form SW401-Level Spreader, Filter Strip, Restored Riparian Buffer-Rev.5 Parts I. and il. Design Summary, page 1 of 2
Length of the level lip 15.00 ft
Are level spreaders in series? N (Y or N)
Bypass Channel Design (if applicable)
Does the bypass discharge through a wetland? N (Y or N)
Does the channel enter the stream at an angle? Y (Y or N)
Dimensions of the channel (see diagram below):
M N/A ft
B N/A ft
W N/A It
y N/A ft
Peale velocity in the channel during the 10-yr storm 5.68 fps efs
Channel lining material 36" dia. o-rin g pipe
M
1
1 '
Y
M
I
1 B 1
I t
M
4VAl li;..
w
Form SW401-1_evel Spreader, Fitter Strip, Restored Riparian Buffer-Rev.5 Parts I. and II. Design Summary, page 2 of 2