SW8050801_COMPLIANCE_20050803

STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO.
SW
DOC TYPE
❑ CURRENT PERMIT
❑ APPROVED PLANS
❑ HISTORICAL FILE
COMPLIANCE EVALUATION INSPECTION
DOC DATE
YYYYMMDD�

VORTECHS SYSTEM
Filename:
NET ANNUAL TSS REMOVAL EFFICIENCY
Project # SW8 050801
Date
Project Name Wilm.Intl.Airport Gen. Aviation Apron
Expai Reviewer
Recvng Stream Smith Creek
Classification
Drainage Basin Cape Fear
Index #
Site Area 3.2 acres
Drainage Area
Impervious Area Calculation
Buildings
Parking/Asphalt 151589
Concrete
Total, sq ft
Volume/Storage Calculation
S:\WPDATA\WQS\VORTECHS\050801
03-Aug-05
P.Bartlett
C; SW
18-74-63
151589 SF
3.48 ac
Rational Cc (list C after each BUA)
% Impervious- 100.0%
If Rational Method is used, place a 1 in this box 0
Cc:
1.00
RV
0.95
VORTECHS Model No. Selected 7000
Grit Chamber Area, sq ft 50.30
Design Ratio' M
Flow Rate Capacity, CIFS 11,0
10 Year 10 Min High Intensity Event
7.26 in/hr
RV
0.95
Volume Flow Rate
Required Bypass Capacity, 0
13.0 CFS
Elevation at B. ass Weir
Weir Elie v., ft:
24.8011-ength,
77il
L, ft:
CD1-
3.301
Rim Elev., ft:
Q=CDLH 3/2
H= 0.76
WEIR, WSEL:
Weir El, + H=F777T72s,.%Ift
Must be <
29.25 Rim Elev.
1", 30-Min Event
Volume Flow Rate
2.00 in/hr
Operating Rate
`.
902Jgpm/sf
Rainfall
Operating Rate2, 0/.Total Rainfall
%Removal
%Relative.
Intensity, in1hr
gpmisf Volume 3
Efflciencv4
Efficiency
0.02
0.59 4.40
98.0
4.3
0.04
1.18 4.80
98.0
4.7
0.06
1.77 5.20
98.0
5.1
0.08
2.36 4.60
97.0
4.5
0.10
2.95 4.00
97.0
3.9
0.12
3.54 3.50
95.8
3.4
0.14
4.13 3.70
94.1
3.5
0.16
4.72 3.50
94.1
3.3
0.18
5.31 3.20
92.6
3.0
0.20
5.90 3.20
92.6
3.0
0.25
7.38 6.20
90.0
5.6
0A5
13,28 18.40
80.3
14.8
0.65
19.18 10-70
70.9
7.6
0.85
25.08 6.80
63.0
4.3
1.00
29.51 6.10
58,2
3.6
1.25
36-89 3.30
503
1.7
1.50
44.27 3.80
41.1
1.6
1.75
51,64 1.70
32.1
0.5
2.00
59.02 1.00
22.1
0.2
2.25
66.40 0.70
17.0
0.1
2.50
73,78 0.80
12,9
0.1
78.5
% Rain Falling at >2.5in/hr or Bypassing Treatment
0A
Assumed Removal Efficiency for Bypassed Flows,
%
0.0
Removal Efficiency Adjustment , %
6.8
Net Annual TSS Removal Efficiency,
Required Net Annual TSS Removal Efficiency, % fC4,,
6 &_�4
Notes: V (,h 7 o ry
'Design Ratio= (Tot. Drain. Area) x (Runoff Coefficient) x (cfs to gpm conversion)/Grit Chamber Area
`Operating Rate, gpm/sf = Intensity, in/hr x Design Ratio v 1.: 0 0 -,7P)
'Based on 10 years of rainfall data from NCDC Station 9457, Wilmington WSO Airport, New Hanover County. NC
"Based on Vorlechnics laboratory verified removal of 50 micron particle gradation (Ref,: Technical Bulletin #11)
'Reduction due to use of 60-minute data for a site that has a time of concentration less than 30-minutes.