SW3190701_Supplement EZ Form_20190927

SUPPLEMENT-EZ COVER PAGE
FORMS LOADED
PROJECT INFORMATION
1 Project Name Shop Addition- Harwood Automotive
2
Project Area aC
4.94
3
Coastal Wetland Area ac
0
4
Surface Water Area ac
0.17
5
Is this project High or Low Densi3 ?
High
6
1 Does this project use an off -site SCM?
No
COMPLIANCE WITH 02M.1003(4)
7
Width of vegetated setbacks provided feet
101+
8
Will the vegetated setback remain vegetated?
Yes
9
Is BUA other that as listed in .1003 4 ad out of the setback?
Yes
10
Is streambank stabilization proposed on this project?
No
NUMBER AND TYPE OF SCMS:
11
Infiltration Sy stem
0
12
t3ioretention Cell
0
13
Wet Pond
0
14
Slormwater Wetland
0
15
Permeable Pavement
0
16
Sand Filter
1
17
Rainwater Harvesting RWH
0
18
Green Roof
0
19
Level Spreader -Filter Strip LS-FS
0
20
Disconnected Impervious Surface (DIS)
0
21
Treatment Swale
0
22
Dry Pond
0
23
Stom liter
0
24
Silva Cell
0
25
Ha filter
0
26
Filterra
0
FORMS LOADED
DESIGNER CERTIFICATION
27
Name and THIe:
Mitchell Laatham P.E. President
28
Organization:
Latham -Walters Engineering, Inc.
29
Street address:
16507-A Northcross Drive
30
City,, State, Zip:
Huntersvilla NC 28078
31
Phone numbers ;
704-895-8484
32
Email:
[e-mail]
C—ediTilpatQn.Statemeft
I certify, under penalty of law that this Supplemort-FZ form and all supporting information were prepared under my direction or
supervision. that the information provided In the form is, to the best of my knowledge and belief, true, accurate, and complete: and that
the ergineering plans, specifications, operation and maintenance agreements and other supporting information are consistent with the
information provided here.
Ali
i
SEAL.
17'646
Gil
S.
Signature of Designer
use

DRAINAGE AREAS
1
Is this a high density project?
Yes
2
If so, number of drainage areas/SCMs
1
1 3
Is all/part of this project subject to previous rule
versions?
No
FORMS LOADED
DRAINAGE AREA INFORMATION
Entire Site
1
4
Type of SCM
Sand Filter
5
Total BUA in project (sq ft
47307 sf
16527 sf
6permitting)
New BUA on subdivided lots (subject to
s ft
7permitting)
New BUA outside of subdivided lots (subject to
sf
8868 sf
8868 sf
8
JOffsite - total area (sq ft
74874 sf
11305 sf
9
Offsite BUA (sq ft
0 sf
0 sf
10
Breakdown of new BUA outside subdivided lots:
Parking (sq ft
7267 sf
7267 sf
Sidewalk (sq ft
Roof (sq ft
1601 sf
1601 sf
Roadway s ft
Future (sq ft
Other, please specify in the comment box
below (sq ft
11
New infiltrating permeable pavement on
subdivided lots (sq ft
sf
12
New infiltrating permeable pavement outside of
Isubdivided lots (sq ft
13
Exisitng BUA that will remain (not subject to
ermittinq) (sq ft
38439 sf
7982 sf
14
Existing BUA that is already permitted (sq ft
0 sf
0 sf+
15
Existing BUA that will be removed (sq ft
16
Percent BUA
21.98%
32.28%
17
Design storm inches
1 in
18
IDesiqn volume of SCM cu ft
1092 cf
19
Calculation method for desi n volume
Simple
DDITIONAL INFORMATION
20
Please use this space to provide any additional information about the
drainage area(s):

DRAINAGE AREA INFORMATION
Entire Site
1
4
Type of SCM
N/A
Sand Filter
5
Total BUA from project (sq ft)
6
1995 rules
SL 2006-246
2008 rules
2017 rules
7
New BUA on subdivided lots (subject to
permitting) (sq ft)
1995 rules
SL 2006-246
2008 rules
2017 rules
New BUA outside of subdivided lots (subject
to permitting) (sf)
1995 rules
SL 2006-246
8
2008 rules
2017 rules
9
Offsite - total area (sq ft)
1995 rules
SL 2006-246
2008 rules
2017 rules
10
Offsite BUA (sq ft)
1995 rules
SL 2006-246
2008 rules
2017 rules
11
Design storm (inches)
1995 rules
SL 2006-246
2008 rules
2017 rules
12
Breakdown of new BUA:
Parking (sq ft
Sidewalk (sq ft
Roof (sq ft
Roadway s ft
Future (sq ft
Other, please specify in the comment box
below (sq ft
13
New infiltrating permeable pavement on
subdivided lots (sq ft
14
New infiltrating permeable pavement outside of
subdivided lots (sq ft
15permitting)
Exisitng BUA that will remain (not subject to
s ft
16
Existing BUA that is already permitted (sq ft
17
Existing BUA that will be removed (sq ft
18
Percent BUA
19
Desi n volume of SCM cu ft
20
Calculation method for design volume
ADDITIONAL
INFORMATION
21
Please use this space to provide any additional
information about the drainage area(s):

SAND FILTER
18
SHWT elevation (fmsl)
< 522.5
19
Type of sand filter (open or closed)
Open
20
If closed, will the filter will be pre -cast or pour -in -place?
21
If closed, top of grate elevation (fmsl)
22
Is this sand filter designed to attenuate peak flows?
Yes
Sediment Chamber
23
Volume that can be retained in the sediment chamber (cubic feet)
3045 cf
24
Will there be a permanent pool in the sediment chamber?
No
25
Bottom of the sediment chamber (fmsl)
526.00
26
Area of the sediment chamber (square feet)
742 sf
27
Physical depth of the sediment chamber (inches)
24"
28
Ponding depth in the sediment chamber, above any permanent pool
(inches)
24"
29
Elevation of top of weir between chambers (fmsl)
528
Sand Chamber
30
Volume that can be retained in the sand chamber (cubic feet)
Bottom of the sand chamber (fmsl)
1339 cf
31
523.50
32
Area of the sand chamber (square feet)
180 sf
33
Physical depth of the sand chamber (inches)
30"
34
Ponding depth in the sand chamber, above any permanent pool
(inches)
12"
35
Elevation of the bypass device (fmsl)
527
36
Type of bypass device
Weir
37
Mechanism for distributing flow over the sand surface
Rock Weir
38
Sand specification for sand chamber
ASTM C-33
39
Depth above underdrain pipe (inches)
18 in
Will the media be maintained to drain at least two inches per hour at
the sand surface?
Yes
L42O
Is at least one clean -out pipe provided at the low point of each
underdrain line?
Yes
Will clean -out pipes be capped?
Yes
Sand Filter 1 11:26 AM 9/27/2019