SW6130203_Supplement-EZ Form_20240423 (2)

INFILTRATION SYSTEM
1 Drainage area number 1
2 Minimum re wired treatment volume cu ft
25444 cf
GENERAL MDC FROM 02H.1050
3 'Is the SCM sized to treat the SW from all surfaces at build-out? i Yes
4 Is the SCM located away from contaminated soils? Yes
5 What are the side slopes of the SCM(H:V or enter"Vertical"for
trenches)? 3:1
6 Does the SCM have retaining walls,gabion walls or other engineered
side sloes? No
7 lAre the inlets,outlets. and receiving stream protected from erosion
(10-year storm)? Yes
8 Is there an overflow or bypass for inflow volume in excess of the
design volume? Yes
9 What is the method for dewatering the SCM for maintenance? Pump(preferred)
10 If applicable,will the SCM be cleaned out after construction? Yes
11 Does the maintenance access comply with General MDC(8)•
? Yes
12 Does the drainage easement comply with General MDC(9)? Yes
13 'If the SCM is on a single family lot,does(will?)the plat comply with
General MDC 10? N/A
14 Is there an O&M Agreement that complies with General MDC(11)? Yes
15 11s there an O&M Plan that complies with General MDC(12)? Yes
16 Does the SCM follow the device specific MDC? Yes
17 Was the SCM designed by an NC licensed professional? Yes
INFILTRATION SYSTEM MDC FROM 02H.1051
18 Proposed slope of the subgrade surface(%) 0%
19 Are terraces or baffles provided? No
20 Type of pretreatment: Forebay
(Soils Data
21 Was the soil investigated in the footprint and at the elevation of the
infiltration system? Yes
22 SHWT elevation(fmsl) <414
23 Depth to SHWT per soils report(in) < 124
24 Ground elevation at boring in soils report(fmsl) 424.30
25 Is a detailed hydrogeologic study attached if the separation is
between 1 and 2 feet? N/A
.
26 Soil infiltration rate(in/hr) 0.91
27 'Factor of safety(FS) (2 is recommended): 2.00
Elevations
29 Bottom elevation(fmsl) 420.00
30 Storage elevation(fmsl) _ 422.ft
31 Bypass elevation(fmsl) 422 ft
For Basins Only
32 Bottom surface area(ft2) _ 11373 ft
33 Storage elevation surface area(ft2) 14102.ft
For Trenches Only
34 Len th(ft)
35 'Width(ft)
36 Perforated pipe diameter,if applicable(inches)
37 Number of laterals
38 Total len th of perforated piping
39 Stone type,if applicable
_40 Stone porosity(%)
41 Is stone free of fines?
42 Is the stone wrapped in geotextile fabric?
43 Has at least one inspection port been provided?
I Volumes/Drawdown
44 Design volume of SCM(cu ft) 25444 cf
45 Time to draw down(hours) 72 hrs
ADDITIONAL INFORMATION
46 Please use this space to provide any additional information about the
infiltration system(s):
Infiltration 1 1:13 PM 4/23/2024