SW6240402_Supplement-EZ Form_20240405

SUPPLEMENT-EZ COVER PAGE
FORMS LOADED
PROJECT INFORMATION
1 Project Name Blackburn Farm-Phase 2
2 Project Area(ac) 25.59�•�-....._�..�.
3 Coastal Wetland Area(ac) -
4 Surface Water Area(ac) 0
5 Is this project High or Low Density? High
6 Does this project use an off-site SCM? No
COMPLIANCE WITH 02H.1003(4)::
7 Width of vegetated setbacks provided(feet) 30
8 Will the vegetated setback remain vegetated? Yes
9 If BUA is proposed in the setback,does it meet NCAC 02H.1003(4)(c-d)? No ____. ..
10 Is streambank stabilization proposed on this project? i No
NUMBER AND TYPE OF SCMs:
11 Infiltration System 0
12 Bioretention Cell 2
13 Wet Pond 0
14 Stormwater Wetland 0
15 Permeable Pavement 0
16 ISand Filter 0
17 Rainwater Harvesting(RWH) 0
18 Green Roof 0
19 Level Spreader-Fitter Strip(LS-FS) ! 0_.__
20 Disconnected Impervious Surface(DlS) 0
21 Treatment Swale O__._.._._..____.__._________..___,
22 Dry Pond ._.O_.
•
23 Storm Filter 0
24 Silva Cell 0
Bayfilte
r �__._..._..__..._._....._... ___.__._0
26 0
FORMS LOADED
:DESIGNER CERTIFICATION
27 Name and Title: Carlo Pardo,PE •
28 Organization: I Bowman North Carolina,Ltd.
29 Street address: 4006 Barrett Drive,Suite 104
30 City,State,Zip: ` Raleigh,NC 27609
31 Phone number(s): 919-553-6570
32 [Email: j [e-mail]
Certification Statement
I certify,under penalty of law that this Supplement=EZ 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 engineering plans
specifications,operation and maintenance agreements and other supporting information are consistent with the information provided here. ..
Designer
\`\\‘\lllllltiJl//iy//,
,RL ...04/1/i CAA
•
Q �� ' = Signature of Designer
SEAL
051571
••
- -e •
Dale

DRAINAGE AREAS
1 Is this a high density project? 1 Yes
2 If so,number of drainage areas/SCMs 2
3 Does this project have low density areas? No
4 If so,number of low density drainage areas E 0 _
Is all/part of this project subject to previous rule
5 versions? No
FORMS LOADED
DRAINAGE AREA INFORMATION Entire Site
ma Type of SCM m� - BioRetention BioRetention
5 (Total drainage area(sq ft) 1114771 sf 522218 105338
6 )Offsite drainage area(sq ft) 1114771 sf 1 512091 105338
7 Offsite drainage area(sq ft) 9127 i
IIER Total BUA in project sq ft) 269586 sf I 227412 sf ._ 42174 sf
ElNew BUA on subdivided lots(subject to permitting), —�
(sq ft) 192000 sf 168000 sf 24000 sf
New BUA not on subdivided lots(subject to 6 )
i
10 permitting)(sf) 77586 sf 59412 sf i 18174 sf f
11 Offsite BUA(sq ft) 1265 sf
ingBreakdown of new BUA not on subdivided lots:
MI -Parking(sq ft)
Sidewalk(sq ft) 19636 sf 14847 sf 4789 sf
Roof(sq ft) ._..
Mil -Roadway(sq ft) 57950 sf 43300 sf 13385 sf
-Future(sq ft j
-Other,please specify in the comment box
below(sq ft) !
New infiltrating permeable pavement on
13 subdivided lots(sq f() I,in _ I 1
New infiltrating permeable pavement not on
subdivided lots(sq ft) I
1111 Existing BUA that will remain(not subject toI .
•
permitting)(sq ft)
16 Existing BUA that is already permitted(sq ft)
iffli Existing BUA that will be removed . ft —18 Percent BUA 24.18% 43.5% 40.0%
19 Design storm(inches) 1.0 in F 1.0 in
20 Design volume of SCM(cu ft) 19232 cf 3602 cf
21 Calculation method for design v.ume W-- —Simple Meth
_Simple Method_t
ADDITIONAL INFORMATION
Please use this space to provide any additional information about the :,
22 drainage area(s): .
9

BIORETENTION CELL
1 Drainage area number 1 i 2
2 Minimum required treatment volume(cu ft)
19232 cf 3602 cf
GENERAL MDC FROM 02H.1050
3 Is the SCM sized to treat the SW from all surfaces at build-out? I Yes Yes
4 Is the SCM located away from contaminated soils? I Yes Yes
5 What are the side slopes of the SCM(H:V)? 3:1 3:1
Does the SCM have retaining walls,gabion walls or other engineered
6 side slopes? No No
Are the inlets,outlets,and receiving stream protected from erosion
7 (10-year storm)? Yes Yes
Is there an overflow or bypass for inflow volume in excess of the I
8 design volume? Yes Yes
What is the method for dewateringthe SCM for maintenance? _._.
9 Pump(preferred) Pump(preferred)
10 If applicable,will the SCM be cleaned out after construction? Yes Yes
11 Does the maintenance access comply with General MDC(8)? Yes Yes
12 Does the drainage easement comply with General MDC(9)? Yes Yes
If the SCM is on a single family lot,does(will?)the plat comply with
13 General MDC(10)? N/A N/A
14 Is there an O&M Agreement that complies with General MDC(11)? Yes Yes
15 Is there an O&M Plan that complies with General MDC(12)? Yes Yes
16 Does the SCM follow the device specific MDC? Yes Yes
Was Me SCM designed byan NC licensed professional?17 g p Yes Yes
,BIORETENTION CELL MDC FROM 02H.1052
18 SHWT elevation(fmsl)- 146.00 ' - 147.00
—19 Bottom of the bioretention cell(fmsl) 152.30 153.00
20 Ponding depth of the design storm(inches) 12 in 12 in
21 Surface area of the bioretention cell(square feet) 21795 sf 4275 sf
~22 Design volume of SCM(cu ft) 22703 cf 4790 cf
23 Is the bioretention cell used for peak attenuation? Yes Yes
24 Depth of peak attenuation over planting surface(in) 30 in 23 in
25 Height of peak attenuation outlet above the planting surface(in) 18 in 18 in
26 Infiltration rate of the in situ soil(inch/hour) 2 in/hr 2 in/hr
_27 Diameter of the underdrain pipes(if applicable) 6 in 6 in
28 Does the design include Internal Water Storage(IWS)? Yes — Yes
29 if so,elevation of the top of the IWS(fmsl) 150.8 151.5
30 Elevation of the planting surface(fmsl) 152.30 153
31 'other)? Grass Grass
32 Media depth(inches) _I 30 in 30 in
33 Percentage of medium to coarse washed sand by volume 75-85% 75-85%
34 Percentage of fines(silt and clay)by volume 8-10% 8-10%
35 Percentage of organic matter by volume 5-10% 5-10%
36 Type of organic material ' Pine Bark Fines Pine Bark Fines
37 Phosphorus Index(P-Index)of media(unitless) 30 30
38 ,Will compaction be avoided during construction? Yes Yes
39 Will cell be maintained to a one inch/hour standard? Yes Yes
40 Depth of mulch,if applicable(inches)
41 Type of mulch,if applicable
pipes
42 �How manyclean out i es are beinginstalled? 24 5�
43 Y epee o etreatmenTthat will be used: I-ip-Rap/Forebay Rip-Flap/I-orebay-
ADDITIONAL INFORMATION
Please use this space to provide any additional information about the
44 bioretention cell(s):
Bioretention 1 4:29 PM 2/15/2024