SW5230802_O&M Agreement/Plan_20230810

Operation & Maintenance Agreement
Project Name: Chatham Habitat for Humanity Townhouse Development
Project Location: Slier City, NC
Cover Page
Maintenance records shall be kept on the following SCM(s). This maintenance record shall be kept in a log in a known set location.
Any deficient SCM elements noted in the inspection will be corrected, repaired, or replaced immediately. These deficiencies can
affect the integrity of structures, safety of the public, and the pollutant removal efficiency of the SCM(s).
The SCM(s)on this project include(check all that apply&corresponding O&M sheets will be added automatically):
Infiltration Basin Quantity: 0 Location(s):
Infiltration Trench Quantity: 0 Location(s):
Bioretention Cell Quantity: 0 Location(s):
Wet Pond Quantity: 0 .__. Location(s):
Stormwater Wetland Quantity: 0 Location(s):
Permeable Pavement Quantity: 0 Location(s):
Sand Filter Quantity: 0 Location(s):
Rainwater Harvesting Quantity: 0 Location(s):
Green Roof Quantity: 0 Location(s):
Level Spreader-Filter Strip Quantity: 0 Location(s):
Proprietary System Quantity: 0 Location(s):
Treatment Swale Quantity:_ 0 Location(s): _
Dry Pond Quantity: 1 Location(s): Southwest portion of property
Disconnected Impervious Surface Present: No Location(s):
User Defined SCM Present: No Location(s):
Low Density Present: Yes Type:
CLICK TO UPDATE O&M MANUAL
I acknowledge and agree by my signature below that I am responsible for the performance of the maintenance procedures listed for
each SCM above, and attached O&M tables. I agree to notify NCDEQ of any problems with the system or prior to any changes to
the system or responsible party.
Responsible Party: Chatham Habitat for Humanity
Title& Organization: Mr. Harvey Harman, Director of Construction & Land Acquisition/Dev
Street address: 467 West St.
City, state, zip: Pittsboro, NC 27312
Phone number(s): 919-799-6819
Email: [e-mail]
e---)L
Signature: Date: s— / 2 d„2Sa
I, tA( rikW . .(AY- , a Notary Public for the State f tvQ l Q (i: tips
County of r r, a.w , do hereby certify that ct)/V 6 vVb lQ.vi
/� - l
personally appeared before me this 21-(' day of ��/ t 120ZS and
acknowledge the due execution o the and Maintena ce Ag iiiii .
t
Witness my hand and official seal, k1,1,1) i , , . �_4x_. . Fr� ` .
Avr
0
RODERICK W PARKER
Notary Public-North Carols .
Chatham County
My Commission Expires Nov 7, .1111.111111 6
h
Seal My commission expires \QO ,6/v o Z- 1
I
STORM-EZ 5/11/2023
Version 1.5 O&M Agreement Page 1 of 1

SUPPLEMENT-EZ COVER PAGE
LOAD SUPPLEMENT FORMS
JECT INFORMATION
1 Project Name Chatham Habitat for Humanity Townhouses
2 Project Area(ac) 3.12
3 Coastal Wetland Area(ac) 0
4 Surface Water Area(ac) 0
5 Is this project High or Low Density? Low
6 Does this project use an off-site SCM? No
7 Width of vegetated setbacks provided(feet) N/A
8 Will the vegetated setback remain vegetated? N/A
9 If BUA is proposed in the setback,does it meet NCAC 02H.1003(4)(c-d)? N/A
10 Is streambank stabilization proposed on this project? No
11 Infiltration System 0
12 Bioretention Cell 0
13 Wet Pond 0
14 Stormwater Wetland ll
15 Permeable Pavement 0
16 Sand Filter 0
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 1
23 StormFiiter 0
24 Silva Cell 0
25 Bayfiiter 0
26 Filterra 0
LOAD SUPPLEMENT FORMS
DESIGN,ER CERTIFICATION
27 Name and Title: Robert W.Brantly,P.E.-Consulting Engineer
28 Organization: Engineering&Environmental Science Co.
29 Street address: 3008 Anderson Dr.Ste.102
30 City,State,Zip: Raleigh,NC 27609
31 Phone number(s): 919-781-7798
32 Email: e2s@a bellsouth.net
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
011111/
\� 1/,
�N CAROB i,
•a SEAL < Signature of Designer
041984 : -
, �-frAKr •
NGIN���'•s�
Seal Date

DRAINAGE AREAS
1 Is this a high density project? _ No
2 If so,number of drainage areas/SCMs 0
3 Does this project have low density areas? Yes
4 If so,number of low density drainage areas 1
Is all/part of this project subject to previous rule
5 versions? No
FORMS LOADED
tbRAINAGE AREA INFORMATION '— Entire Site
4 Type of SCM Dry Detention
5 Total drainage area(sq ft) 465656
6 Onsite drainage area(sq ft) 135907
7 Offsite drainage area(sq ft) 329749 -
8 Total BUA in project(sq ft) 83401 sf
New BUA on subdivided lots(subject to permitting)
9 (sq ft) sf
New BUA not on subdivided lots(subject to
10 permitting)(sf) 76617 sf
11 Offsite BUA(sq ft) 7684 sf
12 Breakdown of new BUA not on subdivided lots:
-Parking(sq ft) 7062 sf
-Sidewalk(sq ft) 2465 sf
-Roof(sq ft) 12672 sf
-Roadway(sq ft) 6384 sf
-Future(sq ft) 48034 sf
-Other,please specify in the comment box
below(sq ft) sf
New infiltrating permeable pavement on
13 subdivided lots(sq ft) sf
New infiltrating permeable pavement not on
14 subdivided lots(sq ft) sf
Existing BUA that will remain(not subject to
15 permitting)(sq ft) 7684 sf
16 Existing BUA that is already permitted(sq ft) sf
17 Existing BUA that will be removed(sq ft) sf
18 Percent BUA 18%
19 Design storm(inches) 3.0 in
20 Design volume of SCM(cu ft) 25995 cf
21 Calculation method for design volume SCS
ADDITIONAL INFORMATION
Please use this space to provide any additional information about the
22 drainage area(s):

Permit No.
(to be provided by DWQ)
v4,47z:,VA= STORMWATER MANAGEMENT PERMIT APPLICATION FORM o .y
NCDENR 401 CERTIFICATION APPLICATION FORM
DRY EXTENDED DETENTION BASIN SUPPLEMENT
This form must be filled out,printed and submitted.
The Required Items Checklist(Part Ill)must be printed,filled out and submitted along with all the required information.
I. PROJECT INFORMATION
Project name Chatham Habitat for Humanity
Contact person Robert W.Brantly,P.E.(Consulting Engineer)
Phone number 919-781-7798
Date 5/11/2023
Drainage area number 1
II. DESIGN INFORMATION
Site Characteristics
Drainage area 465,656.00 ftz
Impervious area 81,022.00 ft2
%Impervious 0.17
Design rainfall depth 2.99 in
Peak Flow Calculations
1-yr,24-hr rainfall depth 2.99 in
Rational C,pre-development See Caclulations (unitless)
Rational C,post-development See Caclulations (unitless)
Rainfall intensity:1-yr,24-hr storm 0.12 in/hr
Pre-development 1-yr,24-hr peak flow 1.67 ft3/sec
Post-development 1-yr,24-hr peak flow 7.38 ft3/sec
Pre/Post 1-yr,24-hr peak control 5.71 ft3/sec
Storage Volume: Non-SA Waters
Minimum required volume 22,651.00 ft3
Provided volume 25,995.00 ft3 OK
Sediment storage volume provided 7,502.00 ft3 OK
Storage Volume: SA Waters
1.5"runoff volume ft3
Pre-development 1-yr,24-hr runoff volume ft3
Post-development 1-yr,24-hr runoff volume ft3
Minimum required volume ft3
Provided volume ft3
Sediment storage volume provided ft3
Basin Design Parameters
Drawdown time 2.30 days OK
SHWT elevation 609.00 fmsl
Basin bottom elevation 612.00 fmsl OK
Storage elevation 613.00 fmsl
Basin side slopes 3.0 :1 OK
Top elevation 617.00 fmsl OK
Freeboard provided 3.48 ft OK
Basin Bottom Dimensions
Basin length 124.00 ft
Basin width 56.00 ft
Length to width ratio 2.20 :1 OK
Form SW401-Dry Extended Detention Basin-Rev.3 Parts I.&II.Design Summary,Page 1 of 2

Permit No.
(to be provided by DWQ)
Additional Information
Total runoff volume captured by basin 3.30 ac-in Forebay is not required
Forebay provided N (Y or N)
Is basin in a recorded drainage easement? Y (Y or N) OK
Does basin capture all runoff at ultimate build-out? Y (Y or N) OK
Is a sediment depth indicator included? Y (Y or N) OK
Does the basin include a drain? Y (Y or N) OK
Form SW401-Dry Extended Detention Basin-Rev.3 Parts I.&II.Design Summary,Page 2 of 2