SW6170802 - Coldstream at Thrower (2)

e� Operation A Maintenance Agreement
_ F
Project Name
Project Location:
Coldstream at Thrower
Thrower Road, Hope Mills, NC
Maintenance records shall be kept on the following BMP(s) This maintenance record shall be kept in a log in a known set locatio
Any deficient BMP 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 BMP(s).
The BMP(s) on this project include (check all that apply & cc
Bioretention Cell Quantity
Dry Detention Basin
Grassed Swale
Green Roof
Infiltration Basin
Infiltration Trench
Level SpreaderNFS
Permeable Pavement
Proprietary System
Rainwater Harvesting
Sand Filter
Stormwater Wetland
Wet Detention Basin
Disconnected Impervious Area
User Defined BMP
Quantity:
Quantity.
Quantity.
Quantity
Quantity
Quantity
Quantity
Quantity
Quantity*
Quantity.
Quantity:
Quantity:
Present:
Present:
ig O&M tables will be added automatically):
Location(s)
Location(s)
Location(s)
Location(s)
Location(s)
Location(s)
Location(s):
Location(s):
Location(s):
Location(s):
Location(s),
Location(s)
Location(s) North side of prop, near Thrower Road
Location(s)
Location(s)-
I acknowledge and agree by my signature below that I am responsible for the performance of the maintenance procedures listed for
each BMP above, and attached O&M tables I agree to notify NCDENR of any problems with the system or prior to any changes to
the system or responsible party
* Responsible Party
Title & Organization
Street address,
City, state, zip
Phone number(s).
Email
Signature
John D. Hornaday
Managing Member, Coldstream Developers, LLC
581 Executive Place, Suite 700
Fayetteville, NC 28305
910-483-9715
[e-mail]
Date %
I, A Thl a Notary Public for the State of
County ofdo hearby certify that IV
personally appeared before me this day of calla , 71 and '
acknowledge the due execution of the Operations and Maintenance Agreement
Witness my hand and official seal,
Version 1 4
O&M Manual
7/19/2017
Page 1 of 5

f Wet -Detention Pond Maintenance Requirements !
The wet detention basin system is defined as the wet detention basin, pretreatment including forebays and the vegetated filter if
one is provided.
Important maintenance procedures.
Immediately after the wet detention basin is established, the plants on the vegetated shelf and perimeter of the
basin should be watered twice weekly if needed, until the plants become established (commonly six weeks).
No portion of the wet detention pond should be fertilized after the first initial fertilization that is required to
establish the plants on the vegetated shelf
Stable groundcover should be maintained in the drainage area to reduce the sediment load to the wet detention
basin.
If the basin must be drained for an emergency or to perform maintenance, the flushing of sediment through the
emergency drain should be minimized to the maximum extent practical.
- Once a year, a dam safety expert should inspect the embankment
After the wet detention pond is established, it should be inspected once a month and within 24 hours after every storm event
greater than 1.0 inches (or 1.5 inches if in a Coastal County). Records of operation and maintenance should be kept in a
known set location and must be available upon request
Inspection activities shall be performed as follows Any problems that are found shall be repaired immediately
BMP element:
Potential problem:
How I will remediate the problem:
The entire BMP
Trash/debris is present
Remove the trash/debris
The perimeter of the BMP
Areas of bare soil and/or
Regrade the soil if necessary to remove the gully, and then plant a
erosive gullies have formed.
ground cover and water until it is established Provide lime and a one-
time fertilizer application
Vegetation is too short or too
Maintain vegetation at a height of approximately six inches
long.
The inlet device
The pipe is clogged
Unclog the pipe. Dispose of the sediment off-site.
The pipe is cracked or
Replace the pipe.
otherwise damaged
Erosion is occurring in the
Regrade the swale if necessary to smooth it over and provide erosion
swale.
control devices such as reinforced turf matting or riprap to avoid future
problems with erosion
Stone verge is clogged or
Remove sediment and replace with clean stone
covered in sediment (if
applicable).
The forebay
Sediment has accumulated to
Search for the source of the sediment and remedy the problem if
a depth greater than the
possible Remove the sediment and dispose of it in a location where it
original design depth for
will not cause impacts to streams or the BMP.
sediment storage
Erosion has occurred
Provide additional erosion protection such as reinforced turf matting or
riprap if needed to prevent future erosion problems.
Weeds are present.
Remove the weeds, preferably by hand If pesticide is used, wipe it on
the plants rather than spraying.
The vegetated shelf
Best professional practices
Prune according to best professional practices
show that pruning is needed
to maintain optimal plant
health
Plants are dead, diseased or
Determine the source of the problem soils, hydrology, disease, etc
dying
Remedy the problem and replace plants. Provide a one-time fertilizer
application to establish the ground cover if a soil test indicates it is
necessary
Weeds are present
Remove the weeds, preferably by hand If pesticide is used, wipe it on
the plants rather than spraying
STORM -EZ 7/19/2017
Version 1 4 O&M Manual Page 3 of 5

Wet Detention Pond Maintenance Requirements (Continued) i
The main treatment area
Sediment has accumulated to
Search for the source of the sediment and remedy the problem if
a depth greater than the
possible Remove the sediment and dispose of it in a location where it
original design sediment
will not cause impacts to streams or the BMP.
storage depth.
Algal growth covers over 50%
Consult a professional to remove and control the algal growth
of the area.
Cattails, phragmites or other
Remove the plants by wiping them with pesticide (do not spray)
invasive plants cover 50% of
the basin surface.
The embankment
Shrubs have started to grow
Remove shrubs immediately
on the embankment.
Evidence of muskrat or
Use traps to remove muskrats and consult a professional to remove
beaver activity is present
beavers.
A tree has started to grow on
Consult a dam safety specialist to remove the tree.
the embankment
An annual inspection by an
Make all needed repairs.
appropriate professional
shows that the embankment
needs repair. (if applicable)
The outlet device
Clogging has occurred
Clean out the outlet device Dispose of the sediment off-site
The outlet device is damaged
Repair or replace the outlet device.
The receiving water
Erosion or other signs of
Contact the local NC Department of Environment and Natural
damage have occurred at the
Resources Regional Office
outlet.
The measuring device used to determine the sediment elevation shall be such that it will give an accurate depth reading and not
readily penetrate into accumulated sediments
STORM -EZ 7/19/2017
Version 1 4 O&M Manual Page 4 of 5

Wet Detention Pond Design Summary
Wet Pond Diagram
WET POND ID FOREBAY MAIN POND
BMP -1 Permanent Pool EI 148 Permanent Pool EI. 148
Temporary Pool EI 1489 Temporary Pool EI 1489
Pretreatment other No Clean Out Depth 4 Clean Out Depth 4
than forebay? Sediment Removal EI 144 Sediment Removal EI 144
Has Veg Filter? No Bottom Elevation. 143 Bottom Elevation 143
STORM -EZ 7/19/2017
Version 1 4 O&M Manual Page 5 of 5

SUPPLEMENT -EZ FORM COVER PAGE
Please indicate the types, quantities and locations of SCMs that will be used on this project:
Quantity Location(s)
Infiltration System
Bioretention Cell
Wet Pond 1 North side of property near Thrower Road
Stormwater Wetland
Permeable Pavement
Sand Filter
Rainwater Harvesting
Green Roof
Level Spreader -Filter Strip
Disconnected Impervious Surface
Treatment Swale
Dry Pond
Designer information for this project:
Name and Title
JJeffrey A Nobles, PE
Organization
Larry King & Associates, RLS, PA
Street address
1333 Morganton Road, Suite 201
City, State, Zip-
Fayetteville, NC 28305
Phone number(s)
910-483-4300
Email:
([e-mail]
Designer
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Sign r o igner
Date
Applicant:
Project Name:
Coldstream at Thrower
Address
2789 Thrower Road
City / Town
Hope Mills
Company
Coldstream Developers, LLC
Contact:
Pnvf7ann�✓a
Mailing Address
1581 Executive Place, Suite 700
Project Name:
Coldstream at Thrower
Address
2789 Thrower Road
City / Town
Hope Mills
Company
Coldstream Developers, LLC
Contact:
JJohn D Hornaday
Mailing Address
1581 Executive Place, Suite 700
City, State, Zip
Fayetteville, NC 28305
Phone number(s)
910-483-9715
Email
hornadaycc@aol com
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
I am aware that there are significant penalties for submitting false
information including the possibility of fines and imprisonment for knowing
violations as well as a report being made to my professional board
Cover Page 1 116 PM 7/19/2017

WETPOND
Coldstream at Thrower
THE DRAINAGE AREA
Design volume of SCM (cu ft)
Drainage area number
1
Break down of BUA in the drainage area (both new and existing):
Yes
Total coastal wetlands area (sq ft)
sf
Parking / driveway (sq ft)
Yes
Total surface water area (sq ft)
sf
Sidewalk (sq ft)
Yes
Total drainage area (sq ft)
2477195 sf
Roof (sq ft)
BUA associated with existing development (sq ft)
sf
Roadway (sq ft)
I 206070 sf
Proposed new BUA (sq ft)
622070 sf
Other, please specify in the comment box below (sq ft)
416000 sf
Percent BUA of drainage area
25%
Total BUA (sq ft)
622070 sf
COMPLIANCE WITH THE APPLICABLE STORMWATER PROGRAM
Stormwater program(s) that apply (please specify)Design
SADA
rainfall depth (in)
1.0 in
Phase II
66779 sf
Mirnmum volume required (cu ft)
1 56977 cf
Wet Pond 1 117 PM 7/19/2017
Design volume of SCM (cu ft)
GENERAL MDC FROM 02H.1050
#1 Is the SCM sized to treat the SW from all surfaces at build -outs
Yes
#7 If applicable, with the SCM be cleaned out after construction?
Yes
#2 Is the SCM located on or near contaminated soils?
No
#8 Does the mainetenance access comply with General MDC (8)?
Yes
#3 What are the side slopes of the SCM (H V)?
3-1
#9 Does the drainage easement comply with General MDC (9)v
Yes
#3 Does the SCM have retaining walls, gabion walls or other engineered side slopes'?
No
#10 If the SCM is on a single family lot, does the plat comply with General MDC (10)?
#4 Are the inlets, outlets, and receiving stream protected from erosion (10 -year storm)?
Yes
#11 Is there an O&M Agreement that complies with General MDC (11)?
Yes
#5 Is there a a bypass for flows in excess of the design flow9
No
Is there an O&M Plan that complies with General MDC (12)?
Yes
#6 What is the method for dewatenng the SCM for maintenances
Pump (preferred)#13
J#12
Was the SCM designed by an NC licensed professional?
Yes
WET POND MDC FROM 02H .1053
#1 Method used
SADA
#6 Width of the vegetated shelf (feet)
10 ft '
#1 Surface area of the main permanent pool (square feet)
66779 sf
#6 Location of vegetated shelf
@ Normal Pool
#1 Volume of the main permanent pool (cubic feet)
241194 cf
#6 Elevation of top of shelf (fmsl)
; 149 ft
#2 Average depth of the main pool (feet)
4 ft
#6 Elevation of bottom of shelf (fmsl)
I 148 ft
#2 Was the vegetated shelf included in the calculation of average depth?
Yes
#6 Slope of vegetated shelf (H V)
10,1
#2 Elevation of the bottom of the permanent pool (fmsl)
143 ft
#7 Diameter of drawdown orifice (inches)
6,0 in
#2 Elevation of the top of the permanent pool (fmsl)
148 ft
#7 Drawdown time for the temporary pool (hours)
52 hrs
#2 Elevation of the top of the temporary pool (fmsl)
149 ft
#7 Does the onfice drawdown from below the top surface of the permanent pool?
Yes
#3 Depth provided for sediment storage (inches)
12 in
#8 Does the pond minimize impacts to the receiving channel from the 1 -yr, 24 -hr stormy
I Yes
#4 Are the inlet(s) and outlet located in a manner that avoids short-circuiting?
Yes
#9 Are fountains proposed?
No
#4 Describe any measures, such as berms or baffles, that will be taken to improve the flow path#9
If yes, is documentation provided per Wet Pond MDC (9)?
m #10 Is a trash rack or other device provided to protect the outlet system?
Yes
#5 Volume of the forebay (cubic feet)
48,574
#11 Are the dam and embankment planted in non -clumping turf grass?
#5 Is this 15-20% of the volume in the main pool?
Yes
#11 Species of turf that will be used on the dam and embankment
€ centipede
#5 Depth of forebay at entrance (inches)
60 in
#11 Describe the planting plan for the vegetated shelf
_
#5 Depth of forebay at exit (inches)
#5 Does water flow out of the forebay in a non-erosive manner?
#5 Clean-out depth for forebay (inches)
#5 Will the forebay be cleaned out when the depth is reduced to less than the above'?
60in
Yes
12 in
Yes
Shallow Land Community. 1 plant/ 4sf = 1421 plants
Water Community. 1 plant / 4 sf =1382 plants
n
Shallow
ADDITIONAL INFORMATION
Please use this space to provide any additional information about this wet pond that you think is relevant to the review
"Other" BUA area calculated as 4000 sf ! residential lot ` 104 lots = 416,000sf
Wet Pond 1 117 PM 7/19/2017