SW6230705_O&M Agreement/Plan_20230831

Project Name: Serenity Ph 3-5
Project Location: Harnett County, NC
Cover Page
aintenance records shall be kept on the following SCM(s). This maintenance record shall be kept in a log in a known set location.
iy deficient SCM elements noted in the inspection will be corrected, repaired, or replaced immediately. These deficiencies can
fect the integrity of structures, safety of the public, and the pollutant removal efficiency of the SCM(s).
ie SCM(s) on this project include (check all that apply&corres•onding O&M sheets will be added automatically):
Infiltration Basin Quantity:_ Location(s):
Infiltration Trench Quantity:- Location(s):
Bioretention Cell Quantity: Location(s):
Wet Pond Quantity: 5 Location(s): 3-west side of site; 1-south end; 1-middle
Stormwater Wetland Quantity:- Location(s):
Permeable Pavement Quantity:- Location(s):
Sand Filter Quantity:- Location(s):
Rainwater Harvesting Quantity:- Location(s):
Green Roof Quantity:- Location(s):
Level Spreader- Filter Strip Quantity:- Location(s):
Proprietary System Quantity:- Location(s):
Treatment Swale Quantity:_ Location(s):
Dry Pond Quantity:_ Location(s):
Disconnected Impervious Surface Present: No Location(s):
User Defined SCM Present: No Location(s):
Low Density Present: Yes Type: Curb outlet system
acknowledge and agree by my signature below that I am responsible for the performance of the maintenance procedures listed for
ach SCM above, and attached O&M tables. I agree to notify NCDEQ of any problems with the system or prior to any changes to
e system or responsible party.
Responsible Party: Yang Song
Title& Organization: Manager-Greenfield Serenity Investco, LLC
Street address: 8601 Six Forks Road, Suite 270
City, state, zip: Raeligh, NC 27615
Phone number(s): 919-551-5888
Email: [e-mail]
Signature: Date: 06/10 / 3
\ 1(4- e . O, e.4,1 , a Notary Public for the State of NMao GaR.QI�N�l
Runty of w Nee. , do hereby certify that \IPOJCG ,S©OGI
:rsonally appeared before me this 2.1Y'41 day of �w►J a"0 a3 and
:knowledge the due execution of the Operations and Maintenance Agreement .
fitness my hand and official seal,41;41141
_
KRISTLE H. OSTEEN
NOTARY PUBLIC
WAKE COUNTY, N.C.
sal My commission expires 7L44..)� `� 'Xj71
ORM-EZ 6/6/2(

nportant operation and 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 pond should be fertilized after the initial fertilization that is required to
establish the plants on the vegetated shelf.
Stable groundcover will be maintained in the drainage area to reduce the sediment load to the wet
pond.
If the pond must be drained for an emergency or to perform maintenance, the flushing of sediment
through the emergency drain will be minimized as much as possible.
At least once annually, a dam safety expert will inspect the embankment. Any problems that are
found will be repaired immediately.
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.
After the wet pond is established, it will be inspected quarterly and within 24 hours after every storm event
Treater than 1.0 inches (or 1.5 inches if in a Coastal County) . Records of operation and maintenance shall be
kept in a known set location and shall be available upon request.
Inspection activities shall be performed as follows. Any problems that are found shall be repaired immediately.
CM element: Potential problem: How to remediate the problem:
he entire wet pond Trash/debris is present. Remove the trash/debris.
he perimeter of the Areas of bare soil and/or Regrade the soil if necessary to remove the gully, plant ground
et pond erosive gullies have cover and water until it is established. Provide lime and a one-
formed. time fertilizer application.
The inlet pipe is clogged
(if applicable). Unclog the pipe. Dispose of the sediment off-site.
The inlet pipe is cracked
or otherwise damaged (if Repair or replace the pipe.
he inlet device applicable).
Regrade the swale if necessary and provide erosion control
Erosion is occurring in the devices such as reinforced turf matting or riprap to avoid
swale (if applicable). future problems with erosion.
Sediment has
accumulated to a depth Search for the source of the sediment and remedy the problem
greater than the original if possible. Remove the sediment and dispose of it in a
design depth for sediment location where it will not cause impacts to streams or the SCM.
storage.
he forebay
Erosion has occurred.
Provide additional erosion protection such as reinforced turf
matting or riprap if needed to prevent future erosion problems.
Remove the weeds, preferably by hand. If pesticide is used,
Weeds are present. wipe it on the plants rather than spraying.

CM element: Potential problem: How to remediate the problem:
Sediment has
accumulated to a depth Search for the source of the sediment and remedy the problem
greater than the original if possible. Remove the sediment and dispose of it in a
design sediment storage location where it will not cause impacts to streams or the SCM.
depth.
he main treatment
rea Algal growth covers over Consult a professional to remove and control the algal growth.
50% of the area. g
Cattails, phragmites or
other invasive plants Remove the plants by wiping them with pesticide (do not
cover 50% of the basin spray).
surface.
Best professional
practices show that
pruning is needed to Prune according to best professional practices.
maintain optimal plant
health.
he vegetated shelf Determine the source of the problem: soils, hydrology,
Plants are dead, diseased disease, etc. Remedy the problem and replace plants. Provide
or dying. a one-time fertilizer application to establish the ground cover if
a soil test indicates it is necessary.
Remove the weeds, preferably by hand. If pesticide is used,
Weeds are present. wipe it on the plants rather than spraying.
Shrubs have started to Remove shrubs immediately.
grow on the embankment.
Evidence of muskrat or Consult a professional to remove muskrats or beavers and
beaver activity is present. repair any holes or erosion.
he embankment A tree has started to
grow on the embankment. Consult a dam safety specialist to remove the tree.
An annual inspection by
an appropriate
professional shows that Make all needed repairs immediately.
the embankment needs
repair.
Clogging has occurred. Clean out the outlet device and dispose of any sediment in a
gg g location where it will not cause impacts to streams or the SCM.
he outlet device
The outlet device is
damaged. Repair or replace the outlet device.
Weeds or volunteer trees
are growing on the mat. Remove the weeds or trees.
boating wetland island
F applicable) The anchor cable is
damaged, disconnected Restore the anchor cable to its design state.
or missing.

CM element: Potential problem: How to remediate the problem:
Erosion or other signs of
damage have occurred at Repair the damage and improve the flow dissipation structure.
the outlet.
he receiving water Discharges from the wet
pond are causing erosion
or sedimentation in the Contact the local NCDEQ Regional Office.
receiving water.

Wet Pond Diagram
WET POND ID FOREBAY MAIN POND
SCM 12 Permanent Pool El. 312.5 Permanent Pool El. 312.5
Temporary Pool El: 313.98 Temporary Pool El: 313.98
Pretreatment No Clean Out Depth: 4.5 Clean Out Depth: 5.5
other than Sediment Removal E 308 Sediment Removal E 307
Has Veg. Filter? No Bottom Elevation: 306.5 Bottom Elevation: 306.5
I
WET POND ID FOREBAY MAIN POND
SCM 13 Permanent Pool El. 307.5 Permanent Pool El. 307.5
Temporary Pool El: 309.42 Temporary Pool El: 309.42
Pretreatment No Clean Out Depth: 4.5 Clean Out Depth: 5.5
other than Sediment Removal E 303 Sediment Removal E 302
Has Veg. Filter? Yes Bottom Elevation: 301.5 Bottom Elevation: 301.5
WET POND ID FOREBAY MAIN POND
SCM 14 Permanent Pool El. 303 Permanent Pool El. 303
Temporary Pool El: 304.75 Temporary Pool El: 304.75
Pretreatment No Clean Out Depth: 4.12 Clean Out Depth: 5
other than Sediment Removal E 298.88 Sediment Removal E 298
Has Veg. Filter? Yes Bottom Elevation: 297.5 Bottom Elevation: 297.5
WET POND ID FOREBAY MAIN POND
SCM 15 Permanent Pool El. 295.5 Permanent Pool El. 295.5
Temporary Pool El: 296.82 Temporary Pool El: 296.82
Pretreatment No Clean Out Depth: 3.75 Clean Out Depth: 4.5
other than Sediment Removal E 291.75 Sediment Removal E 291
Has Veg. Filter? Yes Bottom Elevation: 290.5 Bottom Elevation: 290.5
WET POND ID FOREBAY MAIN POND
SCM 16 Permanent Pool El. 279.5 Permanent Pool El. 279.5
Temporary Pool El: 281.01 Temporary Pool El: 281.01
Pretreatment No Clean Out Depth: 4.5 Clean Out Depth: 5.5
other than Sediment Removal E 275 Sediment Removal E 274
Has Veg. Filter? Yes Bottom Elevation: 273.5 Bottom Elevation: 273.5
ATTACH ADDITIONAL SHEETS IF NECESSARY

1portant maintenance procedures:
The drainage area to the vegetated conveyance or vegetated receiving area will be
carefully managed to reduce the sediment load to the vegetated conveyance or
After the initial fertilization to establish the grass in the vegetated conveyance or the
vegetated receiving area, fertilizer will not be applied to the vegetated receiving
le vegetated conveyance or vegetated receiving area will be inspected quarterly. Records of
)eration and maintenance will be kept in a known set location and will be available upon request.
:ion activities shall be performed as follows.Any problems that are found shall be repaired immediately.
CM element: Potential problem: How to remediate the problem:
Vegetation is too short Maintain grassed vegetation such that the swale or
egetation vegetated area does not erode during the peak flow
or too long. from the 10-year storm
I iaaiuuCuna lb Remove the trash/debris.
nrnr.nn+
Areas of bare soil
Regrade the soil if necessary to remove the gully, and
and/or erosive gullies
then re-sod (or plant with other appropriate species)
egetated receiving have formed. and water until established. Provide lime and a one-
*eas time fertilizer application.
Trees and/or other Remove the trees and woody vegetation from the
woody vegetation are swale, regrade the swale if necessary and re-establish
present in the swale. grass as shown on the approved plans.
Trash/debris is
Remove the trash/debris.
present.
Areas of bare soil Regrade the soil if necessary to remove the gully, and
and/or erosive gullies
then re-sod (or plant with other appropriate species)
have formed. and water until established. Provide lime and a one-
time fertilizer application.
Sediment covers the
grass at the bottom of Remove sediment and dispose in an area that will not
egetated impact streams or SCMs. Re-sod if necessary.
)nveyances/ the swale.
wales/roadside The side slope is Regrade the slopes to the permitted configuration per
itches (other than steeper than the the approved plan and reestablish vegetation. If as-
.irb outlet swales) approved built or existing conditions do not allow the slopes to
configuration. be regraded, contact the applicable permitting
Determine the source of the problem: soils,
Grass is dead, hydrology, disease, etc. Remedy the problem and
diseased or dying. replace plants. Provide a one-time fertilizer
application to establish the ground cover if necessary.
Trees and/or other Remove the trees and woody vegetation from the
woody vegetation are vegetated conveyance, regrade the vegetated
present in the conveyance if necessary and re-establish grass as
vegetated shown on the approved plans.

The longitudinal Regrade to meet the permitted longitudinal slope as
slope exceeds 5%. shown on the approved plans.
The swale profile does
urb outlet swales or not match the Regrade the swale to the approved profile as shown
?getated areas on the approved plans.
approved detail.
IIIC !GI iy LII UI LIIC CXLCIIU U1C JVVdIC LU dC.IIICVC LIIC IUU-IUUL If IIIIIIIIUIII
swale or vegetated length. If as-built or existing conditions do not allow
area is less than 100 the slopes to be regraded, contact the applicable
fraof norm Minn anon ...xi

Clogging has Clean out the outlet device. Dispose of the sediment
occurred. off-site.
he outlet device(if
,plicable)
The outlet device is
damaged Repair or replace the outlet device.
Erosion or other signs
of damage have Repair the damage and improve the flow dissipation
occurred at the outlet. structure.
he receiving water Discharges from the
site are causing
erosion or Contact the local NCDEQ Regional Office.
sedimentation in the
receiving water.