HomeMy WebLinkAboutSW3180905_O&M Agreement/Plan_20210712Operation & Maintenance Agreement
Project Name:
Project Location:
Twin Lakes
Union County, North Carolina
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 & cc
Infiltration Basin
Quantity:
Infiltration Trench
Quantity:
Bioretention Cell
Quantity:
Wet Pond
Quantity:
Stormwater Wetland
Quantity:
Permeable Pavement
Quantity:
Sand Filter
Quantity:
Rainwater Harvesting
Quantity:
Green Roof
Quantity:
Level Spreader - Filter Strip
Quantity:
Proprietary System
Quantity:
Treatment Swale ��Yassed S�1iAIQ�
Quantity:
Dry Pond
Quantity:
Disconnected Impervious Surface
Present:
User Defined SCM
Present:
Low Density
Present:
nding O&M sheets will
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):
Location(s):
Location(s):
Type:
ne aaaeo automaucaii
rner
m
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:
Title & Organization:
Street address:
City, state, zip:
Phone number(s),:
Dennis W. Moser, MAI
President - Twin Lakes Farm, LLC
231 Post Office Drive, Suite B8
Indian Trail, NC 28079
704-576-0022
Idmoser@themosergroupinc.com
Sign Cc Date:
I, e4i � e �--� �— , a Notary Public for the State of v ty
County of _61fA1,41c,/ , do hereby certify th �e�f) es Ztt - /;tc5&.,01
personally appeared before me this 1p — day of .�G�ly and ZO Z/
acknowledge the due execution of O erations and Maintenan Agreement.
Witness my hand and official seal ert,
RAENAE H
NOTARY F
Stanfy Q
North Ca
My commission Expi
Sea!
ITTLE
Aprl! 16, 2022
My commission expires !Z- L6_ 2,Z
STORM-EZ 7/2/2021
Version 1.5 O&M Agreement Page 1 of 9
Wet Pond Maintenance Requirements
important 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 greater
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.
5CM element:
Potential problem:
How to remediate the problem:
The entire wet pond
Trash/debris is present.
Remove the trash/debris.
The perimeter of the wet
Areas of bare soil and/or
Regrade the soil if necessary to remove the gully, plant ground
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
Unclog the pipe. Dispose of the sediment off -site.
applicable).
The inlet pipe is cracked
The inlet device
or otherwise damaged (if
Repair or replace the pipe.
applicable).
Erosion is occurring in the
Regrade the swale if necessary and provide erosion control
swale (if applicable).
devices such as reinforced turf matting or riprap to avoid 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.
The forebay
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.
SCM element
The main treatment area
The vegetated shelf
The embankment
The outlet device
Floating wetland island
(if applicable)
Wet Pond Maintenance Requirements (Continued)
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.
Algal growth covers over
Consult a professional to remove and control the algal growth.
50% of the area.
Cattails, phragmites or
Remove the plants by wiping them with pesticide (do not
other invasive plants cover
spray)'
50% of the basin surface.
Best professional
practices show that
pruning is needed to
Prune according to best professional practices.
maintain optimal plant
health.
Determine the source of the problem: soils, hydrology, disease
Plants are dead, diseased
etc. Remedy the problem and replace plants. Provide a one -
or dying.
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.
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.
A tree has started to grow
Consult a dam safety specialist to remove the tree.
on the embankment.
An annual inspection by
an appropriate
professional shows that
Make all needed repairs immediately.
the embankment needs
repair.
Clogging has occurred.
gg g
Clean out the outlet device and dispose of any sediment in a
location where it will not cause impacts to streams or the SCM.
The outlet device is
Repair or replace the outlet device.
damaged.
Weeds or volunteer trees
Remove the weeds or trees.
are growing on the mat.
The anchor cable is
damaged, disconnected or
Restore the anchor cable to its design state.
missing.
Wet Pond Maintenance Reauirements (Continued)
SCM 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.
Discharges from the wet
The receiving water
pond are causing erosion
Contact the local NCDEQ Regional Office.
or sedimentation in the
receiving water.
WET POND ID
1
Pretreatment other No
than forebay?
Has Veg. Filter? Yes
Wet Detention Pond Design Summary
Wet Pond Diagram
FOREBAY
Permanent Pool El.
628
Temporary Pool El:
629.62
Clean Out Depth:
6
Sediment Removal El
622
Bottom Elevation:
621
ATTACH ADDITIONAL SHEETS IF NECESSARY
MAIN POND
Permanent Pool El.
628
Temporary Pool El:
629.62
Clean Out Depth:
6
Sediment Removal El
622
Bottom Elevation:
621
Low Density Maintenance Requirements
Important 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 vegetated receiving area.
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 areas.
The vegetated conveyance or vegetated receiving area will be inspected quarterly. Records of operation and
maintenance will be kept in a known set location and will be available upon request.
Inspection activities shall be performed as follows. Any problems that are found shall be repaired immediately.
5CM element:
Potential problem:
How to remediate the problem:
Vegetation is too short or
Maintain grassed vegetation such that the swale or vegetated
Vegetation
too long.
area does not erode during the peak flow from the 10-year
storm
Trash/debris is present.
Remove the trash/debris.
Areas of bare soil and/or
Regrade the soil if necessary to remove the gully, and then re -
Vegetated receiving
erosive gullies have
sod (or plant with other appropriate species) and water until
formed.
established. Provide lime and a one-time fertilizer application.
areas
Trees and/or other woody
Remove the trees and woody vegetation from the swale,
vegetation are present in
regrade the swale if necessary and re-establish grass as shown
the swale.
on the approved plans.
Trash/debris is present.
Remove the trash/debris.
Areas of bare soil and/or
Regrade the soil if necessary to remove the gully, and then re -
erosive gullies have
sod (or plant with other appropriate species) and water until
formed.
established. Provide lime and a one-time fertilizer application.
Sediment covers the grass
Remove sediment and dispose in an area that will not impact
Vegetated conveyances /
at the bottom of the swale.
streams or SCMs. Re -sod if necessary.
swales I roadside
ditches (other than curb
The side slope is steeper
Regrade the slopes to the permitted configuration per the
outlet swales)
than the approved
approved plan and reestablish vegetation. If as -built or existing
configuration.
conditions do not allow the slopes to be regraded, contact the
applicable permitting agency.
Determine the source of the problem: soils, hydrology, disease:
Grass is dead, diseased or
etc. Remedy the problem and replace plants. Provide a one -
dying.
time fertilizer application to establish the ground cover if
necessary.
Trees and/or other woody
Remove the trees and woody vegetation from the vegetated
vegetation are present in
conveyance, regrade the vegetated conveyance if necessary
the vegetated
and re-establish grass as shown on the approved plans.
,conveyance.
The longitudinal slope Regrade to meet the permitted longitudinal slope as shown on
exceeds 5%. the approved plans.
Curb outlet swales or The swale profile does not Regrade the swale to the approved profile as shown on the
vegetated areas match the approved detail. approved plans.
The length of the swale or Extend the swale to achieve the 100-foot minimum length. If as
vegetated area is less built or existing conditions do not allow the slopes to be
than 100 feet. regraded, contact the applicable permitting agency.
Clogging has occurred.
Clean out the outlet device. Dispose of the sediment off -site.
The outlet device (if
applicable)
The outlet device is
damaged
Repair or replace the outlet device.
Erosion or other signs of
damage have occurred at
Repair the damage and improve the flow dissipation structure.
the outlet.
Discharges from the site
The receiving water
are causing erosion or
sedimentation in the
Contact the local NCDEQ Regional Office.
receiving water.
Treatment Swale Maintenance Requirements
Important operation and maintenance procedures:
The drainage area of the grassed swale will be carefully managed to reduce the sediment load to the
grassed swale.
After the initial fertilization to establish the grass in the swale, fertilizer will not be applied to the
treatment swale.
The grassed swale will be inspected quarterly. 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.
5CM element:
Potential problem:
How to remediate the problem:
Trash/debris is present.
Remove the trash/debris.
Areas of bare soil and/or
Regrade the soil if necessary to remove the gully, re -sod (or
erosive gullies have
plant with other appropriate species) and water until
formed.
established. Provide lime and a one-time fertilizer application.
Sediment covers the grass
Remove sediment and dispose in an area that will not impact
at the bottom of the swale.
streams or SCMs. Re -sod if necessary.
The entire length of the
swale
Vegetation is too short or
too long.
Maintain grassed vegetation such that the swale or vegetated
area does not erode during the peak flow from the 10-year
storm
Determine the source of the problem: soils, hydrology, disease
Grass is dead, diseased or
etc. Remedy the problem and replace plants. Provide a one -
dying.
time fertilizer application to establish the ground cover if
necessary.
Trees and/or other woody
Remove the trees and woody vegetation from the treatment
vegetation are present in
swale, regrade the treatment swale if necessary and re -
the treatment swale.
establish grass as shown on the approved plans.
Clogging has occurred.
Clean out the outlet device. Dispose of the sediment off -site.
The outlet device (if
The outlet device is
damaged
Repair or replace the outlet device.
applicable)
Erosion or other signs of
damage have occurred at
Repair the damage and improve the flow dissipation structure.
the outlet.
The receiving water
Discharges from the
treatment swale are
causing erosion or
Contact the local NCDEQ Regional Office.
sedimentation in the
receiving water.