26_Guildford-Mackintosh SCM 1_O&M Agreement

Burlington Wet Detention Basin O&M Agreement- July 2013

WET DETETION BASIN
OPERATION AND MAINTENANCE AGREEMENT

Project Name: Guilford Mackintosh Marina Wet Detention Pond #1__ ____
City Project Number: ___________________
City BMP ID: Guilford Mackintosh BMP #1 ___________________
PIN Number: 8833372823-000 ___ ________________
Mail after recording to: City of Burlington
Stormwater Division
P.O. Box 1358
Burlington, NC 27216

NORTH CAROLINA

ALAMANCE COUNTY

This STORMWATER OPERATION AND MAINTENANCE AGREEMENT,
made this day _18th ___ of ___February____, 20 __15___
by _____City of Burlington – Stormwater Division ______ whose principal address is
______1103 S. Mebane Street, Burlington NC 27216__________with, to, and for the benefit of
the City of Burlington, a municipal corporation of the State of North Carolina, whose address is
P.O. Box 1358, Burlington, North Carolina 27216.
Burlington Wet Detention Basin O&M Agreement- July 2013 Page 2 of 5
Wet Detention Basin Operation and Maintenance Agreement

I will keep a maintenance record on this BMP. This maintenance record will be kept in a log in a
known set location. 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 removal efficiency of the BMP.

The wet detention basin system is defined as the wet detention basin, pretreatment
including forebays and the vegetated filter if one is provided.

This system (check one):
does X does not incorporate a vegetated filter at the outlet.

This system (check one):
does X does not incorporate pretreatment other than a forebay.

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. Records of operation and maintenance
should be kept in a known set location and must be available upon request.
Annually, by May 31, an inspection shall be completed by a qualified professional and
submitted to the City of Burlington.

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 wet
detention basin
Areas of bare soil and/or erosive
gullies have formed.
Regrade the soil if necessary to remove
the gully, and then plant a ground cover
and water until it is established.
Provide lime and a one-time fertilizer
application.
Vegetation is too short or too
long.
Maintain vegetation at a height of
approximately six inches.

Burlington Wet Detention Basin O&M Agreement- July 2013 Page 3 of 5
BMP element: Potential problem: How I will remediate the problem:
The inlet device: pipe or
swale
The pipe is clogged. Unclog the pipe. Dispose of the
sediment off-site.
The pipe is cracked or otherwise
damaged.
Replace the pipe.
Erosion is occurring in the
swale.
Regrade the swale if necessary to
smooth it over and provide erosion
control devices such as reinforced turf
matting or riprap to avoid future
problems with erosion.
The forebay Sediment has accumulated to a
depth greater than the original
design depth for sediment
storage.
Search for the source of the sediment
and remedy the problem if possible.
Remove the sediment and dispose of it
in a location where it will not cause
impacts to streams or the BMP.
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 herbicide is used, wipe it on the
plants rather than spraying.
The vegetated shelf Best professional practices show
that pruning is needed to
maintain optimal plant health.
Prune according to best professional
practices
Plants are dead, diseased or
dying.
Determine the source of the problem:
soils, hydrology, disease, etc. 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 herbicide is used, wipe it on the
plants rather than spraying.
The main treatment area Sediment has accumulated to a
depth greater than the original
design sediment storage depth.
Search for the source of the sediment
and remedy the problem if possible.
Remove the sediment and dispose of it
in a location where it will not cause
impacts to streams or the BMP.
Algal growth covers over 50%
of the area.
Consult a professional to remove and
control the algal growth.
Cattails, phragmites or other
invasive plants cover 10% of the
basin surface.
Remove the plants by wiping them with
herbicide (do not spray).

Burlington Wet Detention Basin O&M Agreement- July 2013 Page 4 of 5
BMP element: Potential problem: How I will remediate the problem:
The embankment Shrubs have started to grow on
the embankment.
Remove shrubs immediately.
Evidence of muskrat or beaver
activity is present.
Use traps to remove muskrats and
consult a professional to remove
beavers.
A tree has started to grow on the
embankment.
Consult a dam safety specialist to
remove the tree.
An annual inspection by
appropriate professional shows
that the embankment needs
repair. (if applicable)
Make all needed repairs.
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 damage
have occurred at the outlet.
Contact the City of Burlington Water
Resources Stormwater Division
at 336-222-5140.

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.

When the permanent pool depth reads 561 feet in the main pond, the sediment shall be
removed.

When the permanent pool depth reads 561 feet in the forebay, the sediment shall be
removed.

BASIN DIAGRAM
(fill in the blanks)
Permanent Pool Elevation 565

Sediment Removal El. 561 Permanent Pool
Volume Sediment Removal Elevation 561 Volume
Bottom Elevation 560 1-ft Min.
Sediment Bottom Elevation 560 1-ft Min.
Storage Sediment Storage FOREBAY MAIN POND

Burlington Wet Detention Basin O&M Agreement- July 2013 Page 5 of 5
I acknowledge and agree by my signature below that I am responsible for the
performance of the maintenance procedures listed above. I agree to notify the City of
Burlington of any problems with the system or prior to any changes to the system or
responsible party.

Project name: Guilford Mackintosh Marina Wet Detention Pond #1
BMP drainage area number: Area #1

Print name: Michael Layne PE
Title: Water Resources - Field Operations Manager
Address: 1103 S. Mebane Street, Burlington NC 27216
Phone: [phone]
Signature:
Date:

I, _____________________________________, a Notary Public for the State of
____________________, County of ____________________, do hereby certify that
______________________________________ personally appeared before me
this day of _________________, _______, and acknowledge the due
execution of the forgoing wet detention basin maintenance requirements. Witness my
hand and official seal,

SEAL

My commission expires