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Municipal Separate Storm Sewer Operation and Maintenance Plan
Draft
Description
This plan serves as guide for maintaining the operation of post constructed Stormwater
Control Measures (SCMs) on sites that are required to meet stormwater controls as determined
by Section 14 of the City of Gastonia's MuniCode. All designs for SCMs are to follow the latest
NC Stormwater Design Manual as provided by NC Department of Environmental Quality. The
As -Built documents provided once construction of the SCMs are complete should also contain
the Operation and Maintenance of plan for any and all SCMs (and best management practices)
associated with maintaining the Stormwater Control Measures.
Inspection Procedure and Authority
Site inspections should be conducted regularly throughout the year to ensure that SCM
is functioning during various climatic occurrences. Outcome reports should be provided to the
manager or owner of each SCM and should be held on site to ensure the integrity of the SCM is
maintained. 3rd party reports are encouraged, as a good faith effort by the site manager, but
official inspections are to be performed by staff who have received certification through NC
State Universities SCM Maintenance and Inspection program and are in good standing. The
following forms provided by NCSU are to be used as the the appropriate method to inspect and
manage the SCMs on each site.
Additional Considerations
When performing inspections, it is also pertinent to examine the inlets, outlets and
drainage area to the SCMs. To ensure that the most effective maintenance is being considered,
it is also important to ensure that no additional contributions of impacts are accelerating the
maintenance frequency, there by impairing the overall function of the SCM.
SCM Inspection & Maintenance Forms
Table of Contents
Bioretention Inspection and Maintenance Agreement................................................................. Page 1
Dry Extended Detention Basin Inspection and Maintenance Agreement .................................. Page 5
Filter Strip, Restored Riparian Buffer and Level Spreader I & M Agreement ............................. Page 9
Permeable Pavement Inspection and Maintenance Agreement ................................................. Page 12
Sand Filter Inspection and Maintenance Agreement.................................................................... Page 15
Stormwater Wetland Inspection and Maintenance Agreement ................................................. Page 18
Wet Detention Basin Inspection and Maintenance Agreement .................................................. Page 22
These forms are available on-line at: https://deg.nc.gov/about/divisions/energy-mineral-land-resources/
energy-mineral-land-permit-guidance/stormwater-bmp-manual/forms
Permit Number:
(to be provided by DWQ)
Drainage Area Number:
Bioretention 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.
Important operation and maintenance procedures:
— Immediately after the bioretention cell is established, the plants will be watered
twice weekly if needed until the plants become established (commonly six
weeks).
— Snow, mulch or any other material will NEVER be piled on the surface of the
bioretention cell.
— Heavy equipment will NEVER be driven over the bioretention cell.
— Special care will be taken to prevent sediment from entering the bioretention cell.
— Once a year, a soil test of the soil media will be conducted.
After the bioretention cell is established, I will inspect it 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 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.
BMP element:
Potentialproblems:
How I will remediate theproblem:
The entire BMP
Trash/debris is present.
Remove the trash/debris.
The perimeter of the
Areas of bare soil and/or
Regrade the soil if necessary to
bioretention cell
erosive gullies have formed.
remove the gully, and then plant a
ground cover and water until it is
established. Provide lime and a
one-time fertilizer application.
The inlet device: pipe,
The pipe is clogged (if
Unclog the pipe. Dispose of the
stone verge or swale
applicable).
sediment off -site.
The pipe is cracked or
Replace the pipe.
otherwise damaged (if
applicable).
Erosion is occurring in the
Regrade the swale if necessary to
swale (if applicable).
smooth it over and provide erosion
control devices such as reinforced
turf matting or riprap to avoid
future problems with erosion.
Stone verge is clogged or
Remove sediment and clogged
covered in sediment (if
stone and replace with clean stone.
applicable).
Form SW401-Bioretention O&M-Rev.3 Page 1 of 4
BMP element:
Potentialproblems:
How I will remediate theproblem:
The pretreatment area
Flow is bypassing
Regrade if necessary to route all
pretreatment area and/or
flow to the pretreatment area.
gullies have formed.
Restabilize the area after grading.
Sediment has accumulated to
Search for the source of the
a depth greater than three
sediment and remedy the problem if
inches.
possible. Remove the sediment and
restabilize the pretreatment area.
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.
The bioretention cell:
Best professional practices
Prune according to best professional
vegetation
show that pruning is needed
practices.
to maintain optimal plant
health.
Plants are dead, diseased or
Determine the source of the
dying.
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.
Tree stakes/wires are present
Remove tree stake/wires (which
six months after planting.
can kill the tree if not removed).
The bioretention cell:
Mulch is breaking down or
Spot mulch if there are only random
soils and mulch
has floated away.
void areas. Replace whole mulch
layer if necessary. Remove the
remaining much and replace with
triple shredded hard wood mulch at
a maximum depth of three inches.
Soils and/or mulch are
Determine the extent of the clogging
clogged with sediment.
- remove and replace either just the
top layers or the entire media as
needed. Dispose of the spoil in an
appropriate off -site location. Use
triple shredded hard wood mulch at
a maximum depth of three inches.
Search for the source of the
sediment and remedy the problem if
possible.
An annual soil test shows that
Dolomitic lime shall be applied as
pH has dropped or heavy
recommended per the soil test and
metals have accumulated in
toxic soils shall be removed,
the soil media.
disposed of properly and replaced
with new planting media.
Form SW401-Bioretention O&M-Rev.3 Page 2 of 4
BMP element:
Potentialproblems:
How I will remediate theproblem:
The underdrain system
Clogging has occurred.
Wash out the underdrain system.
(if applicable)
The drop inlet
Clogging has occurred.
Clean out the drop inlet. Dispose of
the sediment off -site.
The drop inlet is damaged
Repair or replace the drop inlet.
The receiving water
Erosion or other signs of
Contact the NC Division of Water
damage have occurred at the
Quality 401 Oversight Unit at 919-
outlet.
733-1786.
Form SW401-Bioretention O&M-Rev.3 Page 3 of 4
Permit Number:
(to be provided by DWQ)
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 DWQ of any
problems with the system or prior to any changes to the system or responsible party.
Project name:
BMP drainage area number:
Print name:
Title:
Address:
Phone:
Signature:
Date:
Note: The legally responsible party should not be a homeowners association unless more than 50% of
the lots have been sold and a resident of the subdivision has been named the president.
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 bioretention maintenance requirements. Witness my hand and official seal,
SEAL
My commission expires
Form SW401-Bioretention 1&M-Rev. 2 Page 4 of 4
Permit Number:
(to be provided by DWQ)
Drainage Area Number:
Dry Extended 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 dry extended detention basin system is defined as the dry detention basin, outlet
structure, pretreatment including forebays and the vegetated filter if one is provided.
This system (check one):
❑ does ❑ does not incorporate a vegetated filter at the outlet.
This system (check one):
❑ does ❑ does not incorporate pretreatment other than a forebay.
Important maintenance procedures:
— The drainage area will be managed to reduce the sediment load to the dry
extended detention basin.
— Immediately after the dry extended detention basin is established, the vegetation
will be watered twice weekly if needed until the plants become established
(commonly six weeks).
— No portion of the dry extended detention pond will be fertilized after the first
initial fertilization that is required to establish the vegetation.
— I will maintain the vegetation in and around the basin at a height of
approximately six inches.
— Once a year, a dam safety expert will inspect the embankment.
After the dry extended detention basin is established, it will be inspected once a quarter
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 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.
BMP element:
Potentialproblem:
How I will remediate theproblem:
The entire BMP
Trash/ debris is present.
Remove the trash/ debris.
The perimeter of the dry
Areas of bare soil and/or
Regrade the soil if necessary to
extended detention
erosive gullies have formed.
remove the gully, and then plant a
basin
ground cover and water until it is
established. Provide lime and a
one-time fertilizer application.
Form SW401-Dry Detention O&M-Rev.3 Page 1 of 4
BMP element:
Potentialproblem:
How I will remediate theproblem:
The inlet device: pipe or
The pipe is clogged (if
Unclog the pipe. Dispose of the
swale
applicable).
sediment off -site.
The pipe is cracked or
Replace the pipe.
otherwise damaged (if
applicable).
Erosion is occurring in the
Regrade the swale if necessary to
swale (if applicable).
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
Search for the source of the
and reduced the depth to 75%
sediment and remedy the problem if
of the original design depth
possible. Remove the sediment and
(see diagram below).
dispose of it in a location where it
will not cause impacts to streams or
the BMP.
Erosion has occurred or
Provide additional erosion
riprap is displaced.
protection such as reinforced turf
matting or riprap if needed to
revent future erosion problems.
Weeds are present.
Remove the weeds, preferably by
hand. If pesticides are used, wipe
them on the plants rather than
spraying.
The main treatment area
Sediment has accumulated
Search for the source of the
and reduced the depth to 75%
sediment and remedy the problem if
of the original design depth
possible. Remove the sediment and
(see diagram below).
dispose of it in a location where it
will not cause impacts to streams or
the BMP. Revegetate disturbed
areas immediately with sod
(preferred) or seed protected with
securely staked erosion mat.
Water is standing more than
Check outlet structure for clogging.
5 days after a storm event.
If it is a design issue, consult an
appropriate rofessional.
Weeds and noxious plants are
Remove the plants by hand or by
growing in the main
wiping them with pesticide (do not
treatment area.
spray).
Form SW401-Dry Detention O&M-Rev.3 Page 2 of 4
BMP element:
Potentialproblem:
How I will remediate theproblem:
The embankment
Shrubs or trees have started
Remove shrubs or trees
to grow on the embankment.
immediately.
Grass cover is unhealthy or
Restore the health of the grass cover
eroding.
- consult a professional if necessary.
Signs of seepage on the
Consult a professional.
downstream face.
Evidence of muskrat or
Use traps to remove muskrats and
beaver activity is present.
consult a professional to remove
beavers.
An annual inspection by an
Make all needed repairs.
appropriate professional
shows that the embankment
needs repair.
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 NC Division of Water
damage have occurred at the
Quality 401 Oversight Unit at 919-
outlet.
733-1786.
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 basin depth reads
When the basin depth reads
Sediment Removal
feet in the main pond, the sediment shall be removed.
feet in the forebay, the sediment shall be removed.
BASIN DIAGRAM
ill in the blanks)
--------------T- m plue,
Bottom Elevatioi 25 /o
Sediment
Storage
FOREBAY
Temporary Pool Elevation
Pool emP D
ora
Sediment Removal Elevation Volume
Bottom Elevation 1 25%
MAIN POND
Form SW401-Dry Detention O&M-Rev.3 Page 3 of 4
Permit Number:
(to be provided by DWQ)
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 DWQ of any
problems with the system or prior to any changes to the system or responsible party.
Project name:
BMP drainage area number:
Print name:
Title:
Address:
Phone:
Signature:
Date:
Note: The legally responsible party should not be a homeowners association unless more than 50% of
the lots have been sold and a resident of the subdivision has been named the president.
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 dry detention basin maintenance requirements. Witness my hand and official
seal,
SEAL
My commission expires
Form SW401-Dry Detention O&M-Rev.3 Page 4 of 4
Permit Number:
(to be provided by DWQ)
Drainage Area Number:
Filter Strip, Restored Riparian Buffer and Level Spreader
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.
Important maintenance procedures:
— Immediately after the filter strip is established, any newly planted vegetation
will be watered twice weekly if needed until the plants become established
(commonly six weeks).
— Once a year, the filter strip will be reseeded to maintain a dense growth of
vegetation
— Stable groundcover will be maintained in the drainage area to reduce the
sediment load to the vegetation.
— Two to three times a year, grass filter strips will be mowed and the clippings
harvested to promote the growth of thick vegetation with optimum pollutant
removal efficiency. Turf grass should not be cut shorter than 3 to 5 inches and
may be allowed to grow as tall as 12 inches depending on aesthetic requirements
(NIPC,1993). Forested filter strips do not require this type of maintenance.
— Once a year, the soil will be aerated if necessary.
— Once a year, soil pH will be tested and lime will be added if necessary.
After the filter strip is established, it will be inspected quarterly and within 24 hours
after every storm event greater than 1.0 inch (or 1.5 inches if in a Coastal County).
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.
BMP element:
Potentialproblem:
How I will remediate theproblem:
The entire filter strip
Trash/ debris is present.
Remove the trash/ debris.
system
The flow splitter device
The flow splitter device is
Unclog the conveyance and dispose
(if applicable)
clogged.
of anysediment off -site.
The flow splitter device is
Make any necessary repairs or
damaged.
replace if damage is too large for
repair.
Form SWU401-Level Spreader, Filter Strip, Restored Riparian Buffer O&M-Rev.3 Page 1 of 3
BMP element:
Potentialproblem:
How I will remediate theproblem:
The Swale and the level
The swale is clogged with
Remove the sediment and dispose
lip
sediment.
of it off -site.
The level lip is cracked,
Repair or replace lip.
settled, undercut, eroded or
otherwise damaged.
There is erosion around the
Regrade the soil to create a berm
end of the level spreader that
that is higher than the level lip, and
shows stormwater has
then plant a ground cover and
bypassed it.
water until it is established. Provide
lime and a one-time fertilizer
application.
Trees or shrubs have begun
Remove them.
to grow on the swale or just
downslo e of the level lip.
The bypass channel
Areas of bare soil and/or
Regrade the soil if necessary to
erosive gullies have formed.
remove the gully, and then
reestablish proper erosion control.
Turf reinforcement is
Study the site to see if a larger
damaged or ripap is rolling
bypass channel is needed (enlarge if
downhill.
necessary). After this, reestablish
the erosion control material.
The filter strip
Grass is too short or too long
Maintain grass at a height of
if applicable).
approximately three to six inches.
Areas of bare soil and/or
Regrade the soil if necessary to
erosive gullies have formed.
remove the gully, and then plant a
ground cover and water until it is
established. Provide lime and a
one-time fertilizer application.
Sediment is building up on
Remove the sediment and
the filter strip.
restabilize the soil with vegetation if
necessary. Provide lime and a one-
time fertilizer application.
Plants are desiccated.
Provide additional irrigation and
fertilizer as needed.
Plants are dead, diseased or
Determine the source of the
dying.
problem: soils, hydrology, disease,
etc. Remedy the problem and
replace plants. Provide a one-time
fertilizer application.
Nuisance vegetation is
Remove vegetation by hand if
choking out desirable species.
possible. If pesticide is used, do not
allow it to get into the receiving
water.
The receiving water
Erosion or other signs of
Contact the NC Division of Water
damage have occurred at the
Quality local Regional Office, or the
outlet.
401 Oversight Unit at 919-733-1786.
Form SWU401-Level Spreader, Filter Strip, Restored Riparian Buffer O&M-Rev.3 Page 2 of 3
Permit Number:
(to be provided by DWQ)
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 DWQ of any
problems with the system or prior to any changes to the system or responsible party.
Project name:
BMP drainage area number:
Print name:
Title:
Address:
Phone:
Signature:
Date:
Note: The legally responsible party should not be a homeowners association unless more than 50% of
the lots have been sold and a resident of the subdivision has been named the president.
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 filter strip, riparian buffer, and/or level spreader maintenance requirements.
Witness my hand and official seal,
SEAL
My commission expires
Form SWU401-Level Spreader, Filter Strip, Restored Riparian Buffer O&M-Rev.3 Page 3 of 3
Permit Number:
(to be provided by DWQ)
Drainage Area / Lot Number:
Permeable Pavement 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.
Important operation and maintenance procedures:
— Stable groundcover will be maintained in the drainage area to reduce the sediment
load to the permeable pavement.
— The area around the perimeter of the permeable pavement will be stabilized and
mowed, with clippings removed.
— Any weeds that grow in the permeable pavement will be sprayed with pesticide
immediately. Weeds will not be pulled, since this could damage the fill media.
— Once a year, the permeable pavement surface will be vacuum swept.
— At no time shall wet sweeping (moistening followed by sweeping) be allowed as a
means of maintenance.
— There shall be no repair or treatment of Permeable Pavement surfaces with other
types of pavement surfaces. All repairs to Permeable Pavement surfaces must be
accomplished utilizing permeable pavement which meets the original pavement
specifications.
— Concentrated runoff from roof drains, piping, swales or other point sources,
directly onto the permeable pavement surface shall not be allowed. These areas
must be diverted away from the permeable pavement.
Initial Inspection: Permeable Pavements shall be inspected monthly for the first three
months for the following:
BMP element:
Potentialproblem:
How to remediate theproblem:
The perimeter of
Areas of bare soil and/or
In the event that rutting or failure of the groundcover
the permeable
erosive gullies have
occurs, the eroded area shall be repaired immediately
pavement
formed.
and permanent groundcover re-established.
Appropriate temporary Erosion Control measures (such
as silt fence) shall be installed in the affected area
during the establishment of permanent groundcover,
and any impacted area of permeable pavement is to be
cleaned via vacuum sweeping.
The surface of the
Rutting / uneven
This indicates inadequate compaction of the pavement
permeable
settlement
base / sub -base. If rutting or uneven settlement on the
pavement
order of'h inch or greater occurs, permeable pavement
shall be removed and base / sub -base re -compacted,
smoothed, and permeable pavement shall then be re-
installed. Base and sub -base compaction shall be
monitored by a licensed geotechnical engineer to ensure
that infiltration capacity of base and sub -base are not
compromised by compaction and smoothing processes.
The pavement does not
Vacuum sweep the pavement. If the pavement still
dewater between storms,
does not dewater, consult a professional.
or water is running off.
Form SW401-Permeable Pavement O&M-Rev.3 Page 1 of 3
Permit Number:
(to be provided by DWQ)
Drainage Area / Lot Number:
The permeable pavement will be inspected once a quarter 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 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.
BMP element:
Potentialproblem:
How to remediate theproblem:
The perimeter of the
Areas of bare soil and/or erosive
Regrade the soil if necessary to remove
permeable pavement
gullies have formed.
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
Maintain vegetation at a height of 3 to 6
long.
inches remove clippings).
The surface of the
Trash/debris is present.
Remove the trash/debris.
permeable pavement
Weeds are growing on the
Do not pull the weeds (may pull out
surface of the permeable
media as well). Spray them with
pavement.
pesticide.
Sediment is present on the
Vacuum sweep the pavement.
surface.
The structure is deteriorating or
Consult an appropriate professional.
damaged.
Damaged areas of the pavement shall be
removed and repaired.
The pavement does not dewater
Vacuum sweep the pavement. If the
between storms.
pavement still does not dewater, consult
a professional. Permanently clogged
pavement shall be removed and
repaired.
Form SW401-Permeable Pavement O&M-Rev.3 Page 2 of 3
Permit Number:
(to be provided by DWQ)
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 DWQ of any
problems with the system or prior to any changes to the system or responsible party.
Project name:
BMP drainage area or lot number:
Print name:
Title:
Address:
Phone:
Signature:
Date:
Note: The legally responsible party should not be a homeowners association unless more than 50% of
the lots have been sold and a resident of the subdivision has been named the president.
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 permeable pavement maintenance requirements. Witness my hand and official
seal,
SEAL
My commission expires
Form SW401-Permeable Pavement O&M-Rev.3 Page 3 of 3
Permit Number:
(to be provided by DWQ)
Drainage Area Number:
Sand Filter 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.
Important maintenance procedures:
— The drainage area will be carefully managed to reduce the sediment load to the
sand filter.
— Once a year, sand media will be skimmed.
— The sand filter media will be replaced whenever it fails to function properly after
vacuuming.
The sand filter 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 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.
BMP element:
Potentialproblem:
How I will remediate theproblem:
The entire BMP
Trash/debris is present.
Remove the trash/debris.
The adjacent pavement
Sediment is present on the
Sweep or vacuum the sediment as
(if applicable)
pavement surface.
soon as possible.
The perimeter of the
Areas of bare soil and/or
Regrade the soil if necessary to
sand filter
erosive gullies have formed.
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
Maintain vegetation at a height of
long.
approximatel six inches.
The flow diversion
The structure is clogged.
Unclog the conveyance and dispose
structure
of any sediment off -site.
The structure is damaged.
Make any necessary repairs or
replace if damage is too large for
repair.
The pretreatment area
Sediment has accumulated to
Search for the source of the
a depth of greater than six
sediment and remedy the problem if
inches.
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 a pesticide is used, wipe it
on the plants rather than spraying.
Form SW401-Sand Filter O&M-Rev.3 Page 1 of 3
BMP element:
Potentialproblem:
How I will remediate theproblem:
The filter bed and
Water is ponding on the
Check to see if the collector system
underdrain collection
surface for more than 24
is clogged and flush if necessary. If
system
hours after a storm.
water still ponds, remove the top
few inches of filter bed media and
replace. If water still ponds, then
consult an expert.
The outflow spillway
Shrubs or trees have started
Remove shrubs and trees
and pipe
to grow on the embankment.
immediately.
The outflow pipe is clogged.
Provide additional erosion
protection such as reinforced turf
matting or riprap if needed to
prevent future erosion problems.
The outflow pipe is damaged.
Repair or replace the pipe.
The receiving water
Erosion or other signs of
Contact the NC Division of Water
damage have occurred at the
Quality 401 Oversight Unit at 919-
outlet.
733-1786.
Form SW401-Sand Filter O&M-Rev.3 Page 2 of 3
Permit Number:
(to be provided by DWQ)
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 DWQ of any
problems with the system or prior to any changes to the system or responsible party.
Project name:
BMP drainage area number:
Print name:
Title:
Address:
Phone:
Signature:
Date:
Note: The legally responsible party should not be a homeowners association unless more than 50% of
the lots have been sold and a resident of the subdivision has been named the president.
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 sand filter maintenance requirements. Witness my hand and official seal,
SEAL
My commission expires
Form SW401-Sand Filter O&M-Rev.3 Page 3 of
Permit Number:
(to be provided by DWQ)
Drainage Area Number:
Stormwater Wetland 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.
Important maintenance procedures:
— Immediately after the stormwater wetland is established, the wetland plants will
be watered twice weekly if needed until the plants become established
(commonly six weeks).
— No portion of the stormwater wetland will be fertilized after the first initial
fertilization that is required to establish the wetland plants.
— Stable groundcover will be maintained in the drainage area to reduce the
sediment load to the wet detention basin.
— Once a year, a dam safety expert will inspect the embankment.
After the wet detention pond is established, I will inspect it 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 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.
BMP element:
Potentialproblem:
How I will remediate theproblem:
The entire BMP
Trash/ debris is present.
Remove the trash/ debris.
The perimeter of the
Areas of bare soil and/or
Regrade the soil if necessary to
wetland
erosive gullies have formed.
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
Maintain vegetation at a height of
long.
approximately six inches.
The inlet device: pipe or
The pipe is clogged (if
Unclog the pipe. Dispose of the
swale
applicable).
sediment off -site.
The pipe is cracked or
Replace the pipe.
otherwise damaged (if
applicable).
Erosion is occurring in the
Regrade the swale if necessary to
swale (if applicable).
smooth it over and provide erosion
control devices such as reinforced
turf matting or riprap to avoid
future problems with erosion.
Form SW401-Wetland O&M-Rev.3 Page 1 of 4
BMP element:
Potentialproblem:
How I will remediate theproblem:
The forebay
Sediment has accumulated in
Search for the source of the
the forebay to a depth that
sediment and remedy the problem if
inhibits the forebay from
possible. Remove the sediment and
functioning well.
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 a pesticide is used, wipe it
on the plants rather than spraying.
The deep pool, shallow
Algal growth covers over
Consult a professional to remove
water and shallow land
50% of the deep pool and
and control the algal growth.
areas
shallow water areas.
Cattails, phragmites or other
Remove the plants by wiping them
invasive plants cover 50% of
with pesticide (do not spray) -
the deep pool and shallow
consult a professional.
water areas.
Shallow land remains flooded
Unclog the outlet device
more than 5 days after a
immediately.
storm event.
Plants are dead, diseased or
Determine the source of the
dying.
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.
Best professional practices
Prune according to best professional
show that pruning is needed
practices.
to maintain optimal plant
health.
Sediment has accumulated
Search for the source of the
and reduced the depth to 75%
sediment and remedy the problem if
of the original design depth
possible. Remove the sediment and
of the deep pools.
dispose of it in a location where it
will not cause impacts to streams or
the BMP.
Form SW401-Wetland O&M-Rev.3 Page 2 of 4
BMP element:
Potentialproblem:
How I will remediate theproblem:
The embankment
A tree has started to grow on
Consult a dam safety specialist to
the embankment.
remove the tree.
An annual inspection by an
Make all needed repairs.
appropriate professional
shows that the embankment
needs repair.
Evidence of muskrat or
Use traps to remove muskrats and
beaver activity is present.
consult a professional to remove
beavers.
The micropool
Sediment has accumulated
Search for the source of the
and reduced the depth to 75%
sediment and remedy the problem if
of the original design depth.
possible. Remove the sediment and
dispose of it in a location where it
will not cause impacts to streams or
the BMP.
Plants are growing in the
Remove the plants, preferably by
micropool.
hand. If a pesticide is used, wipe it
on the plants rather than spraying.
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 NC Division of Water
damage have occurred at the
Quality 401 Oversight Unit at 919-
outlet.
733-1786.
Form SW401-Wetland O&M-Rev.3 Page 3 of 4
Permit Number:
(to be provided by DWQ)
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 DWQ of any
problems with the system or prior to any changes to the system or responsible party.
Project name:
BMP drainage area number:
Print name:
Title:
Address:
Phone:
Signature:
Date:
Note: The legally responsible party should not be a homeowners association unless more than 50% of
the lots have been sold and a resident of the subdivision has been named the president.
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 stormwater wetland maintenance requirements. Witness my hand and official
seal,
SEAL
My commission expires
Form SW401-Wetland O&M-Rev.3 Page 4 of 4
Permit Number:
(to be provided by DWQ)
Drainage Area Number:
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 ❑ does not incorporate a vegetated filter at the outlet.
This system (check one):
❑ does ❑ 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 (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:
Potentialproblem:
How I will remediate theproblem:
The entire BMP
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
detention basin
erosive gullies have formed.
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
Maintain vegetation at a height of
long.
approximately six inches.
Form SW401-Wet Detention Basin O&M-Rev.3 Page 1 of 4
Permit Number:
(to be provided by DWQ)
Drainage Area Number:
BMP element:
Potentialproblem:
How I will remediate theproblem:
The inlet device: pipe or
The pipe is clogged.
Unclog the pipe. Dispose of the
swale
sediment off -site.
The pipe is cracked or
Replace the pipe.
otherwise damaged.
Erosion is occurring in the
Regrade the swale if necessary to
swale.
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
Search for the source of the
a depth greater than the
sediment and remedy the problem if
original design depth for
possible. Remove the sediment and
sediment storage.
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 pesticide is used, wipe it on
the plants rather than spraying.
The vegetated shelf
Best professional practices
Prune according to best professional
show that pruning is needed
practices
to maintain optimal plant
health.
Plants are dead, diseased or
Determine the source of the
dying.
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 pesticide is used, wipe it on
the plants rather than spraying.
The main treatment area
Sediment has accumulated to
Search for the source of the
a depth greater than the
sediment and remedy the problem if
original design sediment
possible. Remove the sediment and
storage depth.
dispose of it in a location where it
will not cause impacts to streams or
the BMP.
Algal growth covers over
Consult a professional to remove
50% of the area.
and control the algal growth.
Cattails, phragmites or other
Remove the plants by wiping them
invasive plants cover 50% of
with pesticide (do not spray).
the basin surface.
Form SW401-Wet Detention Basin O&M-Rev.3 Page 2 of 4
Permit Number:
(to be provided by DWQ)
Drainage Area Number:
BMP element:
Potentialproblem:
How I will remediate theproblem:
The embankment
Shrubs have started to grow
Remove shrubs immediately.
on the embankment.
Evidence of muskrat or
Use traps to remove muskrats and
beaver activity is present.
consult a professional to remove
beavers.
A tree has started to grow on
Consult a dam safety specialist to
the embankment.
remove the tree.
An annual inspection by an
Make all needed repairs.
appropriate professional
shows that the embankment
needs repair.
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 Division of
damage have occurred at the
Water Quality Regional Office, or
outlet.
the 401 Oversight Unit at 919-733-
1786.
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
sediment shall be removed.
When the permanent pool depth reads
shall be removed.
Sediment Removal
feet in the main pond, the
feet in the forebay, the sediment
BASIN DIAGRAM
ill in the blanks)
------ --- - Volume
Bottom Elevati0 -ft Min.
Sediment
Storage
FOREBAY
Permanent Pool Elevation
Pool
Sediment Removal Elevation Volume
Bottom Elevation
MAIN POND
1-ft
Storage
Form SW401-Wet Detention Basin O&M-Rev.3 Page 3 of 4
Permit Number:
(to be provided by DWQ)
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 DWQ of any
problems with the system or prior to any changes to the system or responsible party.
Project name:
BMP drainage area number:
Print name:
Title:
Address:
Phone:
Signature:
Date:
Note: The legally responsible party should not be a homeowners association unless more than 50% of
the lots have been sold and a resident of the subdivision has been named the president.
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
Form SW401-Wet Detention Basin O&M-Rev.3 Page 4 Of 4