HomeMy WebLinkAboutSW4220201_O&M Agreement/Plan_20220330Operation & Maintenance Agreement
Project Name: Hanes Lake Phase 2
Project Location: 2750 Spicewood Drive Pfafftown NC
Cover Page
Maintenance records shall be kept on the following SCM(s). This maintenance record shall be kept in a log in a knowh 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 & corres
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:I—
Level Spreader - Filter Strip
Quantity:I
Proprietary System ( 3AY-cl_
Quantity:
Treatment Swale
Quantity:
Dry Pond
Quantity:
Disconnected Impervious Surface
Present:
User Defined SCM
Present:
Low Density
Present:
'
onding 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):
o Location(s):
o Location(s):
�s Type:
I 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):
__Email:
Signq-�ure:
Clayton Properties Group, Inc.
Chris Inabinet, VP
221 Jonestown Road
Winston-Salem, NC 27104
(336) 765-9661
cinabinet ajmungo.com
Date:
I , a Notary Public for the State of - r�
County of Y do hereby certify that
�rjQv�,
personally appeared before me this day of and�
acknowledge the due execution of Operations andinte nce greement
Witness my hand and official seal,
CONNIE A. ER
NOTARY Pt BLIC
Davidson my
North Car line
my commission EVii es 04/05/2025
Seal My commission expires dn--75-
STORM-EZ 1 /21 /2022
Version 1.5 O&M Agreement Page 1 of 1
Pro rieta S stern Maintenance Re uirements
How manv devices are
Important operation and maintenance procedures:
- The drainage area will be carefully managed to reduce the sediment load to the StormFilter.
- The sedimentation chamber or forebay will be cleaned out whenever sediment depth exceeds six inches.
The StormFilter system 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
BMP element: I Potential problem: I How to remediate the problem:
Adjacent pavement (if Trash debris is present. Remove the trash/debris.
applicable)
Flow diversion structure I Sediment is present on the Sweep or vacuum the sediment as soon as possible.
pavement surface.
StormFilter Cartridges The structure is clogged.
Unclog the conveyance and dispose of any sediment offsite.
The structure is damaged.
Make any necessary repairs or replace if damage is too large for
repair.
Outlet device Clogging has occurred.
Clean out the outlet device. Dispose of the sediment offsite.
The outlet device is
Repair or replace the outlet device.
damaged
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
StormFilter are causing
Contact the local NCDEQ Regional Office.
erosion or sedimentation in
the receiving water.
All other operation and maintenance activities should be in accordance with Contech's StormFilter Inspection and
Maintenance Procedures document. Any problems that are found shall be repaired immediately. The responsible party
shall have received and understand Contech's StormFilter Inspection and Maintenance Procedures document.
ATTACH MANUFACTURER'S MAINTENANCE MANUAL FOR ALL PROPRIETARY DEVICES
Maintenance on Ba saver Bay -Filter
Due to the high level of pollutant variation and specifically- sediment loading, the unit shall be
inspected at least every other month during the first year of operation to determine loading
and required maintenance intervals. This information can be used to establish an appropriate
maintenance schedule for subsequent years. If soil disturbing activities are being conducted
within the unit's drainage area, inspection frequencies must be increased to once each month
and after rain events of 0.3" and larger. The maintenance cycle of the BayFilter system will be
driven mostly by the actual solids load on the filter. The system Should be periodically
monitored to be certain it is operating correctly.
Indications of the need for maintenance:
• Effluent flow decreasing to below the design flow rate or decrease in treatment below
required levels (e.g., greater than 24hr drain down for a volume based system, or the
detention drain down time- whichever is greater).
• Filter cartridge replacement should also be considered when sediment levels are at or
above the level of the manifold system which is G inches and 3 inches for a BayFilter 543
and 545-LP, respectively.
• Bypass occurs during storm events
• If excessive floatables (trash and debris) are present (but no standing water or excessive
sedimentation), perform a minor maintenance consisting of gross solids removal, not
filter media replacement.
• If standing water above the bottom of the filter cartridge is present in the vault 96 hours
after a 2 year rainfall event.
• Removal of trash and silt from the pretreatment chamber
Maintenance & Inspection Procedure
• Remove the manhole covers and open all access hatches.
• Before entering the system make sure the air is safe per OSHA Standards or use a
breathing apparatus. Use low 02, high CO, or other applicable warning devices per
regulatory requirements.
• Using a vacuum truck remove any liquid and sediments that can be removed prior to
entry.
• Using a small lift or the boom of the vacuum truck, remove the used cartridges by lifting
them out.
• Any BayFilters that cannot be readily lifted directly out of the vault should be removed
from their location and carried to the lifting point using the Trolley system installed in
the vault (if applicable).
• When all BayFilters are removed, remove the balance of the solids and water; then
loosen the stainless clamps on the Fernco couplings in the pipe manifold; remove the
drain pipes as well. Carefully cap the manifold and the Ferneos and rinse the floor
rernoving the balance of the collected solids.
• Clean the manifold pipes, inspect, and reinstall.
• Install the exchange BayFilters and close all covers.
• BaySaver Technologies, LLC. states that used BayFilter cartridges may be sent back to
there for exchange/recycling and credit on undamaged units. Contact BaySaver
Technologies at 1.800.229.7283 for more information.
• According to 30 TAC 330 or 30 TAC 335, identify any special disposal requirements
associated with spent media, absorbents, or other material to be generated during
routine cleaning/maintenance operations.
• Removed media will be disposed of according to local and state regulations.
Maintenance on Storage System
Underground detention vaults are similar in function as open detention basins. They have
moderate to high maintenance requirements, depending on the extent to which future
maintenance needs are anticipated during the design stage. Responsibilities for both routine
and non -routine maintenance tasks need to be clearly understood and enforced. If regular
maintenance and inspections are not undertaken, the basin will not achieve its intended
purposes.
Inspections. Storage vaults should be inspected at least twice a.year (once during or immediately
following wet weather) to evaluate facility operation. When possible, inspections should be
conducted during wet weather to determine if the vault is meeting the target detention times. In
particular, the vault's flow control device should be regularly inspected for evidence of
clogging, or conversely, for Coo rapid a release. if the design drawdown times are exceeded by
more than 24 hours, then repairs should be scheduled immediately.
Debris and Litter Removal. Debris and litter will accumulate near the vault's flow control device.
Particular attention should be paid to floating debris that can eventually clog the control device
or riser or orifice.
Structural Repairs and Replacement. With each inspection, any damage to the structural
elements of the system (pipes, concrete drainage structures, etc.) should be identified and
repaired immediately.
!Nuisance Control. Standing water within the bottom of the basin can create nuisance conditions
for nearby residents. Odors, mosquitoes, and litter are all occasionally perceived to be
problems. Most of these problems are generally a sign that regular inspections and
maintenance are not being performed.
Sediment Removal. When properly designed, storage vaults will accumulate quantities of
sediment over time. Sediment accumulation is a serious maintenance concern in vaults for
several reasons. First, the sediment gradually reduces available stormwater management
storage capacity within the vault. Second sediment tends to accumulate around the control
device. Sediment deposition increases the risk that the orifice will become clogged, and
gradually reduces storage capacity reserved for pollutant removal. Sediment can also be re-
suspended if allowed to accumulate over time. For these reasons, accumulated sediment needs
to be removed from the lower stage when sediment buildup fills 20% of the volume of the vault
or at least every 10 years.
Manufacturer Contact Information:
ADS/BaySaver Technologies Engineering Department
Email: info'baysaver.com
Phone: 1.8 00.2 2 9.7 2 8 3
Website: http://www.baysaver.com/
Mail or other: 1030 Deer Hollow Drive
Mount Airy, MD 21771
sta,,,-r�rr
Isolator° Row
O&M Manual
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MC-4500
THE MOST ADIVANCED NAME !IU WA TEA MANAGEMENT SOLUTIONS "
�t�ttr
'HE 1SO-LATO-17-Z ROW
INTRODUCTION
An important component of any Stormwater Pollution Prevention
Plan is inspection and maintenance. The StormTech isolator Row is
a technique to inexpensively enhance Total Suspended Solids (TSS)
removal and provide easy access for inspection and maintenance.
THE ISOLATOR ROW
The Isolator Row is a row of StormTech chambers, either SC-160LP,
SC-310, SC-310-3, SC-740, DC-780, MC-3500 or MC-4500 models,
that is surrounded with filter fabric and connected to a closely located
manhole for easy access. The fabric -wrapped chambers provide for
settling and filtration of sediment as storm water rises in the Isolator
Row and ultimately passes through the filter fabric. The open bottom
chambers and perforated sidewalls (SC-310, SC- 310-3 and SC-740
models) allow storm water to flow both vertically and horizontally out of
the chambers. Sediments are captured in the Isolator Row protecting
the storage areas of the adjacent stone and chambers from sediment
accumulation.
Two different fabrics are used for the Isolator Row. A woven geotextile
fabric is placed between the stone and the Isolator Row chambers.
The tough geotextile provides a media for storm water filtration and
provides a durable surface for maintenance operations. It is also
designed to prevent scour of the underlying stone and remain intact
during high pressure jetting_ A non -woven fabric is placed over the
chambers to provide a filter media for flows passing through the
perforations in the sidewall of the chamber. The non -woven fabric is not
required over the SCA fiOLP DC-780, MC-3500 or MC-4500 models as
these chambers do not have perforated side walls.
The Isolator Row is typically designed to capture the "first flush" and
offers the versatility to be sized on a volume basis or flow rate basis.
An upstream manhole not only provides access to the Isolator Row but
typically includes a high flow weir such that storm water flowrates or
volumes that exceed the capacity of the Isolator Row overtop the over
flow weir and discharge through a manifold to the other chambers.
The Isolator Row may also be part of a treatment train. 6y treating
storm water prior to entry into the chamber system, the service life can
be extended and pollutants such as hydrocarbons can be captured.
Pre-treatment best management practices can be as simple as
deep sump catch basins, oil -water separators or can be innovative
storm water treatment devices. The design of the treatment train and
selection of pretreatment devices by the design engineer is often
driven by regulatory requirements. Whether pretreatment is used or not,
the Isolator Row is recommended by StormTech as an effective means
to minimize maintenance requirements and maintenance costs.
Note. See the StormTech Design Manual for detailed information an
designing inlets for a StormTech system, including the Isolator Flow.
Looking down the Isolator Row from the
manhole opening, woven geotextile is shown
between the chamber and stone base.
StormTech Isolator Row with
Overflow Spillway (not to scale)
OPRONAL
PRE-TREATMENT
v STORMTECH
ISOLATOR ROW
'� _ Imo•. 1 _ A
MANHOLE
WFFH
OVERFLOW
WEIR
ECCENTRIC
HEADER
OPTIONAL STORMTECH CHAMBERS
ACCESS l I
INSPECTION
The frequency of inspection and maintenance varies by location. A
routine inspection schedule needs to be established for each individual
location based upon site specific variables. The type of land use (i.e.
industrial, commercial, residential), anticipated pollutant load, percent
imperviousness, climate, etc. all play a critical role in determining the
actual frequency of inspection and maintenance practices.
At a minimum, StormTech recommends annual inspections. Initially,
the Isolator Row should be inspected every 6 months for the first year
of operation. For subsequent years, the inspection should be adjusted
based upon previous observation of sediment deposition.
The Isolator Row incorporates a combination of standard manhole(s) and strategically located inspection ports
(as needed). The inspection ports allow for easy access to the system from the surface, eliminating the need to
perform a confined space entry for inspection purposes.
If upon visual inspection it is found that sediment has accumulated, a stadia rod should be inserted to
determine the depth of sediment. When the average depth of sediment exceeds 3 inches throughout the length
of the Isolator Row, clean -out should be performed.
MAINTENANCE
The Isolator Row was designed to reduce the cost of periodic maintenance. 8y "isolating" sediments to just
one row, costs are dramatically reduced by eliminating the need to clean out each row of the entire storage
bed. If inspection indicates the potential need for maintenance, access is provided via a manhole(s) located on
the end(s) of the row for cleanout. If entry into the manhole is required, please follow local and OSHA rules for a
confined space entries.
Maintenance is accomplished with the JetVac process. The JetVac process utilizes a high pressure water
nozzle to propel itself down the Isolator Row while scouring and suspending sediments. As the nozzle is
retrieved, the captured pollutants are flushed back into the manhole for vacuuming. Most sewer and pipe
maintenance companies have vacuum/JetVac combination vehicles. Selection of an appropriate JetVac nozzle
will improve maintenance efficiency. Fixed nozzles designed for culverts or large diameter pipe cleaning are
preferable. Rear facing jets with an effective spread of at least 45" are best. Most JetVac reels have 400 feet
of hose allowing maintenance of an Isolator Row up to 50 chambers long. The JetVac process shall only
be performed on StormTech Isolator Rows that have AASHTO class 1 woven geotextile (as specified by
StormTech) over their angular base stone.
StormTech Isolator Row (not to scale)
Note: Non -woven fabric is only required over the inlet pipe connection into the end cap for SC-160LP, DC-780, MC-3500 and MC-4500 chamber
models and is not required over the entire Isolator Row.
�C 743,�.O EA ENTIRE. . TOR RQW W"KI
p CSY.aTIry NGSWO `LWDVEN.QEPTE)tT�E —
SGl]a: a- (2.4 m) ON WIDE
sGm:T0.5m1MINWIDE .�
MC4`AD. MC-3'Jutl. DGi`A sGT�Y. i'O'tlERPIPE
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GEOSYNTNETIGS fi01T NON -WORN GEOTE%R E �i
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SUMP DEPTH TBD aY
SITE DESIGN EN.INE.
(2<'1fi0a mm MIN REC 1MENDMj
11
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STEP 1
Inspect Isolator Row for sediment.
A) Inspection ports (if present)
i. Remove lid from floor box frame
ii. Remove cap from inspection riser
iii. Using a flashlight and stadia rod,measure depth of sediment and record results on maintenance log.
iv. If sediment is at or above 3 inch depth, proceed to Step 2. If not, proceed to Step 3.
S) All Isolator Rows
i. Remove cover from manhole at upstream end of Isolator Row
ii. Using a flashlight, inspect down Isolator Row through outlet pipe
1. Mirrors on poles or cameras may be used to avoid a confined space entry
2. Follow OSHA regulations for confined space entry if entering manhole
iii. If sediment is at or above the lower row of sidewall holes (approximately 3 inches), proceed to Step 2.
If not, proceed to Step 3.
STEP 2
Clean out Isolator Row using the JetVac process.
A) A fixed floor cleaning nozzle with rear facing nozzle spread of 45 inches or more is preferable
B) Apply multiple passes of JetVac until backflush water is clean
C) Vacuum manhole sump as required
STEP 3
Replace all caps, lids and covers, record observations and actions.
STEP 4
Inspect & clean catch basins and manholes upstream of the StormTech system.
-1) A)
SAMPLE MAINTENANCE LOG
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Sample Maintenance Contract
StormTech Isolator Row
XXXXX County, NC
Project Name
Location,
Contract Period. , 202X— 202X (Renewable)
Owner: Name
Address
Contact Number
Vendor: Name
Address
Contact Number
XXXXXXXXXX hereby agrees to provide maintenance on the above referenced project for both
the inspection and clean- out of the proposed StormTech Systems. Inspection of the stormwater
treatment systems will be conducted as outlined below to ensure that the systems are performing
as intended and to develop an appropriate site -specific clean -out schedule. Clean -out of the
stormwater treatment systems will be performed as outlined below at a frequency that will
provide optimal system performance on a cost-effective basis. This maintenance contract will
comply with any State regulations that apply to such programs and all waste removed from the
system will be disposed of properly. Inspection and Maintenance shall be in accordance with
the latest "Isolator Row 0&M Manual" modified by the provisions below. The following services
and documentation will be provided:
System Inspection
inspection of the StormTech System will occur semi-annually for a period of two years beginning
upon the installation of the StormTech System. Inspection will consist of measuring the sediment
accumulation in the Isolator Row. Based on the pollutant accumulation information gathered
during t he initial inspection period, a site -specific clean -out schedule will be developed to
determine the frequency of inspections for the remainder of the contract. Clean -out of
the system is to be performed when the average sediment accumulation is between 1"
and 2" in the Isolator Row.
Page 1 of 3
Svstem Clean -Out
Clean -out of the StormTech System will be conducted on a frequency determined by the
aforementioned inspections. Evacuation and disposal of captured pollutants will be
achieved through an appropriate manner in accordance with any governing State and local
regulations -
Reporting
A document describing the below bulleted items will be prepared after each inspection and
provided to the responsible contact as design at ed by the site owner. If required, a report will
be provided t❑ the relevant State Department after maintenance procedures so that a record
is on file at that location.
@ Accumulated sediment and debris volume
■ Maintenance recommendations
Other relevant observations
Maintenance Costs
Inspection - $ ## per visit
Clean -Out** - $ ## per clean -out per linear foot of Isolator Row
Authorized Representative Date Site Owner Date
Signature of this form constitutes a binding agreement to the terms and fees
Page 2 of 3
Sam le Maintenance Loci
Page 3 of 3
Low ❑ensii 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
SCM element:
Potential problem;
Vegetation
Vegetation is too sl-
too long.
Trash/debris is pre
Areas of bare soil
Vegetated receiving
erosive gullies hav
formed.
areas
Trees and/or other
vegetation are pre
the swale.
Trash/debris is pre
Areas of bare soil
How to remediate the problem:
sort or
Maintain grassed vegetation such that the swale or vegetated
area does not erode during the peak flow from the 10-year
storm
sent. Remove the trash/debris
and/or Regrade the soil if necessary to remove the gully, and then re-
sod (or plant with other appropriate species) and water until
established. Provide lime and a one-time fertilizer application.
woody Remove the trees and woody vegetation from the swale,
sent in regrade the swale if necessary and re-establish grass as shown
on the approved plans.
sent. I Remove the trash/debris.
a
he grass Remove sediment and dispose in an area that will not impact
e swale. streams or SCMs. Re -sod if necessary.
Regrade the slopes to the permitted configuration per the
teeper approved plan and reestablish vegetation. If as -built or existing
conditions do not allow the slopes to be regraded, contact the
applicable permitting agency.
Determine the source of the problem: soils, hydrology. disease.
eased etc. Remedy the problem and replace plants. Provide a one-
time fertilizer application to establish the ground cover if
I necessary.
Wpody Remove the trees and woody vegetation from the vegetated
sent in conveyance, regrade the vegetated conveyance if necessary
and re-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
applicable)
The receiving water
The outlet device is
damaged
Erosion or other signs of
damage have occurred at
the outlet.
Discharges from the site
are causing erosion or
sedimentation in the
receiving water.
Repair or replace the outlet device.
Repair the damage and improve the flow dissipation structure.
Contact the local NCDEQ Regional Office.