HomeMy WebLinkAbout2015-01-06 O & M Report 12/2014 DTO SP Horsley Witten Group 1�
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O&M Report
West Hill Redevelopment
4W High Street
North Andover, MA
December 2014
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Somerville MA 02143
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TABLE OF CONTENTS
Page
1.0 INTRODUCTION 2
2.0 RESPONSIBILTY FOR OPERATION AND MAINTENANCE 3
3.0 MAINTENANCE/INSPECTION SCHEDULE AND TASK 3
3.1 Conveyance Structures 4
3.2 Pretreatment Practices 4
3.3 Stormwater Treatment Practices 5
3.4 Routine Maintenance 8
4.0 LONGTERM POLLUTION PREVENTION PLAN 10
5.0 ESTIMATED OPERATION AND MAINTENANCE BUDGET 12
APPENDICES
Appendix A: Inspection Forms
Appendix B: Site Plans
Appendix C: Storm Tree manufacturer O&M Recommendations
Appendix D: StormTech manufacturer 0&M Recommendations
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North Andover, MA December 2014
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WEST MILL REDEVELOPMENT
STORMWATER OPERATION AND MAINTENANCE PLAN
1.0 INTRODUCTION
All stormwater management and controls are to be operated and maintained appropriately
during regular operation of the site in the post-construction period. The Property Owner and/or
Property Management Company is to provide, inspect, and maintain all stormwater
management and controls.
The following document provides the operation and maintenance (O&M) requirements for the
permanent stormwater management system for West Mill Redevelopment the stormwater
controls identified in the plan provided in Appendix A, will be inspected regularly to prevent
deficiencies in the effectiveness of the systems due to sediment build-up, damage, or
deterioration. Permanent stormwater controls are to be operated and maintained
appropriately during the regular operation of the site in the post-construction period as well as
during the construction phase of the project.
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2.0 RESPONSIBILITY FOR OPERATION AND MAINTENANCE
Owner: RCGLLC
Contact: Responsible party tobg designated byRGC
The owner is responsible for the continuous operation and maintenance of the stornmvvater
BK0Ps and associated drainage areas.
3.8 [NA|NTE0ANCE/|NSPECT|ON SCHEDULE AND TASKS
The maintenance objective for these practices includes maintaining the hydraulic and pollutant
removal capacity of the systems and maintaining healthy native, vegetative cover. This section
describes the required O&M measures for each site. Also included is 8 plan showing the
location of the items tobginspected and maintained, 8swell a5B specific O&M checklist that
Maintenance Staff will use during inspections.
During the six months immediately after construction, all BK4P retrofit practices should be
inspected monthly as well as after precipitation events of at least 1.0 inch to ensure that the
system is functioning p[ope[ly. The following activities are recommended during the first six
month after construction:
• Inspection of flume inlet, swale, sediment forebay weir, and side slopes for erosion
gullying. Repair/re-vegetate as necessary.
• Proper grass seed establishment and satisfactory growth. Additional loam and
overseeding may be required within the first b months to correct bare spots and thin
growth.
• Watering aS required toestablish and maintain grass.
• Loam and seed any void areas or washouts along the biwretentinnbcd caused by
precipitation runoff.
Thereafter, inspections shall be conducted twice annually (spring and fall) and after major
storm events, which are those greater than or equal to the 1-year, 24-hour precipitation event
(~Z.5" iO Essex CoVDty). Th2 following tasks are recommended Bs specified or as needed basis
and broken into four main categories as identified on the attached O&M Site Plan.
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3.1 Drainage Conveyance Structures (inflow/Outflow)
• Flume Inlet 0 Overflow Structure
• Sidewalk Trench Grates * Spillways
• Diversion Structures 0 Inline Drain
• Underdrains 9 Drainage Pipes
All drainage conveyance structures should be inspected twice annually (spring and fall) and
after major storm events to monitor for proper operation, collection of solids, litter and/or
trash, and structural deterioration. The structures should be cleaned annually, or when the
depth of sediment exceeds one half the depth from the bottom of the invert, and repaired
when required. Flume Inlets, in particular, should be inspected for sediment build-up at
entrances, which may cause blockage and re-direction of flow away from the applicable facility.
Accumulated sediment shall be removed and disposed of properly.
All drainage inlets, catch basins, drain manholes, and oil-water/grit separators will be
inspected at least twice annually (spring & fall) to monitor for proper operation, collection
of solids, litter and/or trash, and structural deterioration. The structures will be cleaned
when the depth of sediment exceeds one half the sump depth, and repaired when required.
Sediments shall be removed by clam-shell or vacuum-truck; they will not be removed by
flushing. Proprietary traps and filters associated with practices shall be maintained as
recommended by the manufacturer. Collected sediment will be disposed of properly in a
pre-approved off-site location.
3.2 Pretreatment Practices
Sediment Forebay: The swale and sediment forebay function as pretreatment for the
primary practice. A general inspection of the swale and forebay shall be conducted twice
anlWally (spring and fall) and after major storm events. Maintenance work consists of the
following:
• Removal of any trash and/or debris.
• Removal of sediment when buildup is greater than or equal to 2 inches. Sediment
should be removed by hand or shovel in both linear sediment forebay (Type 2) and
typical sediment forebay (Type 1). Any plants damaged or removed during sediment
removal should be replaced with the same plant genus and species as shown on
Sheet C-14 of the Construction Plans. Sediment shall be disposed of off-site in a pre-
approved location.
• Correction of any side slope erosion gullying, animal burrowing or slope slumping,
and replanting as necessary.
• Correction of any erosion along the bottom of the swale, particularly near the
sidewalk trench grate. Repair with appropriate material.
• Correct any settling of the weirs/check dams between the sediment forebay and the
primary treatment area. Ensure that weirs/check dams are level. Correct any
erosion that has occurred around the edges of the weir.
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• Remove and replace vegetation as necessary, using the appropriate species as
shown on Sheet C-14 of the Construction Plans.
3.3 Stormwater Treatment Practices
A stormwater treatment system should be regularly inspected to ensure proper performance
and to prevent deficiencies in the effectiveness of the systems due to sediment build-up,
damage, or deterioration. The following operation and maintenance provisions should be
provided:
Filtering Systems
Bioretention Areas
General maintenance of the bioretention area falls under landscaping practices. A general
inspection of the bioretention area shall be conducted twice annually (spring and fall) and after
major storm events. Maintenance work consists of the following:
• Removal of any trash and/or debris.
• Correction of any side slope erosion gullying, animal burrowing or slope
slumping, and replanting as necessary.
• If standing water is observed in the bioretention 48 hours after a storm event,
the top 6 inches of the bioretention soil/mulch area shall be roto-tilled or
cultivated to breakup any hard-packed sediment, and replenished with mulch
and replanted. The underdrain system shall be snaked and/or flushed. Replant
with species as shown on Construction Plans.
• In a worst-case scenario, the entire filter bed may need to be re-installed.
Upon failure, excavate bioretention soil, rake the pea gravel to loosen, inspect
underdrain trench to determine if it has been compromised, repair as
necessary, replace soil, replant, and mulch.
Plant maintenance is critical to the function of the bioretention area and should include the
following:
• Cut back grasses, sedges, and rushes annually in the spring.
• Remove and replace vegetation as necessary, using the appropriate species as
shown the Construction Plans. If at least 50 percent vegetation coverage is not
established after two years, a reinforcement planting should be performed. When
replacing a plant, place the new plant in the same location as the old plant, or as
near as possible to the old location. The exception to this recommendation is if
plant mortality is due to initial improper placement of the plant (i.e., in an area that
is too wet or too dry) or if diseased/infected plant material was used and there is
risk of persistence of the disease or fungus in the soil. The best time to plant is in
early to mid-fall or early to mid-spring. Plants should be planted as soon as possible
after purchase to ensure the best chance of survival. If possible, new plants should
be approximately the same size as those that are being replaced. If surrounding
plants have already become well established, care may need to be given to the new
plants to ensure successful growth.
• Plant Thinning: Separation of herbaceous vegetation rootstock should occur when
over-crowding is observed, or approximately once every 3 years.
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• Mowing: Mowing of the bioretention area is NOT necessary or recommended. By
design, plants in bioretention areas are meant to flourish throughout the growing
season, leaving dry standing stalks during the dormant months. When mowing near
bioretention areas, either use a mulching blade, or point the mower away from the
bioretention area. Fresh grass clippings are high in nitrogen and should not be
applied to bioretention areas, as they will compromise the facility's pollutant
reduction effectiveness.
• Weeding: Weeding should be limited to invasive and exotic species, which can
overwhelm the desired plant community. However, native non-invasive volunteer
species are often desirable, as they add to the diversity of the plant community.
Non-chemical methods (hand pulling and hoeing) are preferable; chemical
herbicides should be avoided.
• Fertilizing: Proper selection of plant species and support during establishment of
vegetation should eliminate the need for fertilizers and pesticides.
• Watering: Watering is necessary during the first few weeks after planting, and
during drought conditions. During drought conditions, plants should be watered a
minimum of every seven to ten days.
• Mulching: Replace mulch every two years, in the early spring. The previous mulch
layer should be removed, and properly disposed of, or roto-tilled into the soil
surface. Mulch layers should not exceed 3" in depth. Avoid blocking inflow
entrance points with mounded mulch or raised plantings. Once a full groundcover is
established, mulching may not be necessary. All barren areas within the extents of
the facility shall be replenished with mulch and re-vegetated to the original design
standards.
Biloretention Maintenance Schedule
General Maintenance
Task Frequency Time of the Year
Min. twice annually (spring
Site Inspection and fall) & after major storm Spring thru Fall
events.
Debris removal Min. once per year& after Spring thru Fall
................
major storm events.
Min. once per year or when
sediment is > 2" in sediment
Sediment removal forebay; Ensure sediment April
does not cause blockage of
flume inlet
Plant Maintenance
Task Frequency Time of the Year
Plant Cutting/Thinning Annually Early Spring
Weeding As needed April-October
Watering Drought conditions only July-August
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Plant Replacement As required Spring or Fall preferred
Fertilizing Should not be required
- ---------------
Mulch Maintenance
Task Frequency Time of the Year
Remove & replace existing Once every two years or as April
mulch required
Min. 2x per year & after
Re-mulch void areas major storm events as July & November
needed
Filter Bed Maintenance
Task Frequency Time of the Year
..........
Tilling As needed if standing water does not
drain after 48 hours
If standing water does not
Soil Media Replacement As needed drain after tilling (see
above)
Snow Removal Not required Not required
Tree Filter Pits (Storm Tree):
Tree Filter Pits maintenance should be performed twice annually (spring and fall).
• Fall after leaves have fallen;
• Spring, following all winter sanding operations.
If winter sanding is not performed or minimal accumulation occurs, yearly maintenance may
only be necessary. During inspection, the structural components of the system, including inlets,
overflow spillway and treatment sumps should be checked for proper function. Maintenance
work consists of the following:
• Remove any debris or trash from the concrete surface and/or grating and properly
dispose.
• Remove any debris, trash or obstacles from curb inlet (throat) opening.
• Remove grating overlying pre-treatment sump and/or frame & grate catch basin.
Remove any bottles, cans or large debris. Evacuate accumulated sand/trash and
other matter with designated equipment.
• Inspect the fiberglass grate opening surrounding the tree trunk to determine if the
exterior trunk is in contact with, or in close proximity to the grate. If so, with the use
of a narrow blade hand saw, powered jigsaw, or other cutting device, increase the
opening by removing portions of the grating material as necessary.
• Remove surface grating surrounding the tree and media bed; remove any visible
debris and trash. Should any accumulated sands or sediment be observed on the
media surface, remove to assure a loose and unobstructed media layer. Sediment
should be removed from the bottom of the structure.
• If overflow/bypass port and piping exist, remove any debris or obstruction
surrounding the atrium grate or exposed inlet.
See also Appendix C (for manufacturer specific recommendations).
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Underground Systems
Underground Storage Chambers (StormTech)
Underground storage systems are to be constructed under the proposed parking lots to provide
localized storm water detention. The treated runoff from the proposed parking lots, roads, and
sidewalks is directed to the underground system. To provide additional pretreatment before
detention an Isolator Row is provided with the chambers.
Storl,nTech systeM inspection and mahitenance shOLJld be performed twice annually (spring and
fa 1l l),
* Fall after leaves have fallen;
* Spring, foHowlng all winter sarlding operations.
If winter sanding is not performed or mililmal accumulation occurs, yearly maintenance may
only be necessary. During inspection, the structural components of the system, including
n'ianholes, inspection ports, Isolator Row, overflow spillway, and storage chambers should be
checked for proper function, Maintenance work consists of the following:
• Removal of any debris or trash.
• Removal of sedh'i'ient from the Isolator Row when buildup is greater than or equal to
an average of 3 inches throughout the length of the Isolator Row. Sedin-lent shoWd
be removed with a .let Vac per manufacturer recommendations. Vaccuuni l-nanhole
sumps to remove sediment buildup. Sediment shall be disposed of off.-site in a pre-
approved location,
See also Appendix D (for manufacturer specific recommendations).
3.4 Other Routine Maintenance
Other routine maintenance should include removal of trash and litter from paved and
perimeter areas, and street sweeping a minimum of once per year after the spring thaw. The
pipes draining the project should be inspected annually for proper operation. Specific
considerations when maintaining the parking lots, roadway surfaces, and grounds are as
follows:
• Pet Waste Removal: Pet waste should be picked up and disposed of properly to
reduce bacteria levels in stormwater.
• Snow Removal: Plowed or shoveled snow piles should not block the flume inlet
structure or be placed in the bioretention area. Note that snow removal is NOT
recommended in the bioretention area.
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• De-Icing: When de-icing compounds are necessary for the parking lot and sidewalk,
the least harmful chemicals should be used. Excessive salting of the parking
lot/sidewalks should be avoided. Use of large amounts of sand should also be
avoided, since it may obstruct the conveyance system. Ice removal is NOT
recommended in the bioretention area.
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4.0 LONG-TERM POLLUTION PREVENTION PLAN
Long-term pollution prevention measures implemented at the each project site will further
reduce pollutants in stormwater discharges after construction. The following practices will be
employed on an on-going basis.
Spill Prevention and Control Measures
To minimize the risk of spills or other accidental exposure of materials and substances to
stormwater runoff, the following material management practices will be used throughout the
project:
• An effort will be made to store only enough products required for operation and
maintenance of the facility.
• All materials stored on-site will be stored in a neat, orderly manner in their appropriate
containers and, if possible, under a roof or other enclosure.
• Products will be kept in their original containers with the original manufacturer's label.
• Substances will not be mixed with one another unless recommended by the
manufacturer.
• Whenever possible, the maximum amount of a product will be used before disposing of
the container.
• Manufacturers' recommendations for proper use and disposal will be followed.
• The site superintendent will be issued the O&M to ensure proper use and disposal of
materials.
To reduce the risk associated with hazardous materials used on the site, the following practices
will be used:
• Products will be kept in original containers unless they are not resealable.
• Original labels and material safety data sheets will be retained and kept on-site; they
contain important product information.
• If surplus product must be disposed of, manufacturers' or local and state recommended
methods for proper disposal will be followed.
Materials or substances listed below may be present on-site for operation and maintenance:
• Materials List:
o Concrete o Cleaning Solvents
o Fertilizers o Wood
o Asphalt o Tar
o Petroleum Based Products o Adhesives
o Paints (enamel and latex) o Sealants
The following product-specific practices will be followed on-site:
• Petroleum Products -All on-site vehicles will be monitored for leaks and receive
preventative maintenance to reduce the chance of leakage. Petroleum products will be
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stored in tightly sealed containers which area clearly labeled. Any asphalt substances
used on-site will be applied according to the manufacturers' recommendations.
• Fertilizers— Fertilizers used will be applied only in the minimum amounts recommended
by the manufacturer. Once applied, fertilizer will be worked into the soil to limit
exposure to stormwater. Products will be stored in a covered shed. The contents of any
partially used bags of fertilizer will be transferred to a sealable plastic bin to avoid spills.
• Paints—All containers will be tightly sealed and stored indoors when not required for
use. Excess paint will not be discharged to the storm and/or sewer system but will be
properly disposed of according to the manufacturers' instructions or state and local
regulations.
• Concrete Trucks—Concrete trucks will not be allowed to wash out or discharge surplus
concrete or drum wash water on the site.
Lawn/Landscaping Maintenance
Lawn and landscaping maintenance will be conducted with minimal use of fertilizers and
pesticides to protect the nearby wetland and water resources. Fertilizer will be applied a
maximum three times during the growing season, and pesticides will be applied sparingly, as
needed, following the manufacturer's directions for application. Any fertilizer/pesticide that
lands on paved surfaces such as sidewalks and/or parking areas will be swept up and removed
immediately to prevent it from entering the storm drain network. Geese will be discouraged
from foraging on the lawn areas to reduce nutrient and bacteria inputs from their droppings.
Pet Waste Management
Residents will be encouraged to pick up after their pets with signage along lawn areas.
Solid Waste Management
An enclosed dumpster with a lid will be provided on-site for solid waste management at the site
during facility operations.
Snow Management/Removal Plan
Plowed snow collected from the roadway and parking area will be not be directed to the
stormwater management system. Winter road salt and/or sand will not be stored on-site and
will be used minimally as necessary for safe driving conditions at the site. Snow storage areas
shall be those identified on the Operation and Maintenance figure. If the identified locations
are insufficient, snow will be transported to appropriate alternate locations on the property as
reqUlred.
Pavement Sweeping Schedules
The roadway and parking area will be swept annually after spring snowmelt.
Illicit Discharges
No sewer pipes or floor drains will be connected to the drainage network. All wastewater will
be connected to in approved locations.
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Personnel Training
All contracted personnel retained for work on site will be given a copy of this Plan and will
receive training in applicable practices and implementation to prevent pollutants from entering
the stormwater system.
5.0 ESTIMATED OPERATION AND MAINTENANCE BUDGET
The estimated average annual operating and maintenance budget for the proposed system is
shown below:
Bioretention Areas/Bioswales (8): $8,000
Source: Center for Watershed Protection (CWP) ($1,000/each)
Underground Chamber Fields (1): $500 ($500/field)
Catch Basins, Drain Manholes, and Recharge Basins (15): $3,000 ($200/basin)
Source: Massachusetts Highway Department
Other Routine Maintenance: $1,000
Removal of trash and litter
Annual street sweeping
Pipe network/outfall inspections
Total: $12,500
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APPENDIX A
Inspections Forms
Bioretention Areas �1-8
Operation and Maintenance Checklist
West Mill Redevelopment
North Andover, Massachusetts
Date:
Time:
Inspector:
Location:
Nlamtenance �"
Maintenance Item � Description� Required?
Conveyance Structures..Inspect annually anal aft&fn 'or storm events'(1 yr storm or greater)
Flume inlet Sidewalk French Grate Overflow Structure
Remove all trash, debris, and sediment from all structures
Debris Cleanout twice annually or when sediment buildup is half the depth
from the invert to the bottom,as applicable.*
Remove sediment from flume inlet regularly or when a
Manholes/Diversion build-up is noticed that impacts inflow. If inlet becomes
Structures/Outlets blocked, the bioretention area will not receive the proper
flow.
Check for settling gullying or erosion. Ensure spillway is
Emergency Spillways level. Repair as necessary if damaged or settling. Return to
design grades.
2 Sediment Forebay-, Inspect annually and after major storm events(1-yr storm or greater)
Debris Cleanout Remove all trash and debris from the swale and forebay.
Sediment/Organic Debris Sediment build-up shall be removed and properly disposed
Removal of when build-up is greater than or equal to 2 inches.*
Side Slopes Repair as necessary if signs of erosion gullies, animal
burrowing, or slumping are observed.
III-established, dead or severely diseased plants will be
Vegetation Maintenance removed and replaced annually. See Sheet LA-1 of
Construction Plans for appropriate species.
Remove sediment,trash, and debris from the grated cover.
Rain Guardian Remove sediment,trash, and debris from storage are with
hand or shovel. Remove and clean filter, repair and replace
as needed.
Maintenance;
Maintenance Item " Qescripton Required?
�Y�N)
1 Bioretention Area Inspect at least bi-annually and after.major storm events.the first year;.then annually'.
and after major storm events (1-yr storm'or greater)
Debris Cleanout Remove all trash and debris from the surface of the
bioretention system.
Side Slopes Repair as necessary if signs of erosion gullies, animal
burrowing, or slumping are observed.
If standing water is observed in the bioretention area 48
Sediment/Organic Debris hours after a storm event,the bottom 6 inches shall be
Removal rototilled or cultivated to breakup any hard-packed
sediment, and replenished with mulch.*
Monitor the bioretention soil for proper pH, erosion, and
aeration. Well-aged (minimum 6 months),shredded
hardwood mulch shall be replaced bi-annually as needed,
Vegetation Maintenance/ and ill-established,dead or severely diseased plants will be
Replacement removed and replaced annually. See Sheet LA-1 of
Construction Plans for appropriate species. Grasses,
sedges, and rushes should be cut back annually in the
spring.
Water Draining properly Ensure standing no standing water for more than 48 hours.
If standing water check cleanouts for clogging or aerate.
4. Routine Grounds Maintenance-Inspect annually
Debris Removal Remove trash from perimeter areas.
Pavement Sweeping Sweep parking lot minimum once a year after spring thaw.
Contributing drainage area Contributing drainage area stabilized
Drainage Network Ensure proper operation.
*Sediment shall be disposed of offsite in a pre-approved location.
Comments:
Actions to be Taken:
Tree Filter Pits (9-10)
Operation and Maintenance Checklist
West Mill Redevelopment
North Andover, Massachusetts
Date:
Time:
Inspector:
Location:
Nlamtenarlce
Ma�nterlance Item � :Descry ton' Required?
p
Conveyance Structures r Inspect annually and after major storm events(I-yr storm or greater)
Curb Inlet Overflow.5tructure
Curb Inlet Remove any debris, trash or obstacles from curb inlet
(throat) opening.
If overflow/bypass port and piping exist, remove any
Outlet Structures debris or obstruction surrounding the atrium grate or
exposed inlet.
2 Treatment Sump inspect annually and after major storm events(1-yr storm or greater)
Remove grating overlying pre-treatment sump and/or
Treatment Sump frame & grate catch basin. Remove any bottles, cans
or large debris. Evacuate accumulated sand/trash and
other matter with designated equipment.
3 Structure-Inspect annually and after major storm events(1-yr storm or.greater)
Remove surface grating surrounding the tree and
media bed; remove any visible debris and trash.
Should any accumulated sands or sediment be
Filter Pit observed on the media surface, remove to assure a
loose and unobstructed media layer. Sediment should
be removed from the bottom of the structure.
IVlaintenance'
Maintenance Item Description; Required?
(Y/N�
Inspect the fiberglass grate opening surrounding the
tree trunk to determine if the exterior trunk is in
contact with, or in close proximity to the grate. If so,
Grates with the use of a narrow blade hand saw, powered
jigsaw, or other cutting device, increase the opening
by removing portions of the grating material as
necessary.
III-established, dead or severely diseased trees will be
Vegetation Maintenance removed and replaced annually. See Landscape Plans for
appropriate species.
4. Routine Grounds Maintenance`=Inspect annually
Debris Removal Remove any debris or trash from the concrete surface
and/or grating and properly disposed.
Pavement Sweeping
Sweep roads and parking lots minimum once a year after
spring thaw.
Drainage Network Ensure proper operation.
Contributing drainage area Contributing drainage area stabilized
*Sediment shall be disposed of offsite in a pre-approved location.
Comments:
Actions to be Taken:
Underground Storage Chambers [11)
Operation and Maintenance Checklist
West Mill Redevelopment
North Andover, Massachusetts
Date:
Time:
Inspector:
Location:
Maintenance ;;
Mantertance Itertt....... ed�
... ......
..........
L Drainage Structures Inspect annually and after major storm y events(1- rstorm or greater)
Inlet Structure Isolator Row outlet Structure
Remove all trash, debris, and sediment from all structures
Debris Cleanout twice annually or when sediment buildup is 3" throughout
the depth of the isolator row, as applicable.*
Remove sediment from inlet structure regularly or when a
Inlet Structure build-up is noticed that impacts inflow. If inlet becomes
blocked, the facility will not receive the proper flow. Look
for areas of clogging at bottom of inlet.
Check for clogging and debris accumulation on outlet
Outlet Structures grates or in bottom of outlet structure. Repair as
necessary.
Sediments are to be removed mechanically from the
Sediment Removal underground chambers where possible, using a JetVac
system per the manufacturers recommendations.
24 Routi.ne Grounds Maintenance Inspect annually.
Debris Removal Remove trash from perimeter areas.
Pavement Sweeping Sweep parking lot minimum once a year after spring thaw.
Drainage Network Ensure proper operation.
Contributing drainage area Contributing drainage area stabilized
*Sediment shall be disposed of offsite in a pre-approved location.
Comments:
Actions to be Taken:
APPENDIX B
Site Plans
APPENDIX C
Storm Tree Manufacturers Recommended Operations and Maintenance
Operation and Maintenance Plan
for
StormTree Tree Filter System
The following Operation and Maintenance (0&M) Plan was prepared by StormTree, LLC to assist the
designated owner/operator provide for the successful long term operation of the tree filter system. It is
understood that the O&M Plan will become effective immediately following construction and system
installation, Maintenance will be performed as described and required by the owner/operator, assignee,
or other third party entity. Maintenance should optimally be performed on a twice yearly basis: in fall
after leaves have fallen; in spring, following all winter sanding operations. If winter sanding operations
are not customarily performed as to impact the system, or minimal accumulation occurs, once yearly
maintenance may only be necessary.
1. Remove any debris or trash from the concrete surface and/or grating.
2. Inspect the fiberglass grate opening surrounding the tree trunk to determine if the exterior trunk is in
contact with, or in close proximity to the grate. If so, with the use of a narrow blade hand saw, powered
jigsaw, or other cutting device, increase the opening by removing portions of the grating material as
necessary.
3. Remove any debris, trash or obstacles from curb inlet (throat) opening.
4. Remove surface grating surrounding the tree and media bed; remove any visible debris and trash.
Should any accumulated sands or sediment be observed on the media surface, remove to assure a loose
and unobstructed media layer.
5. if overflow/bypass port and piping exist, remove any debris or obstruction surrounding the atrium grate
or exposed inlet.
6. Remove grating overlying pre-treatment sump and/or frame & grate catch basin. Remove any bottles,
cans or large debris. Evacuate accumulated sand/trash and other matter with designated
equipment/machinery (e.g., vactor, clamshell bucket, pump). If Land tools are to be used, shovel out as
necessary.
7. Replace all grating and securely fasten any hardware.
8. Complete any required maintenance logs or paperwork.
9. Properly dispose of sands, sediment, debris, and trash.
Although not a proprietary product, the engineered media is a specially blended mixture of several
components formulated to maintain a specific infiltration capacity. Please consult StormTree directly
regarding media addition/replacement.
For additional information please contact StormTree, at 781-534-2218.
I
APPENDIX D
Storm Tech Manufacturers Recommended Operations and Maintenance
Save Valuable Land and Stormffieccft
Detention-Relenlian•Recharge
Protect Water Resources Subsurface Storrnwater Management"'
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lsolatorTm Row O&M Manual
StormTech" Chamber System for Stormwater Management
1 .0 'The, lsolator'm Row
1.1 INTRODUCTION The Isolator Row is typically designed to capture the
An important component of any Stormwater Pollution "first flush" and offers the versatility to be sized on a vol-
Prevention Plan is inspection and maintenance. The ume basis or flow rate basis.An upstream manhole not
StormTech Isolator Row is a patent pending technique only provides aCGOSS to the Isolator Row but typically
to inexpensively enhance Total Suspended Solids(TSS) includes a high flow weir such that storm water flowrates
removal and provide easy access for inspection and or volumes that exceed the capacity of the Isolator Row
maintenance. 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.
By 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 inno-
vative 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
Looking down the Isolator Row from the manhole opening, woven information on designing inlets for a StormTech system,
geotexti/6 is shown between the chamber and stone base. including the Isolator Row.
1.2 THE isoLATor ROW StormTech Isolator Row with Overflow Spillway
The Isolator Row is a row of StormTech chambers, either (riot to scale)
SC-310, SC-740 or MC-3500 models, that is surrounded OPTIONAL
with filter fabric and connected to a closely located man- PRE-TREATMENT
hole 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 STORMTECH
through the filter fabric.The open bottom chambers and ISOLATOR ROW
perforated sidewalls allow storm water to flow both verti-
cally and horizontally out of the chambers. Sediments
are captured in the Isolator Row protecting the storage MANHOLEwA
areas of the adjacent stone and chambers from sedi- WITH
OVERFLOW
ment accumulation. WEIR
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 gootextile
provides a media for storm water filtration and provides ECCENTRIC
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,
OPTIONAL
ACCESS STORMTECH CHAMBERS
.......... 1.11.1.1-11-11111...............
2 Call StormTech at 888.892.2694 or visit our website at www.stormtech.com for technical and product information.
2.0 Isolator Row Inspectilon/Ma ill° StormTech®
2.1 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, per-
cent imperviousness, climate, etc, all play a critical role
in determining the actual frequency of inspection and
maintenance practices.
At a minimum, StormTech recommends annual inspec-
tions, Initially, the Isolator Row should be inspected every
6 rnonths for the first year of operation. For subsequent
years, the inspection should be adjusted based upon !'
previous observation of sediment deposition.
aaw, ,d
The Isolator Row incorporates a combination of standard .:..
manhole(s) and strategically located inspection ports
(as needed).The inspection ports allow for easy access Examples of culvert cleaning nozzles appropriate for Isolator Row
to the system from the surface, eliminating the need to maintenance.(These are not StormTech products.)
perform a confined space entry for inspection purposes.
Maintenance is accomplished with the JetVac process.
If upon visual inspection it is found that sediment has The JetVac process utilizes a high pressure water noz-
accumulated, a stadia rod should be inserted to deter- zle to propel itself down the Isolator Row while scouring
mine the depth of sediment.When the average depth and suspending sediments. As the nozzle is retrieved,
of sediment exceeds 3 inches throughout the length of the captured pollutants are flushed back into the man-
the Isolator Row, clean-out should be performed. hale for vacuuming. Most sewer and pipe maintenance
companies have vacuum/JetVac combination vehicles.
2.2 MAINTENANCE Selection of an appropriate JetVac nozzle will improve
The Isolator Row was designed to reduce the cost of maintenance efficiency. Fixed nozzles designed for cul-
periodic maintenance. By "isolating" sediments to just verts or large diameter pipe cleaning are preferable.
one row, costs are dramatically reduced by eliminating Rear facing jets with an effective spread of at least 45"
the need to clean out each row of the entire storage are best. Most JetVac reels have 400 feet of hose allow-
bed. If inspection indicates the potential need for main- ing maintenance of an Isolator Row up to 50 chambers
tenance, access is provided via a manhole(s) located long.The JetVac process shall only be performed on
on the end(s)of the row for cleanout. If entry into the StormTech Isolator Rows that have AASHTO class 1
manhole is required, please follow local and OSHA rules woven geotextile(as specified by StormTech)over
for a confined space entries, their angular base stone.
StormTech Isolator Row(not to scale)
COVER ENTIRE ROW WITH AASHTO M288
INSPECTION PORT CLASS 2 NON-WOVEN GEOTEXTILE
LOCATION PER ENGINEER'S SC-310-5'(1.5(n)WIDE STRIP
DRAWING SC-740-8'(2.4 m)WIDE STRIP STORMTECH
MC-3500-12.5'(3.8 m)WIDE STRIP END CAP
7-!_�"I,.ZT1" GZIIlZ7ZIZ1lIIIIIZI'
CATCH
BASIN
OR
MANHOLE
u
BY
"
E3N ENG _-
[1tGfN£ER
i SC-310-12'(300 mm)PIPE 2 LAYERS OE WOVEN GEOTEXTILE THAT MEETS AASHTO M288 CLASS 1
"..d. SC-740-24"(600 mm)PIPE REOUIREMEN TS,BETWEEN STONE BASE AND CHAMBERS
MC-350D-24"(600(nm)PIPE SC-310.4'(1.2 m)WIDE STRIP
SC-740-6-6'(1.5 m)WIDE STRIP
MC-3500.8.25'(2.5 rn)WIDE STRIP
... . µ-
. ....... .Call StormTech at 888.892.2694 or visit our Website at www.stormtech.com for technical and product information. 3M
3,0 IIsrdlatar Row Step By StqIIIi Procedures
Step 1) Inspect Isolator Row for sediment StormTech Isolator Row(not to scale)
A) Inspection ports(if present) 1)B) 1)A)
i. Remove lid from floor box frame 2
ii. Remove cap from inspection riser
iii. Using a flashlight and stadia rod,
measure depth of sediment and 71
record results on maintenance log.
iv. If sediment is at, or above, 3 inch
depth proceed to Step 2. It not 4--\ . . .....
proceed to stop 3.
13)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 culvert cleaning nozzle with rear facing nozzle spread of 45 inches or more is preferable
13)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
Sample Maintenance Log
I frame at;grade
Novi int�tallation.Fixed&t lb G
......... .....
9/24/01 0.2 0.1 ft. Some grit felt 5m
... ......... ...........
6/20/025 5.6 0.5 ft. Mucky feel,debris visible in manhole and in ry
Isolator rov,maintenance due
.. ............... . ..... .. ............
7/7/03 0.3 ft 0 System jetted and vacuumed eAjm
... . ................... .................
T h QD
Delenlion-Retenlion-fthafge
Subsurface Stormwater Management
20 Beaver Road,Suite 104 Wethersfield G Connecticut � 06109
860.529.8188 1888.892.2694 fax 866.328.8401 �www.stormlech.corr,
StormTech products are covered by one or more of the following patents: U.S.Patents:5,401,459;5,511,903;5,716,163;5,588,778;5,839,844;
Canadian Patents:2,158,418 Other U.S.and Foreign Patents Pending Printed inU.S.A.
Copyright All fights reserved.StormTech LLC,2009 S090809