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Merrimack College
315 Turnpike Street
North Andover, MA 01845
978.837.5000
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260 Arsenal Street#2
PO Box 9151
Watertown, MA 02472
617.924.1770
December 3, 2024
Operations i I Merrimack College, North Andover, MA
Table of Contents
ProjectInformation...............................................................................................................iii
SectionA: Source Control ..................................................................................................A-1
Section B: Spill Prevention.................................................................................................B-1
B.1 Initial Notification....................................................................................................................B-1
B.2 Further Notification.................................................................................................................B-1
B.3 Assessment— Initial Containment.....................................................................................B-4
SectionC: Snow Management...........................................................................................C-1
Section D: Maintenance of Stormwater Management Systems.................................... D-1
D.1 Pavement Systems..................................................................................................................D-1
D.1.1 Standard Asphalt Pavement...............................................................................D-1
D.2 Structural Stormwater Management Devices..............................................................D-1
D.2.1 Drain Inlets (Catch Basins/Area Drains).......................................................D-1
D.2.2 Structural Water Quality Devices.....................................................................D-2
D.2.3 Subsurface Infiltration Basins.............................................................................D-2
D.2.4 Stormwater Outfalls...............................................................................................D-3
D.2.5 Roof Drain Leader..................................................................................................D-3
D.3 Vegetated Stormwater Management Devices............................................................D-4
D.3.1 Rain Gardens/ Bioretention Basins.................................................................D-4
D.3.2 Surface Infiltration/ Detention Basins...........................................................D-5
D.3.3 Grass and Gravel Combination Filter Strip...................................................D-6
D.3.4 Vegetated Areas Maintenance..........................................................................D-6
DAIce Rinks......................................................................................................................................D-7
D.4.1 Routine Ice Rink Maintenance...........................................................................D-7
D.4.2 Annual Ice Rink Maintenance............................................................................D-7
Section E: Operations and Maintenance Plan Summary.................................................E-1
E.1 Routine Maintenance Checklists........................................................................................E-1
E.2 Reporting and Documentation..........................................................................................E-1
E.3 Safety Measures.......................................................................................................................E-1
EAMaintenance Budget..............................................................................................................E-1
E.5 Construction Practices Maintenance/ Evaluation Checklist....................................E-2
E.6 Long-term Maintenance/Evaluation Checklist.............................................................E-3
E.7 Maintenance Checklists and Device Location Maps..................................................E-5
Section F: Product Literature.............................................................................................F-1
Section G: Maintenance Agreement..................................................................................G-1
i Table of Contents
Operationsi I Merrimack , MA
Proj'oect Information
Site
Merrimack College
315 Turnpike Street
North Andover, MA 01845
Owner
Merrimack College
315 Turnpike Street
North Andover, MA 01845
978-837-5000
Facility Manager
John Waters
Merrimack College
315 Turnpike Street
North Andover, MA 01845
978-895-3252
Site Contact
Name:
Telephone:
Cell phone:
Email:
iii Project Information
Operations and Maintenance Plan I Merrimack College, North Andover, MA
Section A: Source Control
Operations and Maintenance Plan Merrimack College, North Andover, MA
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Source Control
A comprehensive source control program will be implemented at the Merrimack College,
which includes the following components:
Regular pavement sweeping
> Catch basin cleaning
> Clearing litter from the parking area, islands, and perimeter landscape areas
> Enclosure and regular maintenance of all dumpsters
> Spill Prevention training
A-1 Source Control
Operations and Maintenance Plan I Merrimack College, North Andover, MA
Section B: Spill Prevention
Operationsintenance PlanMerrimackAndover, MA
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B Spill Prevention
Spill prevention equipment and training will be provided by Merrimack College.
IIIII . ilt III ' IIIII' III ' IIIII o�n
In the event of a spill the facility and/or construction manager or supervisor will be notified
immediately.
Facility Manager (name): John Waters— Merrimack College
Facility Manager (phone): 978-895-3252
Construction Manager (name) : TBD
Construction Manager (phone): TBD
The supervisor will first contact the Fire Department and then notify the Police Department,
the Public Health Commission and the Conservation Commission. The Fire Department is
ultimately responsible for matters of public health and safety and should be notified
immediately.
0u ' I ilfil c at ii o�n
Based on the assessment from the Fire Chief, additional notification to a cleanup contractor
may be made. The STATE Department of Environmental Protection (DEP) and the EPA may
be notified depending upon the nature and severity of the spill. The Fire Chief will be
responsible for determining the level of cleanup and notification required. The attached list
of emergency phone numbers shall be posted in the main construction/facility office and
readily accessible to all employees.A hazardous waste spill report shall be completed as
necessary using the attached form.
B-1 Spill Prevention
Operations i to IMerrimack College, North Andover, MA
Emergency Notification Phone Numbers
1. FACILITY MANAGER
Name: John Waters Phone: 978-895-3252
Beeper/Cell:
Home Phone:
Alternate Contact: Phone:
Beeper/Cell:
Home Phone:
2. FIRE & POLICE DEPARTMENT Emergency: 911
3. CLEANUP CONTRACTOR
Address: TBD Phone: TBD
4. MASSACHUSETTS DEPARTMENT OF ENVIRONMENTAL Emergency: 1-(888) 304-1133
PROTECTION (DEP)
5. NATIONAL RESPONSE CENTER Phone: (800) 424-8802
Alternate: U.S. Environmental Protection Agency Emergency:
Business:
6. MUNICIPAL DEPARTMENTS
Andover Board of Health Phone: (978) 623-8640
Andover Conservation Commission Phone: (978) 623-8630
North Andover Board of Health Phone: (978) 688-9540
North Andover Conservation Commission Phone: (978) 688-9530
B-2 Spill Prevention
Operations and Maintenancel Merrimack College, , MA
Hazardous Waste & Oil Spill Report
Date: Time: AM/PM
Exact location
(Transformer#):
Type of equipment: Make: Size:
S/N: Weather Conditions:
On or near water? ❑ Yes If es, name of body of water:
❑ No y y
Type of chemical/oil spilled:
Amount of chemical/oil spilled:
Cause of spill:
Measures taken to
contain or clean up spill:ill:
Amount of chemical/oil recovered: Method:
Material collected as a result of cleanup:
drums containing
drums containing
drums containing
Location and method of debris disposal:
Name and address of any person, firm,
or corporation suffering charges:P 9 9
Procedures, method,and precautions
instituted to prevent a similar occurrence
from recurring:
Spill reported by General Office by: Time: AM/ PM
Spill reported to DEP/National Response Center b
P P P Y
DEP Date: Time: AM/ PM InsP ector:
N RC Date: Ti me: AM/ PM I nsP ector:
Additional comments:
6-3 Spill Prevention
Operationsi c l MerrimackAndover, MA
Assessment .°°°°°°°°°. ��hniltiI4��
The supervisor or manager will assess the incident and initiate containment control measures
with the appropriate spill containment equipment included in the spill kit kept on-site.A list
of recommended spill equipment to be kept on site is included on the following page.
Fire/ Police Department: 911
Andover Board of Health (978) 623-8640
Andover Conservation Commission (978) 623-8630
North Andover Board of Health (978) 688-9540
North Andover Conservation Commission: (978) 688-9530
Emergency Response Equipment
The following equipment and materials shall be maintained at all times and stored in a
secure area for long-term emergency response need.
Supplies Quantity Recommended Suppliers
Sorbent Pillows/"Pigs" 2 a .ne cm........................
Item#KIT276 —mobile container with two pigs
Sorbent Boom/Sock 25 feet forestr _supIlieirs.corn
.III... a
Sorbent Pads 50
Lite-Dri® Absorbent 5 pounds
Shovel 1 Item#33934—Shovel (or equivalent)
Pry Bar 1 Item#43210—Manhole cover pick(or equivalent)
Goggles 1 pair Item#23334—Goggles(or equivalent)
Gloves— Heavy 1 pair Item#90926—Gloves (or equivalent)
B-4 Spill Prevention
Operations and Maintenance Plan I Merrimack College, North Andover, MA
Section C: Snow Management
Operations and Maintenance Plan Merrimack College, North Andover, MA
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C Snow Management
Prohibited snow storage areas are shown on the attached Snow Storage Area Map in section
E.5 Maintenance Checklists and Device Location Maps.
Snow storage areas will be managed to prevent blockage of storm drain catch basins and
stormwater drainage swales. Snow combined with sand and debris may block a storm
drainage system, diminishing the infiltration capacity of the system and causing localized
flooding.
> Sand and debris deposited on vegetated or paved areas shall be cleared from the site
and properly disposed of at the end of the snow season, no later than May 15.
> Snow shall not be dumped into any waterbody, pond, or wetland resource area.
C-1 Snow Management
Operations and Maintenance Plan I Merrimack College, North Andover, MA
Section D: Maintenance of Stormwater
Management Systems
Operations and Maintenance Plan Merrimack College, North Andover, MA
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D Maintenance of Stormwater Management
Systems
�D.1 ��,Davement Systems
D.11.11 Standa Irnen'tI
> Sweep or vacuum standard asphalt pavement areas at least four times per year with a
rotary brush sweeper, and properly dispose of removed material.
> Recommended sweeping schedule:
o Oct/Nov
o Feb/Mar
o Apr/May
o Aug/Sep
> More frequent sweeping of paved surfaces will result in less accumulation in catch basins,
less cleaning of subsurface structures, and less disposal costs.
> Check loading docks and dumpster areas frequently for spillage and/or pavement
staining and clean as necessary.
1 D.2 Structu4�� Stormwal ter Management )evices
. .1 II ' Ill III Inlets (Catch Baslil III° s/ Area II ' Ill II s
The proper removal of sediments and associated pollutants and trash occurs only when
catch basin inlets and sumps are cleaned out regularly. The more frequent the cleaning, the
less likely sediments will be re-suspended and subsequently discharged. In addition,
frequent cleaning also results in more volume available for future deposition and enhances
the overall performance. As noted in the pavement Operation and Maintenance (O&M)
section, more frequent sweeping of paved surfaces will result in less accumulation in catch
basins, less cleaning of subsurface structures, and less disposal costs.
The catch basin is constructed with a sump (minimum 4 feet) and hooded outlets to trap
debris, sediments, and floating contaminants. The area drains are constructed with sumps
(minimum 2 feet). Disposal of all sediments must be in accordance with applicable local,
D-1 Maintenance of Stormwater Management Systems
Operations and Maintenance Plan I Merrimack College, North Andover, MA
state, and federal guidelines. Catch basin and area drains locations are included in the
Stormwater BMP Location Map included in Section E.5 Maintenance Checklists and Device
Location Maps.
Inspections and Cleaning
All catch basins shall be inspected at least four times per year and cleaned a minimum of
at least once per year.
> Sediment (if more than six inches deep) and/or floatable pollutants shall be pumped from
the basin and disposed of at an approved offsite facility in accordance with all applicable
regulations.
> Any structural damage or other indication of malfunction will be reported to the site
manager and repaired as necessary
> During colder periods, the catch basin grates must be kept free of snow and ice.
> During warmer periods, the catch basin grates must be kept free of leaves, litter, sand,
and debris.
��D.2.2 Structural Wa" II l III" Ili e s
The stormwater drainage system at Merrimack College has structural water quality devices,
which efficiently remove sediment and hydrocarbons from stormwater runoff. A map
showing the locations is included in Maintenance Checklists and Device Location Maps.
> Refer to specific manufacterer's instructions on O&M requirements and methodology
included in Section F.
> Inspect devices monthly for the first three months after construction.
> After initial three-month period, all water quality units are to be inspected at least four
times per year and cleaned a minimum of at least once per year (when sediment reaches
8" in depth).
> Follow manufacturer instructions and contact manufacturer if system is malfunctioning.
Subsurface s I I
The subsurface infiltration/detention basins are used to detain and infiltrate runoff. Some of
these basins has a water quality pre-treatment device in the form of a subsurface sediment
removal row to protect the infiltration bed from clogging. The sediment removal row is an
integral part of the underground infiltration system and is comprised of a perforated pipe,
wrapped in a filter fabric and surrounded with gravel. To maintain pre-treatment
functionality, this sediment removal row requires regular inspection and cleaning. A map of
the infiltration basin locations is included in Section E.5 Maintenance Checklists and Device
Location Maps.
D-2 Maintenance of Stormwater Management Systems
Operations and Maintenance Plan I Merrimack College, North Andover, MA
Inspections and Cleaning
> The subsurface infiltration systems will be inspected at least twice each year by removing
the manhole/access port covers and determining the thickness of sediment that has
accumulated in the sediment removal row.
If sediment is more than six inches deep, it must be suspended via flushing with clean
water and removed using a vactor truck.
> Manufacturer's specifications and instructions for cleaning the sediment removal row are
provided as an attachment to this section.
> Emergency overflow pipes will be examined at least once each year and verified that no
blockage has occurred.
> System will be observed after rainfalls to see if it is properly draining.
D.2.4 Starmwaterl
The stormwater drainage system at Merrimack College has outfall locations where treated
stormwater is discharged to surface wetlands or swales. A map of these locations is included
in Section E.5 Maintenance Checklists and Device Location Maps.
> Inspect outfall locations monthly for the first three months after construction to ensure
proper functioning and correct any areas that have settled or experienced washouts.
> Inspect outfalls annually after initial three-month period.
> Annual inspections should be supplemented after large storms, when washouts may
occu r.
> Maintain vegetation around outfalls to prevent blockages at the outfall.
> Maintain rip rap pad below each outfall and replace any washouts.
> Remove and dispose of any trash or debris at the outfall.
Roof runoff from buildings at Merrimack College are directed to rain garden units,
subsurface infiltration units, or closed drainage system.
> Perform routine roof inspections quarterly.
> Keep roofs clean and free of debris.
> Keep roof drainage systems clear.
> Keep roof access limited to authorized personnel.
> Clean inlets twice per year or as necessary.
D-3 Maintenance of Stormwater Management Systems
Operations and Maintenancel MerrimackAndover, MA
11
��'13 Vegeta ted Stormwater Management I
eviices
Ill II Gardens II III II� II "�III II III IIns
The rain gardens at Merrimack College are excavated shallow surface depressions planted
with specially-selected native vegetation to treat and capture runoff. Each rain garden is
underlain by a gravel infiltration bed with four-inch perforated pipe underdrains to ensure
adequate drainage. Each rain garden also has an overflow structure leading to the
subsurface infiltration system to handle larger storm volumes. A location map for the rain
gardens can be found in Section E.5 Maintenance Checklists and Device Location Maps.
The vegetation in the rain gardens serves to filter runoff improving water quality and
reducing runoff quantity and the root systems can enhance infiltration.The soil medium
filters out pollutants and allows storage and infiltration of stormwater runoff; and the
infiltration bed provides additional volume control. Properly designed rain gardens may
mimic natural forest ecosystems through species diversity, density and distribution of
vegetation, and the use of native species, resulting in a system that is resistant to insects,
disease, pollution, and climatic stresses.
Rain gardens require routine maintenance (similar to conventional landscaping maintenance)
to ensure that the system both functions well as a stormwater management practice while
also maintaining an aesthetic quality compatible with the surrounding land uses.
Replacement of mulch is an important part of rain garden maintenance. Mulch keeps the soil
moist, allowing for easy infiltration of rain water. Un-mulched surfaces may develop into a
hardpan, a condition in which the soil surface becomes cemented together, forming a hard,
impervious layer. Mulching also protects plants and reduces weed growth.
Initial Post-Construction Inspection
> During the initial period of vegetation establishment pruning and weeding are required
twice in first year by contractor.
> Any dead vegetation found after the first year must be replaced.
> Proper mulching is mandatory and regular watering may be required initially to ensure
proper establishment of new vegetation.
Long-Term Maintenance
> Weeds and invasive plant species shall be removed by hand.
> Leaf litter and other detritus shall be removed twice per year.
> If needed to maintain aesthetic appearance, perennial plantings may be trimmed at the
end of the growing season.
> Trees and shrubs should be inspected twice per year to evaluate health and attended to
as necessary.
> Re-mulch rain gardens with well aged hardwood mulch to a depth of 3 inches each
spring or whenever erosion is evident. The entire area may require mulch replacement
D-4 Maintenance of Stormwater Management Systems
Operations and Maintenance Plan I Merrimack College, North Andover, MA
once every two to three years. Mulch depth shall not exceed 3 inches and the depth of
the depression shall not be compromised by the accumulation of vegetation or old
mulch.
> Seeded ground cover or grass areas shall not receive mulching.
Fertilizers should not be used in the rain garden as excessive nutrients in the rain garden
may migrate to the underdrain and be discharged to adjacent surface waters.
> Test pH of the soils in the planting bed annually. If the pH is below 5.2, limestone should
be applied to increase it. If the pH is above 8.0, iron sulfate plus sulfur should be added
to reduce it.
> Rain gardens may require watering during periods of extended drought.
Inspections and Cleaning
> Rain gardens shall be inspected twice during for the first year and annually thereafter for
sediment buildup, erosion, vegetative conditions, etc. If sediment build-up is found,
sediment removal and core aeration or cultivating of un-vegetated areas may be required
to ensure adequate filtration.
> The inflow location should be inspected annually for clogging. Sediment build up is a
common problem where runoff leaves an impervious surface and enters a vegetative or
earthen surface.Any built-up sediment should be removed to prevent runoff from
bypassing the facility. Sources of sediment should be prevented.
> The overflow structure and underdrain standpipes should be inspected annually to
ensure that they are functioning.
> Inspect rain gardens after a large storm event to ensure that proper drainage is occurring.
Water that remains ponded on the surface of the rain garden after 48 hours of dry
weather could indicate a problem with the subsurface drainage system or clogging of the
underdrain.While the plants selected for the rain garden are tolerant of wet soils, they
are not wetland species that can survive long periods of inundation. Immediate attention
is required to prevent the loss of plant materials.
D.3.2 SurfaceII " III "t III " III II II "t III II "III II
There are two surface detention ponds at Merrimack College: Football Field and Elm Street
Basins.Additional surface infiltration basins throughout the Campus are indicated on the Site
Maps.The detention ponds are partially vegetated basins that are designed to detain and
clean roadway and rooftop runoff.The maintenance of the basins may affect the functioning
of stormwater management practices. This includes the condition of the side slope
vegetation and the sediment deposits in the bottom of the ponds.
Initial Post-construction Inspection
Basins should be inspected after every major storm for the first few months to ensure
proper stabilization and function.
D-5 Maintenance of Stormwater Management Systems
Operations and Maintenance Plan I Merrimack College, North Andover, MA
Long-term Maintenance
The grass on the sideslopes and in the buffer areas should be mowed, and grass
clippings, organic matter, and accumulated trash and debris removed, at least twice
during the growing season.
Eroded or barren spots should be reseeded immediately after inspection to prevent
additional erosion and accumulation of sediment.
> Deep tilling can be used to break up a clogged surface area.
> Sediment should be removed from the basin as necessary. Removal procedures should
not take place until the floor of the basin is thoroughly dry.
Inspections and Cleaning
> Basins should be inspected at least twice a year to ensure proper stabilization and
function.
> Light equipment,which will not compact the underlying soil, should be used to remove
the top layer.
Monitoring
> Monitor outflow from basins in accordance with Stormwater Management Plan
Grass andGravel II lip II " Ill ° II m Ill i" II "tIiII�
Inspect planted areas on a semi-annual basis and remove any litter.
> Inspect filter strip for sediment buildup and the vegetation for signs of erosion, bare
spots, and overall health
> Inspect filter strip bi-annually for the first year and annually thereafter.
> Annual inspections should be supplemented after large storms, when washouts may
occu r.
> Regularly rake and mow the grass to prevent accumulated solids from entering the rain
garden.
Remove sediment from the toe of slope and reseed bare spots.
��D.3.4 Vegetated Areas Mailn'terianceI
Although not a structural component of the drainage system,the maintenance of vegetated
areas may affect the functioning of the stormwater management system.This includes the
health/density of vegetative cover and activities such as the application and disposal of lawn
and garden care products, disposal of leaves and yard trimmings and proper aeration of soils.
> Inspect planted areas on a semi-annual basis and remove any litter.
> Maintain planted areas adjacent to pavement to prevent soil washout.
> Immediately clean any soil deposited on pavement.
D-6 Maintenance of Stormwater Management Systems
Operations and Maintenance Plan I Merrimack College, North Andover, MA
Re-seed bare areas; install appropriate erosion control measures when native soil is
exposed or erosion channels are forming.
> Plant alternative mixture of grass species in the event of unsuccessful establishment.
> The grass vegetation should be cut to a height between three and four inches.
Pesticide/Herbicide Usage— No pesticides are to be used unless a single spot treatment
is required for a specific control application.
> Fertilizer usage should be avoided. If deemed necessary, slow release fertilizer should be
used. Fertilizer may be used to begin the establishment of vegetation in bare or damaged
areas, but should not be applied on a regular basis unless necessary.
> Annual application of compost amendments and aeration are recommended.
��ce ��RiI6�ks
D.4.1 Routiln iFnkIll II ' III° aI c
When ice shavings from the upper layer of the ice or ice from Zamboni machine are to be
disposed, they shall be placed at the location shown on the approved plans only. This
stockpile of ice shall be surrounded by straw wattle on the downslope side.Any accumulated
sediment shall be removed. A map noting this location is included in Section E.5
Maintenance Checklists and Device Location Maps.
DA,2 AnII IIIII Ill II ' II III '°'
For removal of additional ice, including layers, understood to occur on an annual basis and
under emergency scenarios such as a power outage that causes ice melt, the ice layers and
shavings, including the water-based and bio-degradable paint, shall be transported from the
rink to a container on-campus lined in filter fabric and surrounded by crushed stone. This
container must be located outside all 100-ft wetland resource area buffer zones. Upon
completion of the removal, the container and its contents shall be picked up and disposed of
off-site by a third party vendor.A map noting this storage location, and the route to fill and
remove the container, is included in Section E.5 Maintenance Checklists and Device Location
Maps.
D-7 Maintenance of Stormwater Management Systems
Operations and Maintenance Plan I Merrimack College, North Andover, MA
Section E: Operations and Maintenance Plan
Summary
Operations and Maintenance Plan Merrimack College, North Andover, MA
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E Operations and Maintenance Plan Summary
This Operation and Maintenance Plan has been prepared in accordance with the Stormwater
Management Policy developed by the DEP and CZM and local regulations. It specifies
operational practices and drainage system maintenance requirements at Merrimack College.
Requirements should be adjusted by the site manager as necessary to ensure successful
functioning of system components.
11.1 RoutildneChedk���ilsts
Routine required maintenance is described in Sections A— D. The following checklists are to
be used by the property manager to implement and document the required maintenance
and inspection tasks.
��Repartiing and
The site supervisor shall be responsible for ensuring that the scheduled tasks as described in
this plan are appropriately completed and recorded in the Maintenance Log. Accurate
records of all inspections, routine maintenance and repairs shall be documented and these
records shall be available for inspection by members of the Andover and North Andover
Conservation Commissions, or their designated agent, upon request.
The Maintenance Log shall:
> Document the completion of required maintenance tasks.
> Identify the person responsible for the completion of tasks.
> Identify any outstanding problems, malfunctions or inconsistencies identified during the
course of routine maintenance.
Document specific repairs or replacements.
Safety Measures
All maintenance work is to be completed in accordance with Merrimack College safety
requirements, as well as all local, state, OSHA and other federal safety requirements.
Maildn'tenance ��Budget
Merrimack College estimates an approximate annual maintenance budget of$25,000 for
maintenance of stormwater BMPs, in addition to the campus-wide in house maintenance
performed by their Facilities Department.
E-1 Operations and Maintenance Plan Summary
Operations and MaintenanceI Merrimack College, North Andover, MA
Canstrudii � r IIIIIMaildn'tenance/ Che6V�ilst
Merrimack College- North Andover, MA
Cleaning or
Best Repair Needed Date of
Management Inspection Date Inspector Minimum Maintenance ❑Yes/No Cleaning Performed
Practice Frequency Inspected Initials and Key Items to Check (List Items) or Repair by:
Hay Bales/ Weekly and Sediment build up, broken
Silt Fencing after any bales or stakes
rainfall
Gravel Weekly and Filled voids,runoff/sediments
Construction after any into street
Entrance rainfall
Catch Basin Weekly and Clogged or sediment build-
Protection after any up at surface or in basin
rainfall
Diversion Weekly and Maintained,moved as
Channels after any necessary to correct locations,
rainfall Check for erosion or breakout
Temporary Weekly and Cracking,erosion, breakout,
Sedimentation after any sediment buildup,
Basins rainfall contaminants
Stormwater Control Manager:
E-2 Operations and Maintenance Plan Summary
Operations and MaintenanceI Merrimack College, o v , MA
6 ang°°°° IIIII IIIII Che6V�ilst
Merrimack College- North Andover, MA
Minimum Cleaning or
Best Maintenance Repair Date of
Management and Key Items Inspection Date Inspector Cleaning Needed Cleaning or Performed
Practice to Check Frequency Inspected Initials Frequency ❑Yes/No Repair by:
Street Sweeping Vacuum sweeper 4X per year 4X per year*
minimum
Outfall Structures Remove debris and 1X per year 1X per year
excess vegetation,
replace any dislodged
riprap
Deep Sump and Remove sediment 1X 4X per year 1 X per year
Hooded Catch per year or if>6 or as
basins inches necessary
Subsurface Remove sediment 1X 2X per year 1X per year
Infiltration Basins per year or if>6
inches
Rain Gardens/ Inspect inlets, 2X per year 2X per year
Bioretention vegetation,overflow first year, first year,
Basins discharge pipes,drain annually annually
time less than 4 days thereafter thereafter
Surface Mow grass and 2X per year 2X per year
Infiltration/ remove debris and
Detention Basins sediment, reseed bare
spots
Roof Drains Remove debris,clean 4x per year 2x per year
inlets draining to roof inlet
subsurface bed inspection cleaning,
roof debris
as necessary
Water Quality Remove sediment 1x 4x per year 1x per year
Units per year or if>8 or as
inches necessary
Grass and Gravel Rake and mow grass, 1X per year 1x per year
Combination remove sediment or as
Filter Strip from toe of slope and necessary
reseed bare spots
Routine Ice Rink Ensure sediment 1X per year 1X per year
Maintenance controls are in place
on down-gradient
side of stockpiles,
remove any
accumulated
sediment.
E-3 Operations and Maintenance Plan Summary
Operations and MaintenanceI Merrimack College, o v , MA
Annual Ice Rink Ensure storage 1X per year 1X per year
Maintenance locations located
outside of 100-BZ and
container lined with
filter fabric and
surrounded by
crushed stone.
* Recommend sweeping Oct/Nov,Feb/Mar,Apr/May Jul/Aug with late winter most important
Stormwater Control Manager:
E-4 Operations and Maintenance Plan Summary
Operations and Maintenance Plan I Merrimack College, North Andover, MA
......7 Maild ilsts ' IIIII
These checklists are provided for the maintenance crew to photocopy and use when
conducting inspections and cleaning activities to the stormwater management systems.
E-5 Operations and Maintenance Plan Summary
E-6 Operations and Maintenance Plan Summary
Operations Maintenance I Merrimack College, NorthAndover, MA
Drain Inlets (Catch Basins/Area Drains) —Inspect 4 times per year, clean when sediment depth >6 inches
or at least once per year.
Catch
Basin/ Sediment Cleaning
Area I nspected Depth needed Date
Drain (Y/N) (inches) (Y/N) Cleaned Comments(Trash, Oil, Pet waste, Lawn Debris, Damage)
E-7 Operations and Maintenance Plan Summary
Operations Maintenance I Merrimack College, NorthAndover, MA
Outfalls—Inspect 4 times per year, replace any dislodged rip-rap, remove excess vegetation, remove any
Sediment Cleaning
I nspected Depth needed Date
Outfall (Y/N) (inches) (Y/N) Cleaned Comments(Trash,Oil, Pet waste, Lawn Debris, Damage)
E-8 Operations and Maintenance Plan Summary
Operations and MaintenanceI Merrimack College, North Andover, MA
Water Qualilty Units— Inspect 4 ti'mes per year, clean at least once per year or when sediment reaches a
depth of 8 iInches.
Sediment Cleaning
Water Quality Inspected Depth needed Date Comments(Trash, Oil, Pet waste, Lawn Debris,
Unit (Y/N) (inches) (Y/N) Cleaned Damage)
Merrimack Athletic Complex(Volpe Athletic Center Expansion Project)
WQU-Al
WQU 61
South Residential Village (Student Residences Project)
WQU-Al
WQU-61
North Residential Village
WQU-Al
WQU-A2
WQU-A3
Duane Stadium
WQU-121
Arcidi Welcome Center/ Parking Lot A
WQU-Cl
Parking Lot C
WQU-1
Collegiate Church of Christ the Teacher
WQU-6105
Corner Development Project
WQU-Al02
WQU-13102
WQU-Cl11
Lecture Hall
WQU-108
E-9 Operations and Maintenance Plan Summary
Operations and MaintenanceI Merrimack College, North Andover, MA
Subsurface Infiltration Basins- Inspect once per year, remove sediment lif more than 6 inches has
accumulated 'in sediment forebay or sediment collection row.
Sediment Cleaning
Inspected Depth needed Date Comments(Trash, Oil, Pet waste, Lawn Debris,
Basin (Y/N) (inches) (Y/N) Cleaned Damage)
South Residential Village (Student Residences Project)
IS-1
IS-2
IS-3
North Residential Village
IS-1
Corner Development Project
SIS-A
SIS-B
SIS-C
Lecture Hall
SIS-A
E-10 Operations and Maintenance Plan Summary
Operations and MaintenanceI Merrimack College, North Andover, MA
Ram Gardens/Blioretentilon Basilins- Inspect twilice during first year and annually thereafter for sediment
builldup, erosion, vegetative conditions, etc. If sediment builld-up *Is found, core aeration or culfivatilng of
unvegetated areas may be requilred to ensure adequate filltratilon. The overflow should be inspected
annually to ensure thatilitilis functioning.
Sediment Cleaning
Inspected Depth needed Date Comments(Trash, Oil, Pet waste, Lawn Debris,
Rain Garden (Y/N) (inches) (Y/N) Cleaned Damage)
Merrimack Athletic Complex(Volpe Athletic Center Expansion Project)
RG-1
RG-2
Parking Lot C
BB-1
BB-2
BB-3A
BB-3B
B B-4
BB-5
E-11 Operations and Maintenance Plan Summary
Operations Maintenance I Merrimack College, NorthAndover, MA
Grass and Gravel Combination Filter Strip-Inspect twice during first year and annually thereafter for
sediment buildup, erosion,, vegetative conditions,, etc. Regularly rake and mow the grass to prevent
accumulated solids from entering ralin garden. Remove sediment from the toe of slope and reseed bare
Sediment Cleaning
Filter Inspected Depth needed Date
Strip (Y/N) (inches) (Y/N) Cleaned Comments(Trash, Oil, Pet waste, Lawn Debris, Damage)
E-12 Operations and Maintenance Plan Summary
Operations i I Merrimack College, North Andover, MA
Surface Infiltration/Detention Basins- Inspect twice per year, remove sediment and debris.The grass
should be mowed and eroded or barren spots should be reseeded. Deep tilling can be used to break up a
clogged surface area.
Sediment Cleaning
Inspected Depth needed Date Comments(Trash, Oil, Pet waste, Lawn Debris,
Basin (Y/N) (inches) (Y/N) Cleaned Damage)
Main Campus Detention Basins
Football Field Basin
Elm Street Basin
MAC Storage Building
IB-1
E-13 Operations and Maintenance Plan Summary
Operations Maintenance I Merrimack College, NorthAndover, MA
Roof Runoff Downspouts- Inspect roof drams monthly, clean mlets dralinling to the subsurface bed twice
per year.
Sediment Cleaning
I nspected Depth needed Date
Bldg# (Y/N) (inches) (Y/N) Cleaned Comments(Trash, Oil, Pet waste, Lawn Debris, Damage)
E-14 Operations and Maintenance Plan Summary
Operations i to c I Merrimack College, NorthAndover, MA
Routine Ice Rink Maintenance-Inspect once per week, sediment controls are in place on down-gradilent
s ide of stockpiles, remove any accumulated sediment. (As described 'in Section D.4.1)
Sediment Cleaning
Storage I nspected Depth needed Date
Location (Y/N) (inches) (Y/N) Cleaned Comments(Trash, Oil, Pet waste, Lawn Debris, Damage)
Location 1Section
Annual Ice Rink Maintenance-This maintenance is conducted once per year. Storage location is outside
of 100-BZ and container is lined with filter fabric and surrounded by crushed stone. (As described in
. ®
Sediment Cleaning
Storage I nspected Depth needed Date
Location (Y/N) (inches) (Y/N) Cleaned Comments(Trash, Oil, Pet waste, Lawn Debris, Damage)
Container
E-15 Operations and Maintenance Plan Summary
E-16 Operations and Maintenance Plan Summary
a.
Legend
RAIN GARDEN/BIORETENTION BASIN
CATCH BASIN/AREA DRAIN
DOI
CLEAN our
DL DOWNSPOUT RAIN LEADER
g
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1 ES, INFILTRATION BASIN
4
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SEDIMENT FOREBAY
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0SUBSURFACE INFILTRATION SYSTEM
MASSDOT EASEMENT
QQ
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TEMPORARY STORAGE
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Stormwater BMP Location Plan
Merrimack College -
0 62.5 125 250 Feet§ie
North Andover,MA g�h b
Source:VHB
Prepared for Merrimack College
Date:12/11/2024
E-19 Operations and Maintenance Plan Summary
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GENERAL NOTES LF-CAND iall 01
WETLAND BOUNDARIES AND ASSOCIATED BUFFER ZONES 4%" '--"qF"
SHOWN BASED ON A COMPILATION OF THE FOLLOWING:
W
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OWN:b" 2,
A
1 DF INFATION OF THE WETLANDS AND PLACEMENT 1&�17M7 1.WJ
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OIL,
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FT E FLAGS WAS PERFORMED BY:VHB IN JANUARY
2022
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VHB IN JANUARY 2022.
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3. SUPPLEMENTED WITH MA WETLAND BOUNDARIES
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PER MASSGIS,OLIVER ONLINE DATABASE �JN
vhb Snow Storage Restrictions Figure 1
MMEMMM%� Merrimack College
Q4 0 100 200 400 Feet 315 Turnpike St 12/11/2024
North Andover,MA
Operations and Maintenance Plan I Merrimack College, North Andover, MA
0
Section F: Product Literature
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BKP
..................... .... t. --
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When it rains, oils, sediment and other contaminants are captured
and contained by over 20,000 stormce for units operating
worldwide. While storm e tor's patented scour prevention
technology ensures captured pollutants remain in the unit during
all rainfall events, the accumulated pollutants must eventually be
removed as part of a regular maintenance program.
If neglected, oil and sediment gradually build yap and diminish any
I IP's efficiency, harming the environment and leaving owners and
operators vulnerable to fires, surcharges and bad publicity.
Maintenanceis
a rn U,
wi x
x
Ease, frequency and cost of maintenance are often overlooked by
specifiers when considering the merits of a storm water treatment
system. In reality, maintenance is fundamental to the long-terra
performance of any stormwater quality treatment device. v
n
1
h While regular maintenance i crucial it shouldn t
ik
- be complicated. An ongoing maintenance
program with storm ce for is convenient and
f -
practically effortless. With virtually no disruptions, you can concentrate on
your core business.
-_ (zh 11c k i r is p e o ns
............
. ..... .........
Inspections are easily carried out above ground from any standard surface
access cover through a visual inspection of the orifice and drop tee
I
components. A sludge judge and oil dip-stick are all that are needed for
.!ff f 1r
sediment and oil depth measurements.
n �3f} ccec7s--0k bEasy to-
RA,
..........
Maintenance is typically conducted from the sane surface access corer,
: f eliminating the need for confined space entry into the unit. Your site
w
M= + + remains undisturbed, saving you time and money..
r`;•
imbrium
7,. muss,��i��a,k1, o fuss a n d fast
..:.:..�:.... .........................
��
:. ...........
....
Maintenance is performed y� �I nd inexpensivelywith : .;.:: _ ..
.. ..
. ..
..........................
standard vacuum truck* Servicing usually takes less than
two hours, with no disruption to your site. w._... :. :. .::.:::....... ..
w:
77
completet r mw t r management �n
p I for St r r e t r .�. � ... .
extends beyond installation and performance to regular
maintenance. It's the smart, cost-effective y to ensure
Y Y��
X.
your unit continues to remove more pollutants than any M}:��;
tnr separator for decades to come. ME
;: µ }k .w
Or.
w
�yN ..,r �}ems/ �}•,"'v'n :; ,5?lk �'`;,�^;�r III II ..f:Y-°'w.+ �,(,oi�•�'� y'�''���°,�,�
'� ,i*'• 6.> �_xC,}.�.,�.,w"iw'•'.�.• /:i�. ,�, .�Iry.r Llil :.»M1:!{{, n �.
f%f'sk•y.�, "f^u'4 �fn. '%�-•;�"� ^-,r v �. '?�:�;" �uw:::G�h.}*:.�<� k�:�',y-r.. '' r'
^ti:.�Z'�=" w�.bfi. ,o��'�,r^..,L��---� §""S't^•'_5:.- -- ���_. _T�:c.r��v...._.....':s•it tf�:..:�xt�w^_,r_,3oc�_raK'_w w...wa:�.l�Ca�,��`�'T'.
atorrviceptor maintenance recommendations
Units should be inspected post-construction, prior to being put.into service.
• Inspect every six months for the first year of operation to determine the oil and sediment
accumulation rate.
• In subsequent years, inspections can be based on first-year observations or local
requirements.
Cleaning is required once the,sediment depth reaches 5% of storage capacity, (generally
taking one year or longer). Local regulations for maintenance frequency may Crary.
Inspect the unit immediately after an oil, fuel or chemical spill.
• A licensed waste management company should remove captured petroleum waste products
from any oil, chemical or fuel spills and dispose responsibly.
With over 20,000 units operating worldwide, Storm ept r performs and protects every day,
in every stern.
I M 110.r i u m
:........:................................:..'..'..
C%il NT CHe
ENGINEERED SOLUTIONS
CDS Guide
Operation, Design, Performance and Maintenance
................. ..................
................
................................................... .............
JV
.. .... ..
..........
/.........
...........
..........
...........
"Ll
CDS@ Design Basics
Using patented continuous deflective separation technology,the There are three primary methods of sizing a CDS system. The
CDS system screens, separates and traps debris, sediment, and Water Quality Flow Rate Method determines which model size
oil and grease from Stormwater runoff.The indirect screening provides the desired removal efficiency at a given flow rate for a
capability of the system allows for 100% removal of floatables defined particle size.The Rational Rainfall Method TM or the and
and neutrally buoyant material without blinding. Flow and Probabilistic Method is used when a specific removal efficiency of
screening controls physically separate captured solids, and the net annual sediment load is required.
minimize the re-suspension and release of previously trapped
pollutants. Inline units can treat up to 6 cfs, and internally bypass Typically in the Unites States, CDS systems are designed to
flows in excess of 50 cfs (1416 Us). Available precast or cast-in- achieve an 80%annual solids load reduction based on lab
place, offline units can treat flows from 1 to 300 cfs (28.3 to generated performance curves for a gradation with an average
8495 Us). The pollutant removal capacity of the CDS system has particle size(d50) of 125 microns(um). For some regulatory
been proven in lab and field testing.
environments, CDS systems can also be designed to achieve an
80%annual solids load reduction based on an average particle
Operation Overview size 050) of 75 microns (um) or 50 microns (um).
Stormwater enters the diversion chamber where the diversion Water Quality Flow Rate Method
weir guides the flow into the unit's separation chamber and In some cases, regulations require that a specific treatment rate,
pollutants are removed from the flow. All flows up to the often referred to as the water quality design flow(WQQ), be
system's treatment design capacity enter the separation chamber treated. This WQQ represents the peak flow rate from either
and are treated. an event with a specific recurrence interval, e.g. the six-month
Swirl concentration and screen deflection force floatables and storm, or a water quality depth, e.g. 1/2-inch (13 mm) of
solids to the center of the separation chamber where 100%of rainfall.
floatables and neutrally buoyant debris larger than the screen The CDS is designed to treat all flows up to the WQQ. At influent
apertures are trapped. rates higher than the WQQ, the diversion weir will direct most
Stormwater then moves through the separation screen, under flow exceeding the WQQ around the separation chamber. This
the oil baffle and exits the system.The separation screen remains allows removal efficiency to remain relatively constant in the
clog free due to continuous deflection. separation chamber and eliminates the risk of washout during
bypass flows regardless of influent flow rates.
During the flow events exceeding the treatment design capacity,
the diversion weir bypasses excessive flows around the separation Treatment flow rates are defined as the rate at which the CDS
chamber, so captured pollutants are retained in the separation will remove a specific gradation of sediment at a specific removal
cylinder. efficiency. Therefore the treatment flow rate is variable, based
on the gradation and removal efficiency specified by the design
engineer.
GRATE INLET Rational Rainfall Method TM
CLEAN OUT (CAST IRON HOOD FOR
(REQUIRED) CURB INLET OPENING) Differences in local climate, topography and scale make every
j site hydraulically unique. It is important to take these factors into
DEFLECTION PAN,3 SIDED �°
consideration when estimating the long-term performance of
(GRATE INLET DESIGN) any Stormwater treatment System. The Rational Rainfall Method
CREST OF BYPASS WEIR
(ONE EACH SIDE) combines site-specific information with laboratory generated
p y
SEPARATION CYLINDER � ,� ""�`
performance data, and local historical precipitation records to
estimate removal efficiencies as accurately as possible.
INLET FLUME
Short duration rain gauge records from across the United States
and Canada were analyzed to determine the percent of the total
annual rainfall that fell at a range of intensities. US stations
D
depths were totaled every 15 minutes, or hourly, and recorded in
115
INLET 0.014ch increments. Depths were recorded hourly with 1-mm
(MULTIPLE PIPES POSSIBLE)
resolution at Canadian stations. One trend was consistent at
VNE
OIL BAFFLE
OUTLET �
all sites; the vast majority of precipitation fell at low intensities
TREATMENT SCREEN l � ,
and high intensity storms contributed relatively little to the total
t annual depth.
11 o
SEPARATION SLAB SUMP STORAGE
These intensities, along with the total drainage area and runoff
,,.
coefficientf r each specific site, are translatedi into flow ra
tes
WE
''' ''� using the Rational Rainfall Method. Since most sites are relatively
small and highly impervious, the Rational Rainfall Method is
appropriate. Based on the runoff flow rates calculated for each
intensity, operating rates within a proposed CDS system are
2
determined. Performance efficiency curve determined from full Two different gradations of silica sand material (UF Sediment
scale laboratory tests on defined sediment PSDs is applied to &OK-1 10)were used in the CDS performance evaluation. The
calculate solids removal efficiency. The relative removal efficiency particle size distributions(PSDs) of the test materials were
at each operating rate is added to produce a net annual pollutant analyzed using standard method "Gradation ASTM D-422
removal efficiency estimate. "Standard Test Method for Particle-Size Analysis of Soils" by a
Probabilistic Rational Method certified laboratory.
The Probabilistic Rational Method is a sizing program Contech OF Sediment is a mixture of three different products produced
developed to estimate a net annual sediment load reduction for by the U.S. Silica Company: "Sil-Co-Sil 106", "#1 DRY" and
a particular CDS model based on site size, site runoff coefficient, 1120/40 Oil Frac". Particle size distribution analysis shows that
regional rainfall intensity distribution, and anticipated pollutant the OF Sediment has a very fine gradation (d50 = 20 to 30 pm)
characteristics. covering a wide size range(Coefficient of Uniformity, C averaged
at 10.6). In comparison with the hypothetical TSS gradation
The Probabilistic Method is an extension of the Rational Method specified in the NJDEP(New Jersey Department of Environmental
used to estimate peak discharge rates generated by storm events Protection) and NJCAT(New Jersey Corporation for Advanced
of varying statistical return frequencies(e.g. 2-year storm event). Technology) protocol for lab testing,the OF Sediment covers a
Under the Rational Method, an adjustment factor is used to similar range of particle size but with a finer d50 (d50 for NJDEP
adjust the runoff coefficient estimated for the 10-year event, is approximately 50 pm) (NJDEP, 2003).
correlating a known hydrologic parameter with the target storm
event. The rainfall intensities vary depending on the return The OK-1 10 silica sand is a commercial product of U.S. Silica
frequency of the storm event under consideration. In general, Sand. The particle size distribution analysis of this material, also
these two frequency dependent parameters(rainfall intensity included in Figure 1, shows that 99.9%of the OK-1 10 sand is
and runoff coefficient) increase as the return frequency increases finer than 250 microns, with a mean particle size(d50)of 106
while the drainage area remains constant. microns. The PSDs for the test material are shown in Figure 1.
These intensities, along with the total drainage area and runoff 1mO ,;.rl,
coefficient for each specific site, are translated into flow rates 90,0 Sediment(Avg),
using the Rational Method. Since most sites are relatively small WO K I 10(Avg)
and highly impervious, the Rational Method is appropriate. Based 70, ° -
on the runoff flow rates calculated for each intensity, operating 60,011,
rates within a proposed CDS are determined. Performance
efficiency curve on defined sediment PSDs is applied to calculate °
_0�1
solids removal efficiency. The relative removal efficiency at each
20.0
XF
,
operating rate is added to produce a net annual pollutant
removal efficiency estimate.
Treatment Flow Rate 1 10 100 1000
The inlet throat area is sized to ensure that the WQQ passes Particl 11
through the separation chamber at a water surface elevation
equal to the crest of the diversion weir.The diversion weir Figure 1. Particle size distributions
bypasses excessive flows around the separation chamber, Tests were conducted to quantify the performance of a specific
thus preventing re-suspension or re-entrainment of previously
captured particles.
CDS unit(1.1 cfs(31.3-L/s) design capacity) at various flow rates,
o o
ranging from 1 /o up to 125/o of the treatment design capacity of
Hydraulic Capacity the unit, using the 2400 micron screen. All tests were conducted
The hydraulic capacity of a CDS system is determined by the with controlled influent concentrations of approximately 200
length and height of the diversion weir and by the maximum mg/L. Effluent samples were taken at equal time intervals
allowable head in the system.Typical configurations allow across the entire duration of each test run. These samples
hydraulic capacities of up to ten times the treatment flow rate. were then processed with a Dekaport Cone sample splitter to
The crest of the diversion weir may be lowered and the inlet obtain representative sub-samples for Suspended Sediment
throat may be widened to increase the capacity of the system Concentration (SSC)testing using ASTM D3977-97 "Standard
at a given water surface elevation. The unit is designed to meet Test Methods for Determining Sediment Concentration in Water
project specific hydraulic requirements. Samples", and particle size distribution analysis.
Performance Results and Modeling
Full-Scale Laboratory Test Results Based on the data from the University of Florida, a performance
model was developed for the CDS system. A regression analysis
A full-scale CDS system (Model CDS2020-5B)was tested at the was used to develop a fitting curve representative of the
facility of University of Florida, Gainesville, FL. This CDS unit was scattered data points at various design flow rates. This model,
evaluated under controlled laboratory conditions of influent flow which demonstrated good agreement with the laboratory data,
rate and addition of sediment. can then be used to predict CDS system performance with respect
3
to SSC removal for any particle size gradation, assuming the Maintenance
particles are inorganic sandy-silt. Figure 2 shows CDS predictive The CDS system should be inspected at regular intervals and
performance for two typical particle size gradations(NJCAT
gradation and OK-1 10 sand)as a function of operating rate. maintained when necessary to ensure optimum performance.
The rate at which the system collects pollutants will depend more
heavily on site activities than the size of the unit. For example,
unstable soils or heavy winter sanding will cause the grit chamber
a m�nY�mauwlrw��w mom��r
80"
"' w rv„w�w w�ww�,
"oil �� to fill more quickly but regular sweeping of paved surfaces will
slow accumulation.
. -------------------- ----..----._._.._._...._...
40 Inspection
� ���. Inspection is the key to effective maintenance and is easily
OK .�AT performed. Pollutant transport and deposition may vary from
,;,� �; year to year and regular inspections will help ensure that the
% % % % % 100 120% 1 % system is cleaned out at the appropriate time. At a minimum,
%Design FlowRate inspections should be performed twice per year(e.g. spring
and fall) however more frequent inspections may be necessary
Figure 2. CDS stormwater treatment predictive performance for in climates where winter sanding operations may lead to rapid
various particle gradations as a function of operating rate. accumulations, or in equipment washdown areas. Installations
Many regulatory jurisdictions set a performance standard for should also be inspected more frequently where excessive
hydrodynamic devices by stating that the devices shall be capable amounts of trash are expected.
of achieving an 80%removal efficiency for particles having a The visual inspection should ascertain that the system
mean particle size(d50) of 125 microns(e.g.Washington State components are in working order and that there are no
Department of Ecology—WASDOE -2008). The model can blockages or obstructions in the inlet and separation screen.
be used to calculate the expected performance of such a PSD The inspection should also quantify the accumulation of
(shown in Figure 3). The model indicates(Figure 4)that the CDS hydrocarbons, trash, and sediment in the system. Measuring
system with 2400 micron screen achieves approximately 80% pollutant accumulation can be done with a calibrated dipstick,
removal at the design (100%)flow rate, for this particle size tape measure or other measuring instrument. If absorbent
distribution (d50 = 125 pm). material is used for enhanced removal of hydrocarbons, the level
of discoloration of the sorbent material should also be identified
Particle Sze I strib i r
1 II ,,, .
rnmmmmmm msmmmm mmmm
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4
during inspection. It is useful and often required as part of an Cleaning
operating permit to keep a record of each inspection. A simple
form for doing so is provided. Cleaning of a CDS systems should be done during dry weather
conditions when no flow is entering the system. The use of a
Access to the CDS unit is typically achieved through two manhole vacuum truck is generally the most effective and convenient
access covers. One opening allows for inspection and cleanout method of removing pollutants from the system. Simply remove
of the separation chamber(cylinder and screen) and isolated the manhole covers and insert the vacuum hose into the sump.
sump. The other allows for inspection and cleanout of sediment The system should be completely drained down and the sump
captured and retained outside the screen. For deep units, a fully evacuated of sediment.The area outside the screen should
single manhole access point would allows both sump cleanout also be cleaned out if pollutant build-up exists in this area.
and access outside the screen.
In installations where the risk of petroleum spills is small, liquid
The CDS system should be cleaned when the level of sediment contaminants may not accumulate as quickly as sediment.
has reached 75%of capacity in the isolated sump or when an However, the system should be cleaned out immediately in the
appreciable level of hydrocarbons and trash has accumulated. event of an oil or gasoline spill. Motor oil and other hydrocarbons
If absorbent material is used, it should be replaced when that accumulate on a more routine basis should be removed
significant discoloration has occurred. Performance will not be when an appreciable layer has been captured.To remove these
impacted until 100%of the sump capacity is exceeded however pollutants, it may be preferable to use absorbent pads since they
it is recommended that the system be cleaned prior to that are usually less expensive to dispose than the oil/water emulsion
for easier removal of sediment. The level of sediment is easily that may be created by vacuuming the oily layer. Trash and debris
determined by measuring from finished grade down to the can be netted out to separate it from the other pollutants. The
top of the sediment pile. To avoid underestimating the level of screen should be cleaned to ensure it is free of trash and debris.
sediment in the chamber, the measuring device must be lowered Manhole covers should be securely seated following cleaning
to the top of the sediment pile carefully. Particles at the top of activities to prevent leakage of runoff into the system from above
the pile typically offer less resistance to the end of the rod than
consolidated particles toward the bottom of the pile. Once this and also to ensure that proper safety precautions have been
followed. Confined space entry procedures need to be followed
measurement is recorded, it should be compared to the as-built if physical access is required. Disposal of all material removed
drawing for the unit to determine weather the height of the from the CDS system should be done in accordance with local
sediment pile off the bottom of the sump floor exceeds 75%of
the total height of isolated sump. regulations. In many Jurisdictions, disposal of the sediments may
be handled in the same manner as the disposal of sediments
removed from catch basins or deep sump manholes. Check your
local regulations for specific requirements on disposal.
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CDS 1515 3 0.9 3.0 0.9 0.5 0.4
CDS2015 4 1.2 3.0 0.9 0.9 0.7
CDS2015 5 1.5 3.0 0.9 1.3 1.0
CDS2020 5 1.5 3.5 1.1 1.3 1.0
CDS2025 5 1.5 4.0 1.2 1.3 1.0
CDS3020 6 1.8 4.0 1.2 2.1 1.6
CDS3025 6 1.8 4.0 1.2 2.1 1.6
CDS3030 6 1.8 4.6 1.4 2.1 1.6
CDS3035 6 1.8 5.0 1.5 2.1 1.6
CDS4030 8 2.4 4.6 1.4 5.6 4.3
CDS4040 8 2.4 5.7 1.7 5.6 4.3
CDS4045 8 2.4 6.2 1.9 5.6 4.3
CDS5640 10 3.0 6.3 1.9 8.7 6.7
CDS5653 10 3.0 7.7 2.3 8.7 6.7
CDS5668 10 3.0 9.3 2.8 8.7 6.7
CDS5678 10 3.0 10.3 3.1 8.7 6.7
Table 1: CDS Maintenance Indicators and Sediment Storage Capacities
Note:To avoid underestimating the volume of sediment in the chamber, carefully lower the measuring device to the top of the
sediment pile. Finer silty particles at the top of the pile may be more difficult to feel with a measuring stick.These finer particles
typically offer less resistance to the end of the rod than larger particles toward the bottom of the pile.
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CDS Inspection ♦ Maintenance Log
CDS Model: Location:
Water Floatable Describe
Maintenance
Date depth to Layer Maintenance Comments
Personnel
sediment' Thickness' Performed
1. The water depth to sediment is determined by taking two measurements with a stadia rod: one measurement from the manhole opening to the
top of the sediment pile and the other from the manhole opening to the water surface. If the difference between these measurements is less
than the values listed in table 1 the system should be cleaned out. Note:to avoid underestimating the volume of sediment in the chamber,
the measuring device must be carefully lowered to the top of the sediment pile.
2. For optimum performance,the system should be cleaned out when the floating hydrocarbon layer accumulates to an appreciable thickness. In
the event of an oil spill,the system should be cleaned immediately.
7
SUPPORT
�� ' NTECHO
• Drawings and specifications are available at 1107 C
• Site-specific design support is available from our engineers. ENGINEERED SOLUTIONS
800-338-1122
www.ContechES.com
92017 Contech Engineered Solutions LLC,a QUIKRETE Company
Contech Engineered Solutions provides site solutions for the civil engineering industry. Contech's portfolio includes bridges,drainage,sanitary
sewer,earth stabilization and stormwater treatment products. For information on other Contech division offerings,visit www.ContechES.com or
call 800.338.1122
NOTHING IN THIS CATALOG SHOULD BE CONSTRUED AS A WARRANTY.APPLICATIONS SUGGESTED HEREIN ARE DESCRIBED ONLY TO HELP READERS MAKE THEIR OWN EVALUATIONS AND
DECISIONS,AND ARE NEITHER GUARANTEES NOR WARRANTIES OF SUITABILITY FOR ANY APPLICATION.CONTECH MAKES NO WARRANTY WHATSOEVER,EXPRESS OR IMPLIED,RELATED TO THE
APPLICATIONS,MATERIALS,COATINGS,OR PRODUCTS DISCUSSED HEREIN.ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND ALL IMPLIED WARRANTIES OF FITNESS FOR ANY PARTICULAR
PURPOSE ARE DISCLAIMED BY CONTECH.SEE CONTECH'S CONDITIONS OF SALE(AVAILABLE AT WWW.CONTECHES.COM/COS)FOR MORE INFORMATION.
The product(s)described may be protected by one or more of the following US patents: 5,322,629;5,624,576;5,707,527;5,759,415;5,788,848;5,985,157;6,027,639;6,350,374;6,406,218;
6,641,720;6,511,595;6,649,048;6,991,114;6,998,038;7,186,058;7,296,692;7,297,266; related foreign patents or other patents pending.
OW RECYCLED
cds manual 3/17 PDF tj
PAPER
StormiTfeche
13.1 ISOLATOR T'" ROW INSPECTION
Regular inspection and maintenance are essential to assure
a properly functioning stormwater system. Inspection is �'' N
easily accomplished through the manhole or optional
inspection ports of an Isolator Row. Please follow local
and OSHA rules for a confined space entry.
Inspection ports can allow inspection to be accomplished
completely from the surface without the need for a con-
fined space entry. Inspection ports provide visual access
to the system with the use of a flashlight. A stadia rod '?�t
may be inserted to determine the depth of sediment.
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J
If upon visual inspection it is found that sediment hasr
accumulated to an average depth exceeding 3"(76 mm), �
cleanout is required.
A StormTech Isolator Row should initially be inspected Lookingdown the Isolator Row.
immediately after completion of the site's construction.
While every effort should be made to prevent sediment
from entering the system during construction, it is during
this time that excess amounts of sediments are most
likely to enter any stormwater system. Inspection and "
maintenance, if necessary, should be performed prior
to passing responsibility over to the site's owner. Once Al,
i;
in normal service, a StormTech Isolator Row should be
inspected bi-annually until an understanding of the sites
characteristics is developed. The site's maintenance
manager can then revise the inspection schedule based `01 MI ,
on experience or local requirements.
13.2 ISOLATOR ROW MAINTENANCE 11
JetVac maintenance is recommended if sediment has Or �
been collected to an average depth of 3" (76 mm) inside
the Isolator Row. More frequent maintenance may be
required to maintain minimum flow rates through the A typical JetVac truck. (This is not a StormTech product.)
Isolator Row. 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 ; y 0
»u
All
«rurmsnd+u»" ���iuurM�jutr�rNw'f'l��f rrrioumiiJJuYKtnrrrr!�'(��r ,,.
retrieved, a wave of suspended sediments is flushed back
into the manhole for vacuuming. Most sewer and pipe
r ,r
maintenance companies have vacuum/JetVac combi-
nation vehicles. Fixed nozzles designed for culverts or
g pip g p g
large diameter pipe cleaning are referable. Rear facing
jets with an effective spread of at least 45" (1143 mm) �� � ��'"% ������!'�;'
17
are best. The JetVac process shall only be performed
on StormTech Rows that have AASHTO class 1 woven
geotextile over their foundation stone.
r
v
rrrr�
V
i
Examples of culvert cleaning nozzles appropriate for Isolator Row
maintenance. (These are not StormTech products.)
Call StormTech at 860.529.8188 or 888.892.2694 or visit our website at www.stormtech.com for technical and product information. 21
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STORMTECH ISOLATOR" ROW- STEP-BY-STEP 13.3 ECCENTRIC PIPE HEADER INSPECTION
MAINTENANCE PROCEDURES Theses guidelines do not supercede a pipe manufac-
turer's recommended I&M procedures. Consult with the
Step 1) Inspect Isolator Row for sediment manufacturer of the pipe header system for specific I&M
procedures. Inspection of the header system should
A) Inspection ports (if present) be carried out quarterly. On sites which generate higher
i. Remove lid from floor box frame levels of sediment more frequent inspections may be
ii. Remove cap from inspection riser necessary. Headers may be accessed through risers,
access ports or manholes. Measurement of sediment
iii. Using a flashlight and stadia rod, measure may be taken with a stadia rod or similar device. Clean-
depth of sediment out of sediment should occur when the sediment volume
iv. If sediment is at, or above, 3" (76 mm) has reduced the storage area by 25% or the depth
depth proceed to Step 2. If not proceed of sediment has reached approximately 25% of the
to Step 3. diameter of the structure.
B) All Isolator Rows 13.4 ECCENTRIC PIPE MANIFOLD MAINTENANCE
i. Remove cover from manhole at upstream Cleanout of accumulated material should be accom-
end of Isolator Row plished by vacuum pumping the material from the head-
ii. Using a flashlight, inspect down Isolator er. Cleanout should be accomplished during dry weath-
Row through outlet pipe er. Care should be taken to avoid flushing sediments out
1. Follow OSHA regulations for confined through the outlet pipes and into the chamber rows.
space entry if entering manhole Eccentric Header Step-by-Step Maintenance
2. Mirrors on poles or cameras may be Procedures
used to avoid a confined space entry 1. Locate manholes connected to the manifold system
iii. If sediment is at or above the lower row of 2. Remove grates or covers
sidewall holes [approximately 3" (76 mm)] 3. Using a stadia rod, measure the depth of sediment
proceed to Step 2. If not proceed to Step 3. 4. If sediment is at a depth of about 25% pipe volume
Step 2)Clean out Isolator Row using the JetVac process or 25% pipe diameter proceed to step 5. If not
proceed to step 6.
A)A fixed culvert cleaning nozzle with rear 5. Vacuum pump the sediment. Do not flush sediment
facing nozzle spread of 45" (1143 mm) or out inlet pipes.
more is preferable 6. Replace grates and covers
B)Apply multiple passes of JetVac until back- 7. Record depth and date and schedule next inspection
flush water is clean
C)Vacuum manhole sump as required during
Figure 21 —Eccentric Manifold Maintenance
jetting 1 2 6
Step 3)Replace all caps, lids and covers
Step 4) Inspect and clean catch basins and manholes
upstream of the StormTech system following local
guidelines.
3,4,5
Figure 20—StormTech Isolator Row(not to scale)
1)B) 1)A)
2
Please contact StormTech's Technical Services
Department at 888-892-2894 for a spreadsheet to
-- ' estimate cleaning intervals.
22 Call StormTech at 860.529.8188 or 888.892.2694 or visit our website at www.stormtech.com for technical and product information.
Operations and Maintenance Plan I Merrimack College, North Andover, MA
Section G: Maintenance Agreement
Operationsi I Merrimack College, North Andover, MA
G Maintenance Agreement
The Owner(s) hereby agree(s)to that they have read and understood this Operations and
Maintenance Plan and for the length of their ownership will follow and conduct all
inspection and maintenance procedures as stated in Sections A-F at the recommended
intervals, or as could be deemed necessary by any reasonable party,whichever comes first.
..................................................................................................................................................... Fr. Bryan Kerns,O.S.A.
l it aiin Kerins(Dec 1., 024 1.2:1. IEs T) y
Signature Printed Name
315 Turnpike Street
North Andover, MA 01845
Address Telephone Number
Dec 16,2024
Date
G-1 Maintenance Agreement