HomeMy WebLinkAboutStormwater Operation and Maintenance Plan - 268 Stevens St DiPrete Engineering
Stormwater System Operation & Maintenance Plan
Stevens Street Multi-Family
Located in Hyannis, MA
Applicant: Housing Assistance Corporation of Cape Cod
11-29-2023
Revised: 03/15/2024
Stevens Street Multi-Family
Table of Contents
Operation & Maintenance Plan Overview 1
Stormwater System Owner / Party Responsible for O&M 2
Public Safety 3
Stormwater System Plan 5
Inspections & Maintenance 7
Estimated Inspections & Maintenance Budget 10
Appendix A – Inspection Schedule & Maintenance Checklists 11
Appendix B –Sample Stormwater Facility Maintenance Agreement 24
Appendix C – Stormcrete Operation and Maintenance Manual 27
Stevens Street Multi-Family
Operation & Maintenance Plan Overview
An essential component of a successful Stormwater System (SS) is the ongoing Operation and
Maintenance (O&M) of the various components of the stormwater drainage, control, and conveyance
systems. These components include swales, pipes, catch basins, and treatment/ control devices are
commonly referred to as Best Management Practices (BMPs). Failure to provide effective maintenance
can reduce the hydraulic capacity and the pollutant removal efficiency of stormwater practices.
Many people expect that stormwater facilities will continue to function correctly forever. However, it is
inevitable that deterioration of the stormwater system will occur once it becomes operational. The
question is not whether stormwater system maintenance is necessary but how often.
This plan has been developed to proactively address operations and maintenance to minimize potential
problems and maximize potential stormwater runoff treatment and management. Ongoing inspections
and maintenance will extend the service life of the Best Management Practices.
This plan addresses:
1.Stormwater management system(s) owners;
2.The party or parties responsible for operation and maintenance, including how future property
owners will be notified of the presence of the stormwater management system and the
requirement for proper operation and maintenance;
3.A description and delineation of public safety features;
4.The routine (scheduled) and non-routine (corrective) maintenance tasks for each BMP to be
undertaken after construction is complete and a schedule for implementing those tasks;
5.A plan that is drawn to scale and shows the location of all stormwater BMPs in each treatment
train along with the discharge point;
6.An estimated operation and maintenance budget; and
7.Funding source for operation and maintenance activities and equipment.
A major contributor to unmaintained stormwater facilities is a lack of clear ownership and responsibility
definition. In order for an inspection and maintenance program to be effective, the roles for each
responsibility must be clearly defined prior to construction of a system. This can be accomplished with a
maintenance agreement between the site owners and the responsible authority.
This report is suitable for recording as an attachment to a maintenance agreement between the site
owner and the responsible authority. A copy of a sample agreement is attached to this report as
Appendix B.
1
Stevens Street Multi-Family
Stormwater System Owner / Party Responsible for O&M
Stormwater BMPs are maintained during construction by the site contractor as identified in the
Stormwater Pollution Prevention Plan (SWPPP) for the site. A copy of the SWPPP is required to be kept
on site during construction. The SWPPP requires maintenance and inspection of the BMPs during the
construction phase of project and requires a log be kept of these activities. Once construction is
complete and the contractor's warranty period is elapsed, the contractor must obtain the signature of
the stormwater system's owner releasing the contractor from his maintenance and inspection
responsibilities. A copy of this release of contractor’s responsibility must be attached to this document.
The Owners Association will be owner of the stormwater system. Upon completion of construction, and
creation of the Owners Association, their legal name along with mailing and emergency contact
information must be added below.
Owner:
Mailing Address:
Emergency Contact Name:
Phone:
Transfer of Ownership
In the event that the owner of any property included in the Owners Association changes, the current
owner (grantor) must provide a copy of this document to the new owner (grantee). In addition, the
Owners Association must provide all new members with a copy of this document. The new owner must
notify the Massachusetts Department of Environmental Protection (MassDEP) of the change of
ownership and provide a signed updated Operations and Maintenance Plan to MassDEP.
The Stormwater System Owner is the Party Responsible for the ongoing O&M of the system.
The two key components to adequately maintain the stormwater infrastructure are:
1.Performance of periodic and scheduled inspections
2.Performance of scheduled maintenance
The actual operation and maintenance of the system may be performed by a third party designated by
the owner. If the owner contracts with a third party for O&M the name, address, and emergency
contact information must be added below, and updated if the third party designee changes.
Name:
Mailing Address:
Emergency Contact Name:
Phone:
2
Stevens Street Multi-Family
Public Safety
Public safety was a critical factor in designing the stormwater system. Public safety features included in
this design are:
Accessibility to Stormwater BMPs
Straightforward Subsurface Repairs and Quick Slab Replacements if Needed
Winter & Non-Winter Maintenance
Accessibility to Stormwater BMPs
As shown on the site plans, the Stormcrete Precast Porous Concrete Slabs are located in the parking
areas of the parking lot and accessible from the drive aisles. Prior to regular maintenance, the BMP area
must be zoned off with traffic cones and must be performed during off-peak hours.
Winter Maintenance
The Stormcrete Modular Precast Porous Concrete Stormwater System Operations and Maintenance
Manual can be found in appendix A of this report and must be followed. The following tasks must be
performed to protect public safety during the winter season:
Roadways to be salted/ plowed in accordance with applicable Town of Barnstable and
MassDOT/ MassDEP requirements;
For all parking areas, if possible, avoid applying sand to Stormcrete Surfaces
Snow can be removed from Stormcrete using conventional plow blades equipped with shoes,
although wherever possible plows should be equipped with a plastic or rubber cutting edge.
Snow within pores of Stormcrete can make them appear more snow covered than standard
impervious pavement. Stormcrete should not be “over worked” or scraped.
When accumulated sand and salt is observed on Stormcrete panels, vacuum cleaning is
recommended to minimize the potential for clogging and preserve the longevity of the product.
Inspect the open and closed drainage networks adjacent to the snow stockpiles to ensure they
are free of clogging and debris;
Inspect roadways and drainage structures post-storm event to alleviate any signs of icing or
damming.
If any of the Stormcrete slabs become clogged or otherwise fails beyond the point of
rejuvenation, it/they must be replaced.
3
Stevens Street Multi-Family
Non-Winter Maintenance
The Stormcrete Modular Precast Porous Concrete Stormwater System Operations and Maintenance
Manual can be found in appendix A of this report and must be followed. The following tasks must be
performed to protect public safety during the non-winter seasons:
Roadways to be swept in accordance with applicable Town of Barnstable and MassDOT/
MassDEP requirements;
Vacuuming of Stormcrete areas must be performed a minimum of 2 times per year using a
regenerative air vacuum sweeper, high-efficiency vacuum only sweepers or a Stormwater SUV.
A high-powered backpack blower or approved equal can be used for regular maintenance.
A manufactured Porous Rehabilitation Device or Focused Power Washer must be used when
unclogging plugged areas within the Stormcrete surfaces.
If any of the Stormcrete slabs become clogged or otherwise fails beyond the point of
rejuvenation, it/they must be replaced.
The stormwater management systems must be inspected and maintained in accordance with
the enclosed Operations & Maintenance Plan.
Particular care must be taken in the operation and maintenance of these features.
4
Stevens Street Multi-Family
Stormwater System Plan
A plan identifying each component of the stormwater system is included on the following page.
5
VANINFILTRATION
SYSTEM E
LEACHING CATCH BASINS
INFILTRATION
SYSTEM B
INFILTRATION
SYSTEM C
INFILTRATION
SYSTEM D
UNDERGROUND
INFILTRATION
SYSTEM
INFILTRATION
SYSTEM A
DRAINAGE
NETWORK
(TYP)
LEACHING CATCH BASIN
INFILTRATION
POND
SEDIMENT
FOREBAY STEVENS STREET(VARIABLE W
IDTH PUBL
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IGHT OF WAY)
MULTI-FAMILY
BUILDING
SITE
MAP 308 LOT 17
1.49 ACRES
MITCHELLS WAY
(VARIABLE WIDTH PUBLIC RIGHT O
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W
A
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)NORTH STREET(VARIABLE WIDTH PUBLIC RIGHT OF
WAY)DiPrete Engineering0 20' 40' 80'
SCALE: 1"=40'Two Stafford Court Cranston, RI 02920tel 401-943-1000 fax 401-464-6006 www.diprete-eng.comBoston Providence Newportz:\demain\projects\3300-001 stevens street 268\autocad drawings\3300-001-plan.dwg Plotted: 3/15/20241Operations & Maintenance OF 1SHEETPREPARED FOR:DE Job No: 0XXX-XXX Copyright 2024 by DiPrete Engineering Associates, Inc.40 WEST MAIN STREET, HYANNIS, MASSACHUSETTS 02601HYANNIS, MASSACHUSETTS5teXens 5treet MWNtiÄ(aOiN[*oWsinI #ssistance %orporation oH %ape %oF3-14-2024DATE:6
Stevens Street Multi-Family
Inspections & Maintenance
Inspections must be performed on a regular basis and scheduled based on the BMP type and
configuration. It is not mandatory that all inspectors be trained engineers, but they must have some
knowledge or experience with stormwater systems and in general, trained stormwater engineers should
direct the inspectors. Follow-up inspections by registered professional engineers must be performed
where a routine inspection has revealed a question of structural or hydraulic integrity affecting public
safety.
Not all inspections can be conducted by direct human observation. For subsurface systems, video
equipment may be required. There may be cases where other specialized equipment is necessary. The
inspection program must be tailored to address the operational characteristics of the system.
The inspection process must document observations made in the field and must cover structural
conditions, hydraulic operational conditions, evidence of vandalism, condition of vegetation, occurrence
of obstructions, unsafe conditions, and build-up of trash, sediments and pollutants.
Maintenance of the stormwater management system is essential and can be divided into two types,
scheduled and corrective.
Scheduled maintenance tasks are those that are typically accomplished on a regular basis and can
generally be scheduled without referencing inspection reports. These items consist of such things as
vegetation maintenance (such as mowing) and trash and debris removal. These tasks are required at
well-defined time intervals and are a requirement for all stormwater structural facilities.
Corrective maintenance tasks consist of items such as sediment removal, stream bank stabilization, and
outlet structure repairs that are done on an as-needed basis. These tasks are typically scheduled based
on inspection results or in response to complaints.
Since specialized equipment may be required, some maintenance tasks can be effectively handled on a
contract basis with an outside entity specializing in that field. In addition, some maintenance may also
require a formal design and bid process to accomplish the work.
Appendix A provides an "Inspection Schedule & Maintenance Checklist" for the stormwater system
components on this site. Completed checklists must be maintained as an ongoing record of inspections
for each component of the stormwater system.
In addition to the maintenance of the stormwater system, maintenance of other site improvements can
significantly enhance the ability for the BMPs to function as designed. Several of these have been listed
below, along with the recommended maintenance.
7
Stevens Street Multi-Family
Lawn, Garden and Landscape Management
Lawns should be cut no shorter than 1-1/2" in the spring and fall to stimulate root growth, and
no shorter than 2 to 3 inches throughout the summer.
Infiltration ponds should be mowed at least twice per year.
Fertilize no more than twice per year, once in May-June and once in September-October.
Avoid spreading fertilizer on impervious surfaces.
Weeds should be dug or pulled out. Large areas of weeds can be removed by covering with
large plastic sheet(s) for a few days.
Chemical pesticides should be used as a last resort. A healthy lawn is naturally disease resistant.
o Visible insects can be removed by hand, by spraying with water, or even vacuum
cleaning.
o Store bought traps, specific for a species, can be used.
o Slugs and other soft bodied insects can be eliminated using diatomaceous earth.
o Plants infected with bacteria and fungi should be removed and disposed of.
o Beneficial organisms should be maintained on the property and should be encouraged/
attracted to the property. Homeowners and property facility maintenance personal
should become familiar with beneficial organisms.
Irrigation should be minimal if required at all. Most lawns do not require watering and will
become dormant during dry periods.
o Established lawns require no more than one inch of water per week.
o Lawn areas should be watered before 9am to avoid evaporation.
Road and Parking Area Management
Street and Parking Lot Sweeping
All street and parking areas on site must be swept a minimum of 2 times per year.
Vacuuming of Stormcrete areas must be performed a minimum of 2 times per year using a
regenerative air vacuum sweeper, high-efficiency vacuum only sweepers or a Stormwater SUV.
A high-powered backpack blower or approved equal can be used for regular maintenance.
Deicing:
Salt storage areas must be completely covered and located on an impervious surface.
Runoff must be contained in appropriate areas.
See The Guidelines on Road Salt Storage offered by MassDEP for more detailed definitions and
best management practices. The Guidelines on Road Salt Storage can be found online at:
https://www.mass.gov/guides/guidelines-on-road-salt-storage
8
Stevens Street Multi-Family
Sealants:
Only asphalt-based sealants are permitted, no coal-tar based asphalt sealants can be used on
site.
General Snow Removal:
Snow must not be dumped in any water body including rivers, reservoirs, ponds, lakes, wetlands,
bays, or the ocean.
Avoid disposing of snow on top of storm drain catch basins or stormwater drainage swales or
ditches.
Snow must be stored in upland areas, not in or adjacent to water bodies or wetlands. Snow must
be stored in a location that will allow snow melt and enter the onsite drainage system so it can
be treated by onsite BMPs.
Stormcrete Snow Removal:
Conventional plow blades equipped with wearing shoes can be used for snow removal. It is
recommended that the plow passes be made at a 45-degree angle to the joint slabs with no ack
dragging.
Snow within the pores will appear to be more snow covered than standard pavement and should
not be “overworked” by plows or shovel.
Solid Waste Containment
Trash and recycling receptacles must be located onsite for all commercial areas.
Reference; Additional information relating to operation and maintenance of specific BMPs can be found
in the Massachusetts Stormwater Handbook, particularly Volume 2, Chapter 2.
(https://www.mass.gov/files/documents/2016/08/qi/v2c2.pdf)
9
Stevens Street Multi-Family
Estimated Inspections & Maintenance Budget
It is important to be able to budget for the O&M costs associated with the stormwater system. To assist
the owner in budgeting, below is an estimate of the costs that may be incurred in maintaining the
system. The costs have been estimated on a Yearly basis.
Underground Infiltration System:
For a 25 year finance period, Infiltration Structures cost approximately $1,277.77 per acre of tributary
area per year. The site contains approximately 0.402 acres of area flowing to the Underground
Infiltration System. This equates to an approximate cost of $514 per year to maintain the infiltration
structures.
Stormcrete Modular Precast Porous Concrete:
For damaged areas that require replacement, Stormcrete installation costs approximately $15 per sq.ft.
A maintenance budget for this system can vary and will be determined following an agreed and
accepted maintenance contract with Stormwater Compliance, LLC. On average, the annual cost to
provide Stormwater Management Services is approximately $0.08 per sq.ft. of Stormcrete. This equates
to an approximate cost of $464 per year to maintain the systems.
Based on the costs outlined above, the stormwater system will cost approximately $978 per year to
maintain. This is only an estimate and subject to change following a signed maintenance contract. Note
that Stormwater Compliance, LLC offers a 1-year warranty and the first 1-year maintenance is included
for free when committing to a long term (3-5 year) maintenance contract.
These costs are the responsibility of the stormwater system owner. Funding for the costs will be
provided by the owner.
Reference; Maintenance costs are based on information provided by Horsely Witten during the January
19, 2011 Stormwater Manual Training.
(http://www.dem.ri.gov/programs/benviron/water/permits/ripdes/stwater/t4guide/slides/sess210.ppt)
10
Stevens Street Multi-Family
Appendix A – Inspection Schedule & Maintenance Checklists
11
Stormcrete Modular Precast Porous Concrete
Operation, Maintenance, and Management
Inspection Checklist
Project: Date:
Location: Time:
Site Status: Inspector:
Notes:
• Beyond inspection frequency noted in parenthesis, i.e. (quarterly), inspections shall be
completed after storms equal to or greater than the 1-year 24-hour Type III storm event
(2.7” of rain fall)
• All Checklist Maintenance items are MANDATORY.
• During inspections, if maintenance items are found not to be applicable, note as N/A in
comments
• All removed sediments shall be disposed at an approved and permitted location.
• All hazardous debris removed shall be disposed of in accordance with state and federal
regulations by a properly licensed contractor
MAINTENANCE ITEM SATISFACTORY
(YES/NO) COMMENTS
1. Sediment and Debris Cleanout (Monthly or Manufacturer’s
Recommendation)
Contributing area free of sediment and
debris. Voids free of any fine material
Contributing area stabilized and mown, with
grass clippings removed
Inspect for evidence of run-on from
perimeter unpaved areas or nearby erosion
No signs of clogging or debris (e.g., standing
water, leaves, trash, etc.)
Surface does not require vacuuming
2. Dewatering (Monthly or Manufacturer’s Recommendation)
Permeable pavement dewaters between
storms
3. Surface Repairs (Annually or Manufacturer’s Recommendation)
No evidence of surface deficiencies (i.e.
raveling, spalling, cracking, etc.)
12
Stormcrete Modular Precast Porous Concrete
Operation, Maintenance, and Management
Inspection Checklist
Project: Date:
Location: Time:
Site Status: Inspector:
Surface (top and base course) does not need
to be replaced
4. Vacuum Sweeping or Hosing (Semi-Annually)
Semi-Annual vacuum sweeping or hosing per
manufacturer
5. Miscellaneous
Minimize use of sand and salt within
proximity of Stormcrete in winter months
Post signs identifying permeable pavement
Attached rollers to the bottoms of
snowplows to prevent them from catching
on the edges of grass pavers and some
paving stones
13
Stormcrete Modular Precast Porous Concrete
Operation, Maintenance, and Management
Inspection Checklist
Project: Date:
Location: Time:
Site Status: Inspector:
COMMENTS:
ACTIONS TO BE TAKEN:
14
Drainage Structures
(Catch Basins, Deep Sump Catch Basins, Manholes, etc.)
Operation, Maintenance, and Management Inspection
Checklist
Project:Date:
Location:Time:
Site Status:Inspector:
Notes:
Beyond inspection frequency noted in parentheses, i.e (quarterly), inspections shall be
completed as follows:
o At minimum 4 times per year
o After storms equal to or greater than the 1-year 24-hour Type III storm event
(2.7” of rain fall)
o Whenever the depth of deposits is greater than or equal to one half the depth
from the bottom of the invert of the lowest pipe in the basin.
o At the end of the foliage and snow-removal season.
All Checklist Maintenance items are MANDATORY.
During inspections, if maintenance items are found not to be applicable, note as N/A in
comments
All removed sediments shall be disposed at an approved location or other facility
permitted by MassDEP.
All hazardous debris removed shall be disposed of in accordance with state and federal
regulations (Hazardous waste Regulations, 310 CMR 30.000) by a properly licensed contr
actor
MAINTENANCE ITEM
SATISFACTORY
(YES/NO)COMMENTS
Inspect drainage structures for damage
Use a vacuum truck or other means to
clean out any sediment or debris present in
any drainage structure or whenever
sediments reach ½ of the sump depth,
whichever comes first. Police detail may be
necessary to safeguard workers if catch
basin is deep.
Inspect drainage structures for debris and
remove as necessary according to MassDEP
regulations.
15
Drainage Structures
(Catch Basins, Deep Sump Catch Basins, Manholes, etc.)
Operation, Maintenance, and Management Inspection
Checklist
Project:Date:
Location:Time:
Site Status:Inspector:
16
Drainage Structures
(Catch Basins, Deep Sump Catch Basins, Manholes, etc.)
Operation, Maintenance, and Management Inspection
Checklist
Project:Date:
Location:Time:
Site Status:Inspector:
COMMENTS:
ACTIONS TO BE TAKEN:
17
Leaching Structures
Operation, Maintenance, and Management
Inspection Checklist
Project:Date:
Location:Time:
Site Status:Inspector:
Notes:
Beyond inspection frequency noted in parenthesis, i.e. (quarterly), inspections shall be
completed after storms equal to or greater than the 1-year 24-hour Type III storm event
(2.7” of rain fall)
All Checklist Maintenance items are MANDATORY.
During inspections, if maintenance items are found not to be applicable, note as N/A in
comments
All removed sediments shall be disposed at an approved and permitted location.
All hazardous debris removed shall be disposed of in accordance with state and federal
regulations by a properly licensed contractor
Repair or complete replacement to Leaching structure is required if system fails to
infiltrate fully within 48 hours.
All removed sediments shall be disposed at an approved and permitted location in
accordance with all applicable local, state, and federal laws and regulations including
M.G.L.c. 21C and 310 CMR 30.00.
All hazardous debris removed shall be disposed at an approved and permitted location
accordance with all applicable local, state, and federal laws and regulations including
M.G.L.c. 21C and 310 CMR 30.00 by a properly licensed contractor.
MAINTENANCE ITEM
SATISFACTORY
(YES/NO)
COMMENTS
Semi-annually inspect drainage structures
for damage
Structures clear of debris/ floatables or
accumulated sediment.
Inflow pipes clear of debris/ floatables
Structures dewaters between storms
Structure shall be cleaned/repaired when draw
down exceeds 36 hours.
18
Leaching Structures
Operation, Maintenance, and Management
Inspection Checklist
Project:Date:
Location:Time:
Site Status:Inspector:
No evidence of disrepair (presence of
structural damage)
Annual inspection for damage
Annual inspection for hydrocarbon build-up
and removal if detected.
Annual inspection for sediment
accumulation in the facility
(presence of structural
Surface of aggregate clean
Top layer of stone does not need
replacement
Chamber does not need rehabilitation
(presence of structural damage)
19
Leaching Structures
Operation, Maintenance, and Management
Inspection Checklist
Project:Date:
Location:Time:
Site Status:Inspector:
COMMENTS:
ACTIONS TO BE TAKEN:
20
Underground System
Operation, Maintenance, and Management
Inspection Checklist
Project:Date:
Location:Time:
Site Status:Inspector:
Notes:
Beyond inspection frequency noted in parenthesis, i.e. (quarterly), inspections shall be
completed after storms equal to or greater than the 1-year 24-hour Type III storm event
(2.7” of rain fall)
All Checklist Maintenance items are MANDATORY.
During inspections, if maintenance items are found not to be applicable, note as N/A in
comments
All removed sediments shall be disposed at an approved and permitted location.
All hazardous debris removed shall be disposed of in accordance with state and federal
regulations by a properly licensed contractor
Repair or complete replacement to Underground Infiltration System Practice is required
if system fails to infiltrate fully within 48 hours.
Inspection Ports are provided over each row of the chambers for inspections. Manholes
are provided at one end of each isolator row for access and maintenance.
All removed sediments shall be disposed at an approved and permitted location in
accordance with all applicable local, state, and federal laws and regulations including
M.G.L.c. 21C and 310 CMR 30.00.
All hazardous debris removed shall be disposed at an approved and permitted location
accordance with all applicable local, state, and federal laws and regulations including
M.G.L.c. 21C and 310 CMR 30.00 by a properly licensed contractor.
MAINTENANCE ITEM
SATISFACTORY
(YES/NO)
COMMENTS
1. Debris Cleanout (Quarterly)
The isolator row chamber(s) clear of debris/
floatables or accumulated sediment.
Inflow pipes clear of debris/ floatables
Overflow spillway clear of debris/ floatables
Inlet area clear of debris/ floatables
21
Underground System
Operation, Maintenance, and Management
Inspection Checklist
Project:Date:
Location:Time:
Site Status:Inspector:
2. Dewatering (Annual)
Chamber dewaters between storms
Outlet devices shall be cleaned/repaired when
draw down exceeds 36 hours.
3. Sediment Cleanout of Chamber (Annual)
No evidence of sedimentation in chamber
Sedimentation accumulation doesn’t yet
require cleanout
Sediment Shall be removed from the
system when sediment volume exceeds
10% of the total vault volume
Remove sediments by hydro-jetting of
sediments and vactoring (vacuuming)
4. Inlets (Quarterly)
Good condition
No evidence of disrepair (presence of
structural damage)
5. Aggregate Repairs (Annual)
Annual inspection for damage
Annual inspection for hydrocarbon build-up
and removal if detected.
Annual inspection for sediment
accumulation in the facility
(presence of structural
Surface of aggregate clean
Top layer of stone does not need
replacement
Chamber does not need rehabilitation
(presence of structural damage)
22
Underground System
Operation, Maintenance, and Management
Inspection Checklist
Project:Date:
Location:Time:
Site Status:Inspector:
COMMENTS:
ACTIONS TO BE TAKEN:
23
Sediment Forebay
Operation, Maintenance, and Management
Inspection Checklist
Project:Date:
Location:Time:
Site Status:Inspector:
Notes:
Beyond inspection frequency noted in parenthesis, i.e. (monthly), inspections shall be
completed after storms equal to or greater than the 1-year 24-hour Type III storm event
(2.7” of rain fall)
All Checklist Maintenance items are MANDATORY.
During inspections, if maintenance items are found not to be applicable, note as N/A in
comments
All removed sediments shall be disposed at an approved location or other facility
permitted by MassDEP.
All hazardous debris removed shall be disposed of in accordance with state and federal
regulations (Hazardous waste Regulations, 310 CMR 30.000) by a properly licensed contrac
tor.
Clean Sediment Forebay when sediment depth exceeds 2 feet
MAINTENANCE ITEM
SATISFACTORY
(YES/NO)COMMENTS
1. Debris Cleanout (Monthly)
The sediment forebay and sediment trap
isolation chamber clear of debris or
accumulated sediment.
Inflow pipes / inlet area clear of debris
Outflow pipes / outlet area clear of debris
Overflow Weir / outlet area clear of debris
2. Sedimentation (Monthly)
Obvious trapping of sediment
Greater than 50% of storage volume
remaining. If less than 50% of storage volume
remaining, sediments to be removed and
disposed of. (see notes at end of Forebay
Checklist)
24
Sediment Forebay
Operation, Maintenance, and Management
Inspection Checklist
Project:Date:
Location:Time:
Site Status:Inspector:
3. Vegetation (Monthly)
Vegetation within sediment forebay to be
limited to 6” in height. When mowing grasses,
keep the grass height no greater than 6 inches.
Set mower blades no lower than 3 to 4 inches.
4. Embankments (Monthly)
Displacement of stone check damn/ weir, rip
rap/failure of erosion protective measures
around inlet. Additional measures must be
installed immediately including (but not
limited to) larger riprap, reinforcement mats or
other method approved by suitably qualified
engineer. Fabric or wire may be required.
Evidence of rilling and gullying. Repair as
needed (reseeding or resodding. When
reseeding, incorporate practices such as
hydroseeding with a tackifier blanket, or
similar practice to ensure that no scour
occurs).
Seeps/leaks on downstream face
Slope protection or riprap failure
Slopes stabilized with vegetation, slope
protection, riprap, etc (side sloped of sediment
forebays no steeper than 3:1)
25
Sediment Forebay
Operation, Maintenance, and Management
Inspection Checklist
Project:Date:
Location:Time:
Site Status:Inspector:
COMMENTS:
26
Sediment Forebay
Operation, Maintenance, and Management
Inspection Checklist
Project:Date:
Location:Time:
Site Status:Inspector:
ACTIONS TO BE TAKEN:
27
Infiltration Pond
Operation, Maintenance, and Management
Inspection Checklist
Project:Date:
Location:Time:
Site Status:Inspector:
Notes:
Beyond inspection frequency noted in parenthesis, i.e. (semi-annually), inspections shall
be completed:
o after storms equal to or greater than the 1-year 24-hour Type III storm event
(2.7” of rain fall)
o after every storm during the first 3 months of operating (noting how long water
remains standing in the basin after a storm
o standing water within the basin 48 to 72 hours after a storm indicates that the
infiltration capacity may have been overestimated)
o twice a year thereafter and when there are discharges through the high outlet.
All Checklist Maintenance items are MANDATORY.
During inspections, if maintenance items are found not to be applicable, note as N/A in
comments
All removed sediments shall be disposed at an approved location or other facility
permitted by MassDEP.
All hazardous debris removed shall be disposed of in accordance with state and federal
regulations (Hazardous waste Regulations, 310 CMR 30.000) by a properly licensed contr
actor
Sediment shall be removed from stormwater basins when the sediment volume exceeds
10% of the total basin volume. Sediment shall be disposed of in an acceptable manner at
an approved and permitted location.
Infiltration Ponds Only: When infiltration rates decrease below design infiltration rates,
remove accumulated surface sediments and rototill pond bottom. Revegetate bottom
of infiltration pond as needed.
Mow the buffer area, side slopes and basin bottom grassed floor; rake if stone bottom;
remove trash grass clipping and accumulated organic matter semi-annually.
Important items to check during the inspection include:
o Signs of differential settlement
o Cracking.
o Erosion.
o Leakage in the embankments
o Tree growth on the embankments.
o Condition of riprap.
o Sediment accumulation and
o The health of the turf.
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Infiltration Pond
Operation, Maintenance, and Management
Inspection Checklist
Project:Date:
Location:Time:
Site Status:Inspector:
MAINTENANCE ITEM SATISFACTORY
(YES/NO)
COMMENTS
1.Embankment and Emergency Spillway (Semi-Annually)
Vegetation and ground cover adequate. Area
free of accumulated organic matter.
Embankment erosion or tree growth.
The area at the top of the basin must provide
unimpeded vehicular access around the
entire basin perimeter and shall be no less
than 12 feet.
Signs of differential settlement.
The health of the vegetation.
Animal burrows.
Unauthorized planting.
Cracking, bulging or sliding of dam.
Upstream face
Downstream face
At or beyond toe
Downstream
Upstream
Emergency spillway
Basin, toe & chimney drains clear and
functioning.
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Infiltration Pond
Operation, Maintenance, and Management
Inspection Checklist
Project:Date:
Location:Time:
Site Status:Inspector:
Seeps/leaks on downstream face.
Slope protection or riprap failure.
Vertical/horizontal alignment of top of dam
“As-Built”.
Emergency Spillway clear of obstructions and
debris.
2. Riser and Principal Spillway (Semi-Annually)
Type: Reinforced Concrete___
Corrugated Pipe_____
Masonry_____
Low-flow orifice obstructed
Low-flow trash rack
Debris removal necessary
Corrosion control
Weir trash rack maintenance
Debris removal necessary
Corrosion control
Excessive Sediment accumulation inside riser.
Concrete/Masonry condition riser and barrels
cracks or displacement
Minor spalling (<1”)
Major spalling (rebars exposed)
Joint failures
Water tightness
Metal pipe Condition.
Control Valve
Operational/
Exercised
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Infiltration Pond
Operation, Maintenance, and Management
Inspection Checklist
Project:Date:
Location:Time:
Site Status:Inspector:
Chained and Locked
Basin Drain Valve
Operational/ Exercised
Outfall channels functioning.
3.Dry Basin Areas (Semi-Annually)
Vegetation adequate. Area free of
accumulated organic matter.
Undesirable vegetative growth.
Undesirable woody vegetation.
Low-flow channels clear of obstructions.
Standing water or wet spots.
Annual mowing of vegetation along the
maintenance access roads.
Annual inspection of vegetation within basin.
Prune all dead or dying vegetation within the
extents of the basin or WVTS.
Sediment and/or trash accumulation
Remove all herbaceous vegetation root stock
when overcrowding of the maintenance
access to the facility, remove any vegetation
that has a negative impact on stormwater
flowage through facility, and trim any
overgrown vegetation within the basin.
Replace any/all original vegetation that has
died off or has not fully established, as
determined at the time of the inspection.
Any invasive vegetation encroaching upon
the perimeter of the facility should be pruned
or removed if it is prohibiting access to the
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Infiltration Pond
Operation, Maintenance, and Management
Inspection Checklist
Project:Date:
Location:Time:
Site Status:Inspector:
facility, compromising sight visibility and/or
compromising original design vegetation.
4.Condition of Outfalls (Semi-Annually)
Riprap failures.
Slope erosion.
Storm drain pipes.
Endwalls/ Headwalls
Other (specify).
5.Emergent Vegetation (Semi-Annually)
Semi-annual mowing of vegetation: Semi-
Annual mowing of the basin setback is only
required along maintenance rights-of-way
and the embankment. The remaining setback
can be managed as rangeland or forest.
Dominant emergent plants: Survival of
desired emergent plant species. Distribution
according to planting plan.
Evidence of invasive species.
Maintenance of adequate water depths for
desired emergent plant species.
Harvesting of emergent plantings needed.
Have sediment accumulations reduced pool
volume significantly or are plants “choked”
with sediment.
Eutrophication level of the WVTS.
6.Permanent Lined Concrete Chute Area (Semi-Annually)
Upstream face.
32
Infiltration Pond
Operation, Maintenance, and Management
Inspection Checklist
Project:Date:
Location:Time:
Site Status:Inspector:
Downstream face.
Seeps/leaks on concrete face.
Joint failures.
Riprap failures.
Concrete Chute not displacing .
Spillway clear of obstructions, debris,
sediment and/or trash accumulation.
7.Monitoring Well (Semi-Annually)
Opening clear of debris/ easily located.
8.Draw Down System (Semi-Annually)
Pipe outlet clear of debris/ easily located.
Sock clear of sediment/ blockage.
Perforated and solid pipe clear of sediment/
debris.
Valve location clear of debris/ easily located.
COMMENTS:
33
Infiltration Pond
Operation, Maintenance, and Management
Inspection Checklist
Project:Date:
Location:Time:
Site Status:Inspector:
ACTIONS TO BE TAKEN:
34
Stevens Street Multi-Family
Appendix B –Sample Stormwater Facility Maintenance Agreement
**A site-specific Stormwater Facility Maintenance Agreement between the Owner and the
responsible authority must be developed prior to construction**
35
Stevens Street Multi-Family
36
Stevens Street Multi-Family
37
Stevens Street Multi-Family
Appendix C – Stormcrete Operation and Maintenance Manual
38
Stormcrete® Modular Precast Porous Concrete Stormwater System
Operation and Maintenance Manual
Introduction:
Stormcrete® is a modular precast porous
concrete stormwater system which provides a
low-risk alternative to poured in place porous
pavements. Routine operation and maintenance
(O&M) procedures are similar to that of
conventional porous pavements. However,
Stormcrete® provides the security of knowing
that the slabs can be easily lifted for
maintenance and repairs or in some cases even
replaced when standard maintenance practices
are insufficient.
Planning / Placement:
Proper planning and placement of porous surfaces is fundamental to their longevity and
effectiveness. All projects are unique and careful attention should be taken to each situation.
Locate porous surfaces where they will be most effective from a stormwater management
perspective and least susceptible to heavy loading of sediment and debris. For example, potential
issues can arise in the following locations; site entrances, heavy commercial traffic, and landscaped
areas that may erode onto the porous surface.
Particular attention should be given to the amount of run-on flow from contributing impervious
areas (the Run-on Ratio). To avoid concentrating sediment in one location run-on flow should be
consistently introduced across a row of Stormcrete® Slabs and not directed towards a limited
number of slabs.
When choosing landscape plantings around a Stormcrete® System installations care should be
taken to minimize the potential for heavy organic material loading from surrounding vegetation.
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Regular Inspection:
Regular inspection of the Stormcrete® System is critical to developing a site-specific
maintenance program. Inspection should be performed several times in the first few months and
then 2-4 times per year depending upon the intensity of use. The following should be included in
any ongoing inspection program:
• During inspection note the accumulation of sediment and debris. Voids should be
checked for accumulation of fine material. This will aid in determining proper vacuum
sweeping frequency and the ability to target areas with higher accumulation rates.
• Inspect for evidence of run-on from perimeter unpaved areas or nearby erosion.
• Inspect for evidence of ponding. (i.e. staining or unusual light sediment or debris)
• Confirm “good housekeeping” practices are in place. Do not store materials such as;
mulch, soil, yard waste, and other stock piles on Stormcrete® slab surfaces or in such a
way that the material can be washed or blown on to the Stormcrete® slab surface.
• During inspection note the accumulation of sediment and debris. Voids should be
checked for accumulation of fine material. This will aid in determining proper vacuum
sweeping frequency and the ability to target areas with higher accumulation rates.
• Inspect for surface deficiencies. (i.e. raveling, spalling, cracking, etc.)
• Inspect for evidence of ponding. (i.e. staining or unusual light sediment or debris)
• Inspect for evidence of run-on from perimeter unpaved areas or nearby erosion.
• Inspect for evidence of accidental or illicit spillage.
• Maintain a log detailing all inspection and maintenance activities.
Maintenance During Construction:
Installed Stormcrete® System Panels should be properly protected post installation, but before the
System is accepted by owners in the following manner:
• Vehicular Traffic: Protect slabs from heavy construction equipment loads by using
smaller vehicles when possible or protective measures such as steel plates to spread the
load experienced by installed Panels.
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• Sediment and Debris: Use impervious liner material (heavy gauge HDPE sheeting) and
plywood as necessary to cover installed Stormcrete® System panels to protect them
from dirty tires and sediment and debris deposition. In some installations it may be
advisable to maintain a gravel-filled trench immediately adjacent to the Stormcrete®
System installation to intercept sediment and debris laden stormwater flows before they
run onto the system.
• Remove sediment and debris from Panels as needed: A backpack blower should be
kept on-site during the construction period to remove sediment and debris before it is
ground into the panel surface.
Routine Post Construction Maintenance:
Even with the advantages of the Stormcrete® System, all porous surfaces require some routine
maintenance activities to preserve permeability and service life. A minimum amount of planning
and regular maintenance is more effective than surface rehabilitation or replacement.
• Blower: A high-powered backpack blower (similar to a Stihl BR600) can be used with a
swirl pattern to loosen sediment and debris lodged into the Stormcrete® System. A
vacuum can be used to remove the material dislodged by the blower.
Vacuum Sweeping: Vacuuming a minimum of 2
times per year is recommended for most
installations. See WINTER
MAINTENANCE/SNOW REMOVAL below for
specific information on required winter
maintenance activities.
Site specific conditions (land use, climate, tree
cover, slopes, construction activities, etc.) along
with data from regular inspections will ultimately
determine how frequently the surface should be
vacuumed. At a minimum, vacuum cleaning
should occur in spring and fall (after leaf
drop). Additional cleaning should be
scheduled any time accumulated sediment /
debris is visible on surface and may be
necessary for installations that are prone to
heavy sediment and debris loading, such as
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roadway gutters and parking lots. Sidewalks and pedestrian plazas will most likely require less
frequent maintenance.
• Proper Equipment: Use of a powerful vacuum for routine maintenance is critical.
Regenerative air vacuum sweepers and high-efficiency vacuum only sweepers are
recommended. Equipment condition and proper maintenance is also critical to maximize
vacuum efficiencies.
• Specialized equipment such as the Stormwater SUV™ may be used for sidewalks, green
alleys, pedestrian plazas, etc. for maximum porous surface cleaning effectiveness.
• Operator experience and diligence is critical to maximize vacuum efficiencies.
Vehicle speed, equipment settings, timing for proper access, and type of material
being removed are only a few of the factors an operator needs to properly gage.
• Maintenance Staff / Public awareness: On-site personnel and contractors
should be made aware of the porous surface and proper O&M procedures. (i.e.
signage / pavement demarcation, snow removal, etc.)
Rehabilitation, Repairs, and Replacement:
• Focused Power Washing: Power-washing can be an effective tool for unclogging
plugged areas. Power-washing should be used in conjunction with a focused, high-
velocity vacuum head so that debris is removed and not just displaced. Power-washing
should occur at moderate pressure and at low angle (<45 degrees) to drive materials into
the vacuum head. Care should be taken with water pressure until effect of water pressure
on surface is realized.
• Remove, Restore & Reset: In the event that focused power-washing does not provide
adequate flow capacity, the slab(s) can be lifted, removed, and replaced.
42
▪ Please note: Removal and replacement should be completed using Stormcrete®
lifting swivels. Refer to the Stormcrete® Handling & Installation Manual for
additional information.
• Replacement: In the event that the slab(s) is plugged beyond rehabilitation the slab(s)
can easily be removed and replaced.
Winter Maintenance / Snow Removal:
• De-icing & Chemicals:
• If possible, avoid applying sand to Stormcrete® surfaces.
• A minimum amount of deicing chemicals should be required for use due to
the infiltrative capacity of the Stormcrete® System. After thorough snow
removal on a Stormcrete® System surface any residual snow melt will
infiltrate leaving the surface dry.
▪ Due to the low water to cement ratio in porous concrete, Stormcrete® is
more resistant to deicing chemicals.
▪ Sodium Chloride may be used as necessary.
▪ Calcium Chloride may be used in limited amounts in colder environments
▪ Because of its corrosive nature Magnesium Chloride should not be used
with Stormcrete® Precast Porous Panels
Permeable pavement owners should realize a savings on deicing salt costs
because there will be no thaw and refreeze issues to contend with.
• Plowing & Snow Removal:
• Snow can be removed using conventional plow blades equipped with shoes,
although wherever possible plows should be equipped with a plastic or rubber
cutting edge. Well maintained plow blades can prevent damage to porous
surface. Back dragging is not recommended. Where possible, plow passes
should be made at a 45-degree angle to the slab joints.
• Operator training: Snow removal operators should be aware of the presence
of the Stormcrete® System and its importance to the property and
environment.
• Snow within pores of porous pavement can make them appear more snow
covered than standard impervious pavements. Porous surface should not be
“over worked” or scraped.
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• Wintertime Stormcrete® Maintenance:
• When accumulated sand and salt is observed on Stormcrete® Panel surfaces,
vacuum cleaning is recommended to minimize the potential for clogging and
to remove excess chlorides that are detrimental to the longevity of the product.
One or more wintertime maintenance activities may be required, increasing
the overall number of maintenance events at a site to plus or minus four times
per year.
Porous Pavement Maintenance:
As Stormwater Professionals we understand that pervious concrete and asphalt surfaces are
increasingly being integrated into stormwater management systems (SMS). As site specific
needs vary greatly, so do the availability of different sweeping programs.
In cold weather climates, porous surfaces are particularly sensitive to sediment buildup. As an
integral part of the SMS, the longevity and effectiveness of this significant capital investment is
directly related to its care and maintenance. At Stormwater Compliance, LLC, an affiliate of
Porous Technologies, LLC, we manage porous pavement as well as the care of entire stormwater
systems on site. Included in our services are complete documentation of condition and
performance and the restoration of surfaces to their originally intended function as may be
needed.
Please contact Sweeping@StormWaterComp.com ,or 1-877-271-9055 for guidance or a
professional services proposal tailored to meet your site-specific O & M needs.
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