PREPARED UNDER The 319 Nonpoint Source Pollution Grant Program FUNDED BY MA Department of Environmental Protection Boston, MA PREPARED BY Vanasse Hangen Brustlin, Inc. Watertown, MA Horsley Witten Group, Inc. Sandwich, MA The Center for Watershed Protection Ellicott City, MD Stacey DePasquale Engineering, Inc. Lawrence, MA
Month XX, 2011 Location here
Why Stormwater Maintenance? Extends stormwater BMP longevity Maintains stormwater BMP performance over time Helps protect againstdownstream water quality impacts and flooding Physically removes trapped stormwater pollutants and disposes of them in upland areas Ensures that stormwater BMPs are functional, safe and attractive
Why Stormwater Maintenance (Cont.) Maintains property values Keeps unwanted nuisance plants and animals at bay Promotesunderstanding ofbmp systems and their importance in protection ecosystems Offers green job opportunities for landscape contractors and others
Factors Governing Pollutant Removal Effectiveness Estimated pollutant removal based on prior monitoring Contributing drainage area to a BMP Annual precipitation fraction that is captured by a BMP Criteria employed for the design/implementation Construction inspection/enforcement capabilities of watershed managers Maintenance performed over the long term
Maintenance Issues Inadequate access to inspect and maintain all components of system Recharge chambers Catch basins Distribution box Water quality chambers
Maintenance Issues (Cont.) Existing access points need to be maintained Manhole covers installed at grade and not paved over
Stormwater Management System Operation and Maintenance The stormwater management system must have an operation and maintenance plan that shall hllat a minimum i include: Stormwater management system(s) owners; The party(ies) t(i responsible for operation and maintenance; The routine and non routine maintenance tasks and a schedule; A plan that t shows the location of all stormwater t BMPs and discharge points; A description and delineation of public safety features; An estimated budget; and The funding source.
O&M Plan Components There are two key components to adequately maintaining stormwater management infrastructure: Periodic and scheduled inspections, and Maintenance scheduling and performance Routine Non routine
Longevity and Maintenance Engineered designs in the right settings experience few initial maintenance problems If the Daily Grind is addressed, LID practices will perform at a high level for an extended period of time
Stormwater Practice Maintenance Burden Maintenance Burden is a function of the type of facility as well as the design and implementation Constructed SW Wetland Medium to Easy Infiltration* Medium to Difficult Filters Medium to Difficult Green Roofs Medium Open Channels Medium to Easy *Except Drywells Easy
Typical Maintenance Elements Sediment removal or containment Sediment disposal Erosion and gully repair Trash and debris cleanout Structural and mechanical systems Vegetation pruning and replacement System repair and replacement
Excessive sediment accumulation Check surrounding site stabilization Hand remove with a flat shovel Sediment Removal If surface becomes clogged C t lti t b Core aerate or cultivate bare areas annually
Sediment Removal
Constructed Stormwater Wetland Maintenance Clean out trash racks and access gates Remove sediment from forebay every 5 yrs or after 50% loss in capacity whichever occurs first If 50% vegetative coverage is not achieved after 2 nd growing season, reinforcement planting is required Remove sediment and organic build up from gravel WVTS ~2 yrs For discharges >200 ft from cold water fisheries, inspect gravel trench outlet after every storm in first 3 months of operation. After that once annually.
Constructed Stormwater Wetland Maintenance Guidance Replace dead/damaged vegetation; Vegetation management around perimeter of constructed stormwater t wetland; Repair minor gullying; Repair embankmentstructural integrity (borrowing animals, seepage, slope sloughing); Repair structural elements (spillways, orifice, weir, etc.); and Major erosion (inflow/exit channels).
Don t Let Vegetative Management Slide
Infiltration i Maintenance Never use basin or area as temporary ESC facility Protect area from compaction during construction Bring on line only after upstream drainage area is stabilized Provide observation well in all trenches/chambers. Basin: Routine sediment cleanout, mowing at least twice a year, revegetate bare areas, litter & debris removal, & rejuvenation (remove top 6, roto till till to a depth of 12 ) ). Basin bottom should be restored to design specs. Trench/chambers: Pretreatment and trench sediment cleanout. Drywell: Pretreatment cleanout. Gutter/downspout system cleaning if needed. Provide direct access for maintenance/rehab.
Infiltration i Maintenance Guidance Basins: design may include dewatering methods in event of failure; Vegetation management around perimeter; Repair minor gullying; Repair embankment structural integrity y( (borrowing animals, seepage, slope sloughing); Repair structural elements (spillways, etc.); and Major erosion (inflow/exit channels).
Infiltration i Inspection Guidelines Annually and after large storms; Amount of sediment in forebay; Look for signs of wetness, dead or dying vegetation on basin bottom; Standing water in observation wells > 72 hours after a storm; Structural components (overflow spillways, trash racks, access gates, valves, pipes, weirs); and Areas of erosion and/or sediment accumulation.
Failed Infiltration Basin
Reconstructive BMP Surgery Failed infiltration basin to wet swale Failed infiltration basin to wet extended detention pond
l f d Failure to Perform Routine Maintenance Can Lead to More Costly Repair/Reconstruction
Permeable Pavement Regular vacuuming
Permeable Pavement Maintenance Never use permeable paving area as temporary ESC facility; Minimize use of sand and salt in winter months; Do not repave or reseal with impermeable materials; and ESC Plan must specify at a minimum: How sediment will be prevented from entering the pavement area Construction sequence Drainage management Vegetative ti stabilization ti
Permeable Pavement Maintenance Guidance Keep adjacent landscape areas well maintained and stabilized (erosion gullying quickly corrected). Post signs identifying permeable pavement. Grass pavers need mowing/reseeding of bare spots. Mow upgradient, contributing pervious areas, and seed any bare spots. Ensure paving surface drains properly after storms. Inspect surface annually for deterioration or spalling. Attach rollers to the bottoms of snowplows to prevent them from catching on the edges of pavers. Avoid stockpiling snow on permeable pavement.
Salt Reduction and Porous Asphalt hl DMA 1-HR AFTER PLOWING, 11AM -4*C PA 1-HR AFTER PLOWING, 11 AM -4*C
Sand/Organic Filters Maintenance Clean out pretreatment chamber when approx. ½ full via vactor truck, clam shell or equivalent; If standing water is observed above filtration bed, the top 2 3 should be removed and replaced; and Repair structural components (concrete, valves, pipes, inlet frame/grate, underdrain system).
Bioretention/Tree i Filter Maintenance Remove sediment from pretreatment when depth exceeds ½ design depth, clean/repair when drawdown exceeds 36 hours; Remove sediment from filter bed when depth exceeds 1, rehabilitate bed if standing water is present 48 hours after a storm (roto till or aerate); Refurbish mulchevery other year (tillexisting materialsinto into soil) as needed; Vegetative maintenance Repair erosion gullies; and repair structural components.
Bioretention i Inspection Guidelines Annually and after major storm events; Amount of sediment in pretreatment facility; Look for signs of wetness, dead or dying vegetation on bottom; Vegetation condition (dead/dying, overcrowding?); g); Mulch condition; Structural components (inlets, overflow spillways, underdrain pipes, weirs); and Areas of erosion and/or sediment accumulation.
Bioretention Long Term Maintenance Issues Maintaining permeability of bio media ~5 7 years, rototill when sediment >1 ~15 20 years, replace media if complete failure (standing water >48 hours after storm) Damage to structures, settling (change in design elevations) Replacement of timber weirs, check dams Root bound vegetation
Green Roof Maintenance Inspect green roof for leaks on a quarterly basis. Leaves and litter should be removed Extensive Vegetation may need to be watered periodically during the first season and during droughts Vegetation may need to be lightly fertilized and weeded once a year Intensive Vegetation should be maintained as any other landscaped area,e.g., e.g., pruning, irrigation.
Open Channels Maintenance Clean out pretreatment when approx ½ full, where applicable; Mowing, vegetation management; Litter/debris removal; Stabilization of eroded slopes; Discing/aeration of swale bottom; and Structural repairs (trash racks, weirs, etc).
What you don t see is really impressive dry swale Source: Martin Covington, P.E.
Open Channels Inspection Guidelines Annually and after storms; Vegetation condition; Structural components (check dams/weirs, stabilization); and Areas of erosion and/or sediment accumulation.
Swales Long Term Maintenance Issues Maintaining permeability of filter media (de thatching/aeration of swale bottom) Damage to structures, settling (change in design elevations) Replacement of timber weirs, check dams Preserve original design capacity
Inspections Site inspection worksheet
Inspections When to inspect? Spring thru fall During the typical routine landscape maintenance After large storm events During other extreme weather events
Inspections Walnut Avenue Elementary School, Union County Problem: Gullying after rain event Solution: Add a berm and/or plants Hanson House/Hanson Park Conservancy, Union County Success: Withstood rain event Slide provided courtesy of Rutgers New Jersey Agricultural Experiment Station
Snow Removal Snow removal is NOT required Avoid piling snow in bio areas Piled snow should not block inlets Photo courtesy of Rutgers New Jersey Agricultural Experiment Station
The Life Cycle Approach hto Stormwater t Mit Maintenance The most successful programs recognize that effective stormwater BMP maintenance involves more than just maintenance Plan Review
Maintenance Program Scoping What do the NPDES Phase II stormwater program rules require an MS4 to do? Ensure adequate long term operation and maintenance of post construction stormwater controls Not exactly a lot of guidance here
Maintenance Program Scoping Questions What are the local watershed protection and restoration objectives? How many stormwater BMPs are currently in place? How many more stormwater BMPs are expected? Where will they be located? Who will maintain them? What will be the level of service provided by the community? How can the program be funded?
Program Level of Service Complaint driven /political program Regular inspection and maintenance schedule Inspection reports and record keeping Public vs. private maintenance Program funding
Maintenance Program Models Communities have several different options to consider when vesting maintenance responsibilities Option 1: Private Maintenance Option 2: Public Maintenance Option 3: Hybrid
Maintenance Program Options Option 1: Private Maintenance Community responsible for public stormwater controls, homeowners or businesses have responsibility for private controls Reduces costs Good option for small communities with limited staff Community still responsible for education, tracking and enforcement
Key Considerations i for Option 1 Who should conduct routine inspections? How to ensure that maintenance continues when properties change hands? When should enforcement be used?
Maintenance Program Options Option 2: Public Maintenance Community has full responsibility for maintenance of both public and private stormwater controls Uncommon due to costs Better control Requires dedicated staff and funding Avoids legal lroadblocks and questions
Key Considerations i for Option 2 Should the community assume responsibility for all stormwater BMPs? What types of funding are available? Who should conduct routine maintenance such as mowing and trash pick up? Who should conduct routine inspections? How will stormwater BMP maintenance be tracked? Are all BMPs readily accessible?
Maintenance Program Options Option 3: Hybrid Community has responsibility for public stormwater controls and for private stormwater controls that handle public (off site) stormwater runoff Combination of Options 1 and 2 Better control Requires ddi dedicated dstaff and funding More expensive than Option 1
Budgeting for a Local Maintenance Program Staff Equipment Administration Tracking/GIS Contractual Services Other
Stormwater Program Elements For NPDES Phase II communities, at a minimum, according to US EPA: MM1: Public Education and Outreach MM2: Public Involvement and Participation i MM3: Illicit Discharge Detection and Elimination MM4: Construction Site Runoff Control MM5: Post Construction Runoff Management MM6: Municipal Pollution Prevention/Good Housekeeping They really require these too: XX: Maintenance YY: ProgramEvaluation and Reporting
CWP. 2008. Managing Stormwater in Your Community: A Guide to Building an Effective Post-Construction Program
Tips for Building a Better Maintenance Program Most local programs are established on shoestring budgets, but some small early investments can yield major reductions in long term maintenance costs for the community as a whole The overall theme is to use the life cycle approach The overall theme is to use the life cycle approach to building your maintenance program
Tip 1: Include Maintenance Requirements in Local Ordinance Identifyspecific entity responsible for long term, routine maintenance Reference design guidelines to minimize i i maintenance burden Specify regular inspection visits Require inspection access and/or easements Include special provisions to handle emergency maintenance Outline escalating levels of enforcement
Tip 2: Reduce Maintenance Liability During BMP Selection & Design Reduce maintenanceheadaches with tough design standards if you don t ask for it, you won t get it! Include low maintenance, nonstructural BMPs Thorough plan review ensures design standards are properly implemented Review the plan asif you were the maintenance crews or have maintenance staff actually review the plans Get standards off the books and onto site plans!
Review site plans with maintenance in mind Require detailed maintenance plan Inspection schedule Maintenance frequency Responsible party Require pretreatment Strive to make sediment removal operations quick and easy Design practices with gentle side slopes Include nativevegetative vegetative no mow buffers around stormwater practices Require long term vegetation management plan Require an estimation of cost for maintenance Plan Review Checklist Pretreatment Maintenance Access Landscaping Plan
Tip 3: Require Maintenance Easements Parcels dedicated to stormwater management Access easements Drainage (conveyance) easements Decisions: i Dedicated to public? Deed restrictions?
Tip 4: Use Maintenance Agreements and Bonds Detailed maintenance agreement and plan based on type of stormwater BMP Maintenance agreements tied to property deed d Construction bonds Maintenance bonds?
Tip 5: Conduct tinspections During AND After Construction Use inspections to check progress and quality of installation, not just for erosion and sediment control Annual maintenance inspections Use detailed inspection checklists 1 FTE: 250 to 500 BMPs/year Third party inspections?
Tip 6: Routine and Thorough Inspections After Construction Annual inspections Detailed inspection checklists Measurements where available Mark problem areas (e.g. spray paint) Issue work orders to correct problems Third party inspections?
Inspection Checklists Be quantitative, so that maintenance can be prioritized (e.g., "0 4" system) Be very specific about possible problems to reduce subjectivity and clearly identify corrective actions Limit the use of text, particularly when using a database Track the function of practices over time for future regulation revisions (e.g., pretreatment, wetland vegetation)
Tip 7: Progressive Enforcement and Corrective Action Focus on education first Notify property owners of maintenance requirements Develop different stages of enforcement Decide when and how to pursue corrective actions Methods of paying for remedial actions
Tip 8: Synchronize Field Data and Office Data
Tip 9: Track and Document Activities iii Inventory existing stormwater BMPs Track inspection and maintenance reports Schedule inspections and remedial actions Provide documentation for legal action Relate design features to BMP performance Identify stormwater retrofit opportunities
database (full size)
Tip 12: Educate and Involve the Maintainers i BMP owner s manuals and other educational materials Adopt a Pond programs Volunteer cleanup events
Tip 13: Practice Co Inspections Owner inspections are a key part of a successful maintenance program: Notification of inspection requirements Invitations to accompany maintenance inspections Inspection training workshops Provide inspection schedules and checklists
Questions?
CONTACT INFORMATION Bethany E. Eisenberg Director of Stormwater Services VHB VanasseHangen Brustlin, Inc. 101 Walnut Street Watertown, MA 02472 Phone: 617.924.1770 x1229 Fax: 617.924.2286 Direct: 617.607.1852 beisenberg@vhb.com www.vhb.com Richard A. Claytor, Jr., P.E. Principal Engineer Horsley Witten Group 90 Route 6A, Sandwich, MA 02563 508 833 6600 rclaytor@horsleywitten.com www.horsleywitten.com Deb Caraco Center for Watershed Protection Field Office: 606 N. Aurora St., Ithaca, NY 14850 Main Office: 8390 Main Street, 2nd Floor, Ellicott City, MD 21043 607.277.6337 410.461.8323 dsc@cwp.org www.cwp.org Stacey A. DePasquale, P.E. President SDE 354 Merrimack kstreet, Suite 200 Lawrence, MA 01843 1755 978 975 0500 sdepasquale@sde inc.com http://www.sde inc.com/ www.vhb.com/stormwaterseminars