Brookfield Avenue Landfill Closure and Post-Closure Use Project NC SWANA 2014 Fall Conference Wrightsville Beach Martin Sanford, PE October 14, 2014 Outline • Project Summary • Closure Design Components • End Use Plan – Public Use – Ecological restoration • Lessons Learned Brookfield Ave Landfill Project Project Summary • 132-acre New York City MSW landfill on Staten Island – Operated from 1966 to 1980 – Classified as Class 2 Inactive Hazardous Waste Disposal Site in 1986 • Existing utility infrastructure on the property – 48” Interceptor sewer and pump station – Triple reinforced concrete stormwater culvert – Water and gas lines • Project Schedule – Construction started in 2010 – Project currently in the two year contractor maintenance phase Brookfield Ave Landfill Project Richmond Creek East Cell Salt Marsh Wetlands Pump Station West Cell Pre Construction Aerial Photo Brookfield Ave Landfill Project Wetlands Design Summary • Complexity of final cover, remediation, and wetlands construction – – – – – Extensive Grading and Shaping Standard Subtitle D Landfill Cap Geotechnical Slurry Barrier Wall Active Gas Collection System and Flare Station Leachate Collection System • Extensive Landscaping Improvement • Wetland Restoration • Maintain access to existing infrastructure Brookfield Ave Landfill Project 2010 Aerial after Tree Clearing Brookfield Ave Landfill Project Typical Landfill Cap 6”- 36” TOPSOIL LAYER 12” BARRIER PROTECTION LAYER GEOCOMPOSITE DRAINAGE NET 40 mil LLDPE GEOMEMBRANE GEOCOMPOSITE DRAINAGE NET (GAS COLLECTION LAYER) MIN 12” INTERMEDIATE COVER/ GRADING LAYER 132 Acres of Landfill Cap NORTH Landfill Cap Brookfield Avenue Landfill Landfill Cap East Cell Landfill Cap West Cell Legend Groundwater Barrier Wall Enclosed Gas Flare Leachate Collection Trench Typical slurry barrier wall construction Wetland Restoration – East Cell Over Cap Wetland Restoration – Wetlands constructed over cap Brookfield Ave Landfill Project End Use Plan – Public Use Park and Recreational Areas • Public Use – “Ecological Restoration” – Total site 272 Acres – 15 Acres ACTIVE Recreation – Three Future Multi-Purpose Sports Fields – 257 Acres of protection and restoration for PASSIVE recreation • Park and Recreation Elements – Access and Parking – Pedestrian Pathways and Trails – ADA Considerations Brookfield Ave Landfill Project Post Closure “End Use Plan” Brookfield Ave Landfill Project NYCDEP End Use Plan – Ecological Restoration • Ecological Restoration – – – – – Re-introduce Native Plant Materials Re-introduce Wetland Areas Restore Salt Marsh Provide Wildlife Habitat Minimize Irrigation, Fertilizing and Herbicides – Improve Water Quality and Reduce Future Soil Erosion Brookfield Ave Landfill Project 2014 Aerial during Maintenance Period Brookfield Ave Landfill Project Lessons Learned • • • • • • Drainage Flaps Planting Berms Swale Crossings Pipe Crossings Site Access – Construction and End Use Protection from Public Access and Deer Brookfield Ave Landfill Project Drainage Flaps Problem: • Landfill side slopes were flat • Drainage flaps were long, 100 to 150 feet in some cases. – Future settlement of the flap could cause drainage issues. Solution • Extended completely under the road to the embankment to discharge offsite. Brookfield Ave Landfill Project Planting Berms Design • 36” topsoil for trees and shrubs – Mounds built on top of the landfill cap. • Problem – Berms blocked stormwater sheet flow. – Caused ponding and erosion. • Solution – Erosion gullies filled with filter fabric and riprap. – Install small basins and piping. Brookfield Ave Landfill Project Swale Crossings Design • Pedestrian and bike paths tied into the perimeter maintenance road and concrete swale Problem • No mechanism for people or bike riders to cross the swale Solution • Purchase grates, chip out the concrete, and install grates in place Brookfield Ave Landfill Project Pipe Crossings Design • Drop inlets placed at low points to convey stormwater. • 15” CPP pipes drained were installed under road. Problem • Clearance for CPP pipe during active construction. Solution • Pipes changed to 12” Ductile Iron Pipe. Brookfield Ave Landfill Project Site Access During Construction and End-Use • Construction site entrance through residential areas. – Concern with daily trucks access through the neighborhood. • Public park access – One access for both vehicles and pedestrians. – Additional parking and pedestrian entrances added. • Local FDNY input – 30 foot wide access to the flare. – Secondary access for emergencies. Brookfield Ave Landfill Project Protection from Public Access and Deer • Leachate collection system with nine pumping chambers. – Control panel located near pedestrian and bike paths. – Panels were exposed to tampering by the public. – Panels placed inside lockable cabinets to prevent park users from turning the pumps on and off. • Protection of 17,000 trees and shrubs. – Deer was observed eating the new plantings, which had to be replaced. – 10,000 feet of deer fence added to protect the newly planted landscaping. Brookfield Ave Landfill Project Other Keys to Project Success • Hauling of 2.4 million tons of soil materials – – – – Common Fill – 927,000 Protective Cover – 798,000 Wetland Topsoil – 125,000 Topsoil – 554,000 • Stakeholder Engagement – Citizen Advisory Committee – State and local government • Remaining Project Schedule – Contractor Maintenance Phase – Park areas scheduled to open in 2017 Brookfield Ave Landfill Project Thank You! QUESTIONS?