SOLID WASTE TRANSFER SOLID WASTE TRANSFER SYSTEMSSYSTEMS

IN DEVELOPING IN DEVELOPING COUNTRIESCOUNTRIES

Sandra CointreauSandra Cointreau

WHAT IS A TRANSFER SYSTEM?WHAT IS A TRANSFER SYSTEM?

• A Transfer System Consists of a Transfer A Transfer System Consists of a Transfer Station and a Fleet of Large Capacity Station and a Fleet of Large Capacity Vehicles Which Provide Long Haul for Vehicles Which Provide Long Haul for Refuse -- So That the Fleet of Small Refuse -- So That the Fleet of Small Capacity Collection Vehicles Is Enabled to Capacity Collection Vehicles Is Enabled to Focus on the Job of Collection. Focus on the Job of Collection.

Transfer Transfer Systems Systems Enable Enable Reducing Reducing Collection Collection Haul Haul Distance, Distance, Vehicle Vehicle Emissions Emissions and Costs By and Costs By 20 To 50 20 To 50 PercentPercent

Solid Waste Collection and Transfer Vehicle Costs in Trinidad and Tobago, 1999

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$5.00

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REAR LOADER MANUAL 10.0 TRANSFER TRUCK TRAILERS 60.0

Determine Transfer Determine Transfer Breakpoints:Breakpoints:

• Each type and size Each type and size of collection of collection vehicle has a vehicle has a different transfer different transfer breakpointbreakpoint

• Traffic speed Traffic speed affects the transfer affects the transfer breakpointbreakpoint

• Consider transfer Consider transfer for hauls over 30 for hauls over 30 minutesminutes

COST ($US/Tonne) FOR COLLECTION AND TRANSFER SYSTEMS - GOVERNMENT SERVICE -

Georgetown, Guyana- 1999

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REAR LOADERMANUAL 10

TRANSFERSYSTEM W/COLL.TRUCKS

TRANSFERTRUCK W/FACILITY

TRANSFERTRUCK 60

TRANSFERSTATION

Transfer Systems Enable Transfer Systems Enable Implementation Of Regional Implementation Of Regional Safe Disposal Systems that Safe Disposal Systems that

Achieve Economies-of-Scale.Achieve Economies-of-Scale.• Landfills should be at least 300 tonnes/day to Landfills should be at least 300 tonnes/day to

have landfill bulldozers and wheeled loaders have landfill bulldozers and wheeled loaders fully utilizedfully utilized

• Roads, fences, weighbridges, gatehouses, Roads, fences, weighbridges, gatehouses, utilities are fixed costs that should be applied to utilities are fixed costs that should be applied to large waste quantitieslarge waste quantities

Landfill Economies-of-Landfill Economies-of-ScaleScale

Landfill Costs - Trinidad and Tobago, 1999

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Investment Cost/Tonne - Clay and Geomembrane Total Cost/Tonne - Clay and Geomembrane

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Transfer Stations have Carbon Transfer Stations have Carbon Finance OpportunitiesFinance Opportunities• All transfer vehicles are parked and fueled at All transfer vehicles are parked and fueled at

the station and able to operate with clean the station and able to operate with clean fuels and upgraded emission controls.fuels and upgraded emission controls.

• Collection haul distances are dramatically Collection haul distances are dramatically reduced, and thus their emissions are reduced, and thus their emissions are reduced.reduced.

• Reductions are easy to monitor because of Reductions are easy to monitor because of weighbridges required at transfer stations.weighbridges required at transfer stations.

What Are The Main Elements Of What Are The Main Elements Of A Major Transfer Station?A Major Transfer Station?

• Site of 2+ Hectares Site of 2+ Hectares

• Access to a Major Road Which Can Carry Long Access to a Major Road Which Can Carry Long Haul Vehicles of 50 C.M. CapacityHaul Vehicles of 50 C.M. Capacity

• Parking, Maintenance and Repair Facilities for Parking, Maintenance and Repair Facilities for Transfer FleetTransfer Fleet

• Weigh-Bridge to Record in-Coming PayloadsWeigh-Bridge to Record in-Coming Payloads

• Multi-Level Transfer Building, Unloading on Top, Multi-Level Transfer Building, Unloading on Top, Loading on BottomLoading on Bottom

Typical 2-Level Transfer Typical 2-Level Transfer StationsStations

Manila, Philippines, 1993Manila, Philippines, 1993

Quito, Ecuador, 1998Quito, Ecuador, 1998

Which Design Issues Need Which Design Issues Need Careful Analysis?Careful Analysis?

• Station Layout for Efficient Traffic Flow Station Layout for Efficient Traffic Flow of Collection and Transfer Vehiclesof Collection and Transfer Vehicles

• Unloading Method from Collection Unloading Method from Collection Vehicles Vehicles

• Loading Method of Transfer VehiclesLoading Method of Transfer Vehicles

• Transfer Vehicle Style and MaterialTransfer Vehicle Style and Material

• Discharge Method from Transfer Discharge Method from Transfer VehiclesVehicles

Direct Unloading Direct Unloading to Transfer Truck to Transfer Truck

• Waste Is Discharged Directly from the Waste Is Discharged Directly from the Collection Vehicles into the Loading Collection Vehicles into the Loading System of the Transfer Vehicles System of the Transfer Vehicles

• No Waste Storage, Therefore Less Need No Waste Storage, Therefore Less Need for Odor and Vector Controlfor Odor and Vector Control

• Usually Used for Small Stations OnlyUsually Used for Small Stations Only

Direct Unloading Direct Unloading to Transfer Truckto Transfer Truck

Hyderabad, India, Skip Container Hyderabad, India, Skip Container Lift Collection Truck, Unloads to Lift Collection Truck, Unloads to Open Tipping Truck, 2001Open Tipping Truck, 2001

Unloading-to-Storage Area Unloading-to-Storage Area • Waste Is Discharged to a Storage Area Waste Is Discharged to a Storage Area

from which It Is Then Moved into the from which It Is Then Moved into the Loading System of the Transfer VehiclesLoading System of the Transfer Vehicles

• Storage Enables Collection Vehicles to Storage Enables Collection Vehicles to Operate on Their Optimum Schedule Operate on Their Optimum Schedule and Transfer Vehicles to Operate on and Transfer Vehicles to Operate on Their Optimum ScheduleTheir Optimum Schedule

• Provides a Safe-Guard if Their Is Down-Provides a Safe-Guard if Their Is Down-Time in the Loading System for Transfer Time in the Loading System for Transfer VehiclesVehicles

Unloading to Storage FloorUnloading to Storage Floor

Style Options:Style Options:

• Light-Weight Open Top TrailersLight-Weight Open Top Trailers– for direct open top loadingfor direct open top loading

• Light-Weight Closed Top TrailersLight-Weight Closed Top Trailers– for pre-load compactor loadingfor pre-load compactor loading

• Compactor-Compatible Closed Compactor-Compatible Closed Top TrailersTop Trailers– for stationary compactor loadingfor stationary compactor loading

• Self-Contained Compactor Self-Contained Compactor TrailersTrailers– for self-contained compactor loadingfor self-contained compactor loading

Types of Transfer VehiclesTypes of Transfer Vehicles

US, lightweight open topped, filled US, lightweight open topped, filled by gravity from hopperby gravity from hopper

US, lightweight, filled by US, lightweight, filled by extrusion from a compaction extrusion from a compaction chamberchamber

Types of Transfer VehiclesTypes of Transfer Vehicles

Singapore, Body filled by Stationary Singapore, Body filled by Stationary Compactor, 1993Compactor, 1993

Mexico, on-board Compactor, 1985Mexico, on-board Compactor, 1985

Material Options:Material Options:

• AluminumAluminum - - – lighter (by 15 to 20%) but more costly lighter (by 15 to 20%) but more costly

(by 40 to 60%)(by 40 to 60%)

• Steel Steel – more flexible, less likely to crack or more flexible, less likely to crack or

tear, easier to repairtear, easier to repair

Discharge Options:Discharge Options:

• Push-Blade Mounted at Front of Push-Blade Mounted at Front of Trailer Trailer – Takes up 10 to 15% of Trailer CapacityTakes up 10 to 15% of Trailer Capacity

• Live-Floor Mounted on Floor of Live-Floor Mounted on Floor of Trailer Trailer – Takes up 2 to 3% of Trailer Capacity, Takes up 2 to 3% of Trailer Capacity,

More Moving Parts Require More More Moving Parts Require More MaintenanceMaintenance

Discharge SystemsDischarge Systems

US, Walking Floors are Most CommonUS, Walking Floors are Most Common

Izmir, Turkey, On-board Ram Izmir, Turkey, On-board Ram Compactor also unloads, 1994Compactor also unloads, 1994

Discharge SystemsDischarge SystemsLandfill tipping machine allows Landfill tipping machine allows transfer trucks to be avoid the weight transfer trucks to be avoid the weight of an onboard unloading mechanismof an onboard unloading mechanism

US, large landfills with long US, large landfills with long transfer haul distances, able transfer haul distances, able to lift 10 trucks per hourto lift 10 trucks per hour

Choices Affect CostsChoices Affect Costs

• Choice of Loading System Can Affect Choice of Loading System Can Affect – Investment Cost by 35%Investment Cost by 35%– Total O,O&M Cost by 25%Total O,O&M Cost by 25%

• Choice of Vehicle Material Can AffectChoice of Vehicle Material Can Affect– Investment Cost by 50%Investment Cost by 50%– Total O,O&M Cost by 20%Total O,O&M Cost by 20%

• Choice of Discharge System Can AffectChoice of Discharge System Can Affect– Investment Cost by 20%Investment Cost by 20%– Total O,O&M Cost by 50%Total O,O&M Cost by 50%

Transfer Stations are the Heart of Transfer Stations are the Heart of Economic Solid Waste Systems:Economic Solid Waste Systems:

• Enable performance monitoring of collection by Enable performance monitoring of collection by weighbridge and computerized MIS.weighbridge and computerized MIS.

• Allow collection systems to be rationalized.Allow collection systems to be rationalized.• Allow fuel to be conserved.Allow fuel to be conserved.• Allow bundling of waste into inter-municipal Allow bundling of waste into inter-municipal

regions for economic sanitary landfill. regions for economic sanitary landfill.

Paper and film of presentation Paper and film of presentation available at:available at:

• http://www.worldbank.org/urban/uswmhttp://www.worldbank.org/urban/uswm

Thank you for your kind attention Thank you for your kind attention