09.0 Waste Collection.ppt 4531KB Mar 29 2010 05:00:27 AM

9 – Waste Collection

Content:
• Separation at source
• Waste collection, transfer and transport
• Organization of waste collection

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9 – Waste Collection

9.1 Separation at source

Most urban places in the developing world have yet to experience the
decline of traditional recovery of recyclables and the corresponding
increase in post-consumer wastes, which, together with scarcity of dump
space, have led many affluent cities to sponsor materials recovery.

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9 – Waste Collection

9.2 Waste collection, transfer and transport

Collection is by far the largest cost element in most MSWM systems
• Accounting for 60-70% of costs in industrialized countries,
• And 70-90% of costs in developing and transition countries.
• Collection (and street sweeping together) comprise the single largest
category of expenditure in municipal budgets.
Failure or inadequacy of collection, especially in developing countries where
there is frequently considerable human fecal waste in the municipal solid
waste, can lead to threats to public health.

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9 – Waste Collection

9.2 Waste collection, transfer and transport

Various collection and container systems are used
• door-to-door collection
• indirect collection, with containers/communal bins placed near markets, in
apartment complexes, and in other appropriate locations and hauled to
transfer stations and disposal sites by vehicles.

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9 – Waste Collection

9.2 Waste collection, transfer and transport

Collection vehicles
Based on a collector or collection crew which moves through the collection
service area with a vehicle for collecting the waste or materials.
The vehicle may be small and simple as small as a two-wheeled cart pulled
by an individual or large, complex, and energy intensive, such as the rearloading compactor trucks used in many industrialized cities.

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9 – Waste Collection

9.2 Waste collection, transfer and transport

Muscle-powered or micro-mechanical vehicles work well:
• in densely populated areas
• in squatter settlements;
• on hilly, wet or rough terrain; and
• with small volumes of waste and densely settled housing units.
The disadvantages of muscle-powered vehicles are:
• perception of use animals / human power as old-fashioned / shameful;
• vehicles have limited traveling range and are slow;
• animals pulling vehicles leave waste, which must be cleaned up;
• effect of weather exposure on humans not in motorized vehicles;
• problems of animal temperament, health, etc.
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9 – Waste Collection

9.2 Waste collection, transfer and transport

Non-compactor trucks
Sound technical practice for solid waste collection when:
•the waste is very wet or dense;
•labor is relatively inexpensive, compared to capital;
•limited need of highly skilled maintenance;
•collection routes are long and relatively sparsely populated;
•controlling capital and operating costs is very important; and
•downtime for maintenance must be minimized.
Disadvantages:
•political: government see compactors as means to modernize waste
collection system (non-compactor trucks having low status);
•salesmen recommend compactor trucks;
•donor agencies from industrialized countries recommend equipment
associated with efficient collection in their own countries (compactor trucks)

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9 – Waste Collection

9.2 Waste collection, transfer and transport

Compactor trucks (standard of sound practice for
waste collection in Industrialized countries and cities):
•waste containers are emptied in the vehicle
•compacts the waste to high density
•removes the waste from view quickly;
•inhibits vectors + insects from reaching waste
•Characteristics:
•high capital cost;
•sensitive hydraulic mechanisms (must be well maintained and can
break when compacting waste that is already dense).
•high fuel usage and operating cost;
•moderate skill level to operate;
•at least two persons needed to operate under most conditions.)

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9 – Waste Collection

9.2 Waste collection, transfer and transport

Containers
Most collection systems depend set-out containers.
Aspects for consideration:
- materials, size, and volume
- Baskets / paper bags to promote decomposition and
prevent odors
- Theft of containers?
- Color?
- Separate container for recycable materials?
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9.3 Organization of waste collection

Administrative structures for MSW collection and transfer services
•The frequency of collection ranges from once or twice a week to daily
collection.
•Collection crews are directly employed with fixed working hours, holidays,
and other benefits
•Decentralized Pre-collection - Indonesia now has a good system of MSW
collection
•useful for raising collection rates.
•the kampungs ("villages") of Indonesian cities have responsibility for
primary collection,
•the wastes of the area being deposited at a transfer or temporary
storage point for collection by the city service.

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9 – Waste Collection

9.3 Organization of waste collection

Collection Points
may be a:
• container,
•a concrete vat,
•a road side,
•or an open area.
The type of vehicles used varies from city to city, and within one urban area,
according to the type of container system and the funds available for
purchasing or hiring vehicles.
For example, in large cities, open flatbed trucks, covered trucks, and some
compactors are in use, whereas in smaller cities tractor-trailers and animal
carts are common.
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9 – Waste Collection

9.3 Organization of waste collection

Route design and operation
•Collection of waste or recyclables organized in service areas.
•A service area is the region or area which falls under the responsibility
of a government, public authority, or private company.
•Within the service area, collection is organized into routes. A route is the
path followed by a single collection vehicle for waste collection on a single
day.
•Collection efficiency
•Critical as it is the main determinant of collection cost
•An efficient collection system aims to collect as much waste as possible
with a given amount of labor, capital, and time.

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