The Operational Components of Waste Management

2.
The Operational Components of Waste Management

The waste management operations consist of waste collection, area cleaning and waste disposal. Waste collection and Area Cleaning constitute the core functions of waste management. Resources between the two operations are often shared or integrated. A Collection beat is defined as an activity that is covered by a specific collection vehicle per day. The CoCT is currently divided into 601 department refuse collection beats serving 473 400 erven and a population of approximately 2.5 million people. Approximately 560 000 tons are collected annually from 744 000 formal (81%) households and informal (19%) service points.

There are three levels of collection service, ie a containerised service (240l “wheelie” bins), plastic refuse bags (85l) and skips for rudimentary services. The CoCT contracts out the skip collection services and certain other collection services. The CoCT’s collection vehicles account for approximately 33% of the total waste disposed of to landfill.

Area Cleaning comprises street sweeping, litter picking, beach cleaning, clearing of illegal dumping, animal carcass collection, provision and servicing of litter bins, clearing hawker waste and provide water tanker services for control of wind-blown litter. The CoCT undertakes most of the area cleaning activities, although a number of other departments outside of Solid Waste also engage in area cleaning. More than 95% of the CoCT’s inhabitants receive an effective service in terms of waste collection and area cleaning.

Once waste has been collected or areas have been cleared it needs to be disposed of. Waste disposal entails the landfilling of waste, provides refuse transfer stations and drop-off facilities and compost waste at two facilities. Modern landfills aim to contain waste safely and hygienically in specially engineered cells in the ground. Legislation governing the siting, design, engineering and operation of sanitary landfills aim to combat potential environmental problems. A landfill should be a reasonable distance away from any human habitation, but close enough to where domestic waste is generated to limit transportation costs. The underlying soil structures, soil type and drainage patterns of a potential site must also be taken into account in order to minimise the impact of the landfill on the surrounding environment. The landfill is usually lined with clay or high density polyethylene (HDPE) to protect the underlying groundwater from leachate infiltration. Waste deposited in the lined cells are compacted and covered daily to prevent the waste from blowing around and discourage animals and vermin, reduce odours and saves landfill airspace. The decomposition of waste is by both aerobic and anaerobic bacteria and can continue for many years from date of deposition. Once a landfill is closed, it is rehabilitated, capped and may be used as public open space, sports fields or agriculture. Under no circumstances may it be used for housing, due to the risk posed by settlement of the waste and the generation of methane gas, which is explosive.

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Sumber:
Core Notes for Module 6 (Elective) of the Course
“Environmental Engineering – Sustainable Development in Coastal Areas”
Cape Peninsula University of Technology (CPUT)
Cape Town, South Africa
2006
Available to Distance Learners on www.dlist-benguela.org