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Analysis of Technology Choices


Use Cost-Effective Collection Methods

Solid waste collection systems consume a significant portion of city revenues. Collection is labor, fuel, and vehicle intensive, and needs to be repeated daily. Commonly, in poorer countries where people do not cooperate with waste collection systems, and where traffic and road access slows the productivity of the workers and vehicles, costs tend to be high proportionate to income compared to collection costs in richer countries. To determine cost-effective collection methods requires careful analysis (pdf) of alternatives, using local unit costs for labor, equipment, consumables (such as fuel), civil works, and land, combined with typical local productivity norms. In evaluating collection options, it is typical to conduct time-and-motion studies of existing systems and test various crew sizes and operating methods. Systems that involve the voluntary effort of residents to walk to communal containers often offer the lowest possible costs, as the city pays only for hauling or emptying the container. Door-to-door systems, even if by pushcart, are more costly, but may be preferred and might lead to greater willingness to pay cost recovery charges.

Select Appropriate Collection Vehicles 

Direct haul in collection (pdf) vehicles (i.e., from the collection route to the point of ultimate disposal) is typically compared with haul to transfer (pdf) stations from which large volume transfer vehicles take the waste to the ultimate disposal site. For each size and type of collection truck, there is a unique direct haul distance that is economical. The smaller and slower the collection vehicle, the shorter the viable direct haul distance. Large-bodied compaction trucks may be chosen to service down-town city centers where traffic is slow and distance to disposal is long; while smaller versatile farm tractors and trailers may be chosen to service peripheral semi-urban areas and the distance to disposal is short.

Account for All Land Disposal Uses

Land disposal is an essential part of every city solid waste management system. Regardless of the extent of recycling or resource recovery, there are always some wastes that must be put in a land disposal site (e.g., ashes from incineration (pdf), non-compostable residuals). Most developing countries employ open dumping as their form of land disposal. In virtually all developing countries there is an urgent need to close existing open dumpsites and implement sanitary landfills (pdf). Because of sanitary landfill’s costs, cities tend to make little progress toward landfill implementation unless the regulatory framework and environmental agency apply enforcement pressure. Bank support for landfill has provided significant support to cities wishing to make this transition from open dumping.

Maximize on Opportunities in Resource Recovery Technologies

To the extent that markets for recovered resources could cover cost differences beyond sanitary landfill, resource recovery technologies (see video on Landfill Gas Recovery (.rm video), and paper on Composting and Its Applicability in Developing Countries) should be implemented to reduce the landfill requirement. Unfortunately, there are limited markets willing to pay adequately for compost, landfill gas, or electricity from waste incineration. Carbon financing (see presentations on Municipal Solid Waste and Carbon Finance (pdf), and Carbon Finance and Infrastructure: Africa Region Experience (pdf)), emission trading (see presentations on The Solid Waste Context for Carbon Finance in Developing Countries (pdf) and Waste Collection Planning Tool: Cost Analysis of Collection Options (pdf); and paper on Environment Network: Economic Instruments for Solid Waste Management: Global Review and Applications for Latin America and the Caribbean (pdf)), and environmental funds may sweeten the deal to help justify these more costly disposal options. The World Bank conducts several funds that provide economic incentives to upgrade disposal, including the Prototype Carbon Fund and the Global Environmental Facility.

Include All Stakeholders in Land Siting & Design Process

Land siting for a transfer station, landfill, incinerator, and/or composting plant is generally a contentious issue, most commonly opposed by people (pdf) living in the immediate area of the proposed site and along the route that the waste transport trucks are expected to use. Providing commitments to employing monitoring and community liaison staff from the community, and also giving priority to local residents for new jobs created by the site, can help to win site approval. Most cities also offer free unloading of wastes to the host community and/or a share of revenues obtained from tipping fees paid by users. Site designs that provide vegetative buffer zones, curved internal access roads that limit sight-lines into the facility, and environmental mitigation measures that minimize emissions may further be included to secure public consensus.


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