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| A new subdivision on the urban periphery. Note the water service to the left, consisting of a well and pump, which provide water for about 100 residences. |
By George Wheeler, City of Toronto
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| A new subdivision on the urban periphery. Note the water service to the left, consisting of a well and pump, which provide water for about 100 residences. |
In December 1998 I spent a week in the City of Cochabamba, Bolivia, working with EMSA, a municipal solid waste utility.
My most important finding is that in Cochabamba, the provision of safe, non-infectious municipal drinking water would reduce the volume of municipal solid waste and improve both health and diet for the average wage earner. It would be better to allocate scarce municipal funds to provide safe municipal drinking water than to divert non-toxic and inert container materials (mostly plastic and glass).
The City of Cochabamba is approximately 100 square kilometres and has a population of approximately 600,000. Tap water must be boiled before drinking. The lack of clean safe drinking water impacts waste management, as bottled beverages, usually in plastic containers marked "descartable" (disposable), are a convenient if expensive alternative to boiling municipal tap water. This high volume waste affects both the collection and disposal management cost of Cochabamba's Municipal Solid Waste (MSW) system.
MSW Composition Cochabamba and Toronto
There are significant differences between the MSW waste stream in Cochabamba and Toronto which reflect differences in culture and economic development. Table 1 shows the percentage of each potentially recyclable and reusable waste in relation to total potentially recyclable and reusable waste and illustrates one of the most significant differences between the two cities. In Cochabamba, plastic and glass (mostly beverage containers) taken together are approximately 63% of potentially recyclable and reusable waste; the percentage in Toronto is 28.4%. Plastic alone in Cochabamba represents approximately 45% of reusable and recyclable waste, whereas in Toronto the percentage is only 17%.
Activity Based Costing (ABC)
Staff of the City of Toronto have used a form of "Activity Based Costing" (ABC) to evaluate the impact of material volumes and densities of the different components of MSW on total system costs. Removing a particular material will not reduce system operating costs by the amount of the estimated ABC cost impact of the material because of fixed costs. Rather ABC, when applied in the manner shown in Table 2, indicates that lower density materials, if increased or decreased in quantity, are most likely to have the greatest impact on total system cost. If high volume container wastes are removed, system redesign can produce system cost reductions. For example, beverage container wastes in the City of Toronto have been shown to occupy approximately half the volume of all "blue box" container wastes. If removed through deposit return, collection frequency, costs and environmental impacts of curbside recycling programs can be reduced.
Table 2 shows the impact of relative container density on garbage collection costs in Cochabamba, as indicated by ABC. It also indicates that, of the potentially recyclable materials, from an ABC standpoint, only paper and glass are close to the average collection cost per tonne for the collection of all wastes together. Plastic costs more than thirteen times as much to collect per tonne as the fully commingled waste stream. Plastic, and disposable plastic containers, as a large and growing percentage of Cochabamba's waste, will continue to have a major impact on the cost of EMSA's operations. High volume, inert plastic containers also have a major impact on reducing available landfill capacity.
Table 2 shows that in Bolivia, recyclable materials are valuable in relation to collection costs and incomes. For this reason, the curbside separation of these materials is impractical because the most valuable materials would be scavenged prior to collection. Like many South American cities, diversion of recyclable materials occurs at the landfill by scavengers who, in Cochabamba, reside on the landfill. EMSA has the cost of collecting low density containers without the benefit of the revenue from this waste.
Plastic represents a large and growing proportion of potentially reusable and recyclable waste because, without boiling, Cochabamba's municipal water cannot be safely consumed. Soft drinks and bottled water are ubiquitous in Cochabamba because of their convenience compared to boiling water. Vendors sell these beverages from sidewalk stalls everywhere. Homeowners in many neighbourhoods operate small businesses selling bottled water, soft drinks and other merchandise.
Other Benefits of Safe Water
Ironically, of two of the contributions which the West has to offer the developing world, safe and inexpensive municipal drinking water and a private market distribution network for the soft drink industry, only the latter comparatively more expensive system has been firmly established in Cochabamba.
Providing a safe municipal drinking water system in Cochabamba would have several environmental, public health and economic benefits. For the waste management system, high volume beverage container waste, which is expensive to collect, process and landfill, would be reduced. Waste management, including litter and street cleaning costs, also would be reduced. Gastrointestinal illness would be substantially reduced resulting in significantly improved public health. The use of bottled beverages as a method of distributing potable drinking fluids is not sustainable and, if the private distribution system collapses or if incomes fall precipitously, as they have from time to time in Latin America, the alternative of a safe municipal drinking water system may be unavailable.
However, Canadians and countries at a similar level of development first provided low cost public infrastructure-based services (water distribution, street cars, etc.) and then evolved to greater and greater levels of private consumption. If the existing public infrastructure is maintained, Canadians could, when and if required, shift back to a greater reliance on tap water (or public transit) without any public health impacts and with reduced environmental impacts. Presently, in Cochabamba there is no safe alternative public infrastructure to rely upon.
Residents of Cochabamba, not needing to rely on bottled drinks, would have a greater proportion of incomes to devote to consumption of food an important concern in a country where incomes are a tenth or less than in Canada. According to Richard Lewontin, the single most significant factor resulting in improved public health and increased longevity in the 1890s in Britain was the increase in the average industrial wage which permitted working class families to spend more on food (Biology as Ideology: The Doctrine of DNA, R. C. Lewontin, Anansi Press, 1991). If poor Bolivians spent less to obtain potable drinking fluids, as they would if they received safe municipal drinking water, they would have more to spend on food.
This magazine (February 1989) has compared the cost of providing municipal tap water to the cost of other potable fluids, demonstrating that the provision of tap water is a major public benefit provided at a very low cost. The comparison is even more important in Bolivia, where the ratio of the cost of a 300 millilitre beverage to average weekly income is approximately one to 100, while in Canada it is approximately one to 1,000.
If a Bolivian worker, earning an average wage, consumed three beverages a day to partly satisfy potable fluid needs, 21% of their weekly salary would be used for this purpose. Clearly, this is not possible. Instead, the Bolivian worker must boil unsafe tap water, or worse, drink this water unboiled. Boiling water is an inconvenient, expensive and energy intensive way to treat water. By contrast, the Canadian worker, earning an average wage, can satisfy all potable water needs from safe municipal drinking water for pennies a day.
Conclusion
The discussion above suggests that it is worthwhile to examine Cochabamba's public works infrastructure and operating expenditures comprehensively, at a minimum examining the inter-related impacts, costs and benefits of MSW, water, wastewater and sewage. This more complete evaluation would also include an estimate of the total public expense of providing safe tap water compared to the existing public expense (including purchase prices of beverages and waste management costs) of distributing potable drinking fluids in disposable beverage containers.
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