Managing Munipipal Solid Waste

An urban community that is considering having its own waste management system needs to establish a framework for deciding how to manage Municipal Solid Waste (MSW) when it is generated. In doing so, it is important to make a clear distinction between prevention and management activities to ensure that adequate attention is focused on each. Prevention refers to activities by manufacturers (such as modifying products, including packaging, to reduce the toxicity or quantity of products before they are manufactured)--for example, the program proposed by the Canadian packaging society, in which they pledged to financially support the 540 municipal recycling programs in the Province of Ontario-- and by consumers (such as modifying purchasing decisions to buy products that are less toxic or more durable).

The motivation for promoting MSW prevention is strong. Reducing toxicity would make all management methods safer and could restore public confidence in waste management policies and programs. For example, reducing the amounts and types of organic chemicals in landfills would mean less air pollution (such as chemicals that contain volatile components) and less toxic leachate. Quantity reduction would mean that the useful life of existing and future waste management facilities would be extended and new replacement capacity could be developed at a slower rate.

Even assuming notable progress in waste prevention, communities will continue to generate large amounts of MSW requir

ed of two units, a 300MW unit and a 500MW united. Only the second unit has flue gas desulphurization (FGD). When the two units are operating at peak load, they discharge about 45 tonnes of dry ash per hour. In addition, the FGD scrubber on the second unit discharges some 50 tonnes of scrubber effluent per hour, containing 50 percent solids. This waste is going to be produced at about this rate for about 35 years, the expected life of the plant. A most responsible approach was adopted to the disposal of all this waste. A suitable landfill area was identified nearby, where clay overlay rock at shallow depths. The entire strata was free of major folding or faulting and the leachate is unlikely to find its way into the ground water. Suitable parameters were established both for the landfill area and the necessary reservoirs and ponds. An environmental impact study confirmed that there would be no problem in the disposal of the solids waste from the power plant throughout its useful life. The entire landfill disposal system, including site development and the treatment plant, cost approximately $30 million (U.S.). Such a comprehensive and careful approach to the problem is to be commended. Disposal of dry ash in this plant