WASTE DISPOSAL. Global `garbage glut' threatens landfills

More than half the cities in the United States will exhaust their existing landfills by the end of this decade, according to an international environmental group. ``What we're finding is that there is no real `away' for a throwaway society,'' says Cynthia Pollock, author of the report by the Washington-based Worldwatch Institute. The report points to a global ``garbage glut'' that is being compounded by growing populations, rising incomes, and changing consumption patterns in many parts of the world.

The problem is especially acute in cities located in densely populated regions. For example, Philadelphia - its own landfills full - is sending trash as far away as Ohio and southern Virginia to be buried.

Since 1980, that city's disposal costs have shot from $20 to $90 a ton, and it is now negotiating a trash export deal with the island of Curacao in the Netherlands Antilles.

Similar patterns are emerging in other US cities as the siting of new landfills becomes more expensive and politically unacceptable. Past disposal practices have sometimes lead to the contamination of groundwater and other problems.

Many countries are developing incinerators and waste-to-energy technologies as an alternative to land burial. Some 350 waste-to-energy plants are operating in Brazil, Japan, the Soviet Union, and various nations in Western Europe, which has about half the total.

But such techniques may have as many problems as traditional landfills, the report says. Incinerator ash, for instance, has sometimes been found to contain materials that are classified as hazardous.

``Recycling offers communities everywhere the opportunity to trim their waste disposal needs - and thereby reduce disposal costs,'' author Pollock says.

Indeed, recycling rates for aluminum, glass, and paper are on the upswing in many countries. In the last decade, Austria has tripled, and Japan more than doubled, their aluminum recycling rates. Since 1981, more than half the 300 billion aluminum cans sold in the US have been returned for recycling.

Despite such positive signs, the report says much more could be done. Government subsidies still make land disposal and incineration relatively cheap in the US. Meanwhile, the introduction of new plastics, especially in food packaging, could make recycling more difficult.

Developing countries face special challenges. In Mexico City most of the 10,000 tons of trash collected daily was left in open dumps until recently. In other burgeoning cities, municipal trash collection is being severely strained as the volume of trash generated grows at rates as high as 10 percent a year.