FRANK BERNHEISEL

Your trash: What happens to it?

In 2010, Americans generated about 250 M tons of trash of which 29 M tons were burned for energy. About 65 M tons were recycled and used to manufacturer new products. Of the remainder, about 20 M tons, mostly yard waste, was composted and the remaining 55 percent disposed in landfills.

Today, most cities and counties in the US and Canada have recycling programs. The interest in recycling started about the time of the first Earth Day in 1970. In the early days, glass went in one bin, metals in a second, and newspaper in a brown paper grocery bag. A truck came by and the operators made additional separations as they put the items into the truck; green glass in the first compartment, brown glass, etc. Time-consuming and inefficient and besides, how many compartments can there be in a truck? Despite the problems, people wanted to recycle more materials.

This push for recycling came from citizens. In local governments, neither politicians nor public works staff wanted to do recycling. Their reason was that it cost more money; two collection trucks servicing every house instead of one. Trash collection already was the biggest part of the cost of solid waste management. In addition, there were few markets for the materials recovered. Recycling was a true grass roots movement.

Over time, several things changed. To improve the efficiency of collection programs began to adopt "dual stream" systems; all paper in one bin and cans and bottles in a second. This evolved into "single stream" collection; all recyclable materials in one container. Also, the number of materials recycled was increased. This and citizen convenience increased the total quantity recycled.

From 1990 to 2010, EPA reports that the recycling rate doubled from 16 percent to 34.1 percent. These changes allowed many communities, such as the City of Baltimore, to rationalize their collection; they reduced trash collection to once per week and increased recycling to once per week. Baltimore saved $9 M in the first year of the new operation.

Both dual and single stream collection require the materials be separated and prepared for shipment in industrial quantities. Newspaper, offices paper, and cardboard boxes need to be separated, because each has different characteristics and will be used by specific manufacturers; for example, old cardboard into new cardboard boxes, etc.

To be used in manufacturing the materials must be cleaned and compressed into bales for shipment. The bales weigh up to a ton, each. The processing plant that performs these functions is a materials recovery facility (MRF). The recovered materials from the MRFs at this point are termed "secondary materials." There are specifications for each type of material, which are published by the Institute of Scrap Recycling Industries (ISRI). The secondary materials are sold both by long-term contracts and on-the-spot market. And there are individual buyers for each material and futures are traded on the Chicago Mercantile Exchange and other markets. Many of the secondary materials buyers are overseas; China is a major purchaser of secondary materials.

The market price per ton varies with the individual material, for example

• aluminum cans -- $1,000
  
• shredded steel -- $400
  
• PET bottles -- $900
  old cardboard -- $120
  
• glass is essentially worthless

Recycling aluminum and many plastics uses only 10 percent of the energy needed to produce new aluminum and plastic from virgin materials. Recycling paper not only saves trees but reduces the energy required to make new paper by 65 percent. Recycling paper also reduces the water needed to make new paper by 7000 gallons per ton. Further, the use of secondary instead of virgin materials reduces the air pollution resulting from manufacturing.