A landfill, such as the North Wake County Landfill, must be open and available every day. Customers are typically municipalities and construction/demolition companies, although residents may also use the landfill. A layout of a typical landfill with supporting structures is shown in Figure 4.
Near the entrance of the the site is a recycling center where residents can drop off recyclable materials (aluminum cans, glass bottles, newspapers, blend paper, corrugated cardboard). This helps to reduce the amount of material in the landfill. Some of these materials are banned from landfills by law because they can be recycled.
As customers enter the site, their trucks are weighed at the scale house. Customers are charged tipping fees for using the site. The tipping fees vary from $10 to $40 per ton. These fees are used to pay for bonds or operation costs. The North Wake County Landfill has an operating budget of approximately $4.5 million, and part of that comes from tipping fees.
Along the site, there are drop-off stations for materials that are not wanted or legally banned by the landfill. A multi-material drop-off station is used for tires, motor oil, lead-acid batteries and drywall. Some of these materials can be recycled.
In addition, there is a household hazardous waste drop-off station for chemicals (paints, pesticides, other chemicals) that are banned from the landfill. These chemicals are disposed by private companies. Some paints can be recycled and some organic chemicals can be burned in incinerators or power plants.
Other structures alongside the landfill are the borrowed area that supplies the soil for the landfill, the runoff collection pond, leachate collection ponds, and methane station.
Landfills are complicated structures that, when properly designed and managed, serve an important purpose. In the future, new technologies called bioreactors will be used to speed the breakdown of trash in landfills and produce more methane.
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More Great Links
- U.S. Environmental Protection Agency's Municipal Solid Waste Handbook Online
- Annenberg/CPB Exhibit: Garbage
- Rotten Truth About Garbage
- Inspect a Landfill
- U.S. Environmental Protection Agency's Landfill Methane Outreach Program
- Bioreactor Landfill Demonstration Project
- U.S. Environmental Protection Agency's Office of Solid Waste: Kids Site
- Exploration of Landfill Leachate: Laboratory Project
- Leachate Treatment
- Santek Environmental: Landfill Solutions
- U.S. Environmental Protection Agency's Landfill Methane Outreach Program: FAQ
- Some Landfill Facts
- Primer on Landfill Gas as "Green" Energy
- Landfill Gas: Introduction
- Planet Green
- "Municipal Solid Waste." Environmental Protection Agency. Jan. 3, 2008. (Aug. 21, 2008)http://www.epa.gov/garbage/facts.htm
Our thanks to Marshall Parrish, education specialist, and Ivan Dickey, solid waste inspector, of Wake County Solid Waste Management Division, Raleigh, N.C., for the tour of the landfill and their advice in the preparation of this article.