1. DO NOW: What do we do with all the garbage we generate?

2. Population and Waste It is getting harder to dispose of the waste we create – human population continues to grow – available land decreases. Today, the average person living in the United States produces 4.4 pounds of solid waste per day. Multiply that by 344 million people – that’s a lot of garbage.

3. Not All Wastes Are Equal Wastes are made from two basic materials: biodegradable materials nonbiodegradable materials A biodegradable material is a material that can be broken down by biological processes. Nonbiodegradable material cannot be broken down by biological processes.

4. Not All Wastes Are Equal Biodegradable – Plant and animal matter – Products made from natural materials newspapers, paper bags, cotton fibers, leather Nonbiodegradable – Synthetic compounds polyester, nylon, plastic

5. Garbage Dump In the past we disposed of garbage in dumps – This led to many environmental problems Odors Scavengers (rats) Leachate (a liquid that has passed through solid waste)

7. Solid Waste Management Most solid waste sent to landfills Some incinerated 30% recycled (1970 6.6% recycled)

8. Landfills A landfill is an area of land or an excavation where wastes are placed for permanent disposal More than 50% of the municipal and manufacturing solid waste in the United States ends up in landfills

9. Parts of a Modern Landfill

10. Safeguarding Landfills The Resource Conservation and Recovery Act (RCRA -1976, updated1984) – requires new landfills be built with safeguards to reduce pollution problems new landfills must be lined with clay and a plastic liner must have systems for collecting and treating leachate must have vents to carry methane out of the landfill