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

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.

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.

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

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)

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

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

Parts of a Modern Landfill

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