(MUSIC) Joan Cartan-Hansen, Host: In 500 bce, the city of Athens started the first garbage dump.
It didn't last long.
People preferred to just dump their trash outside their homes.
And that's how we handled trash for thousands of years.
In the mid-18 hundreds, some trash was hauled to pig farms.
Pigs would eat the trash and then people would eat the fattened pigs.
Until pigs started dying from food-borne illnesses.
The first modern landfill opened in Fresno, California in 1937.
A modern sanitary landfill is regulated by the government.
It must be built away from wetlands, flood plans, and earthquake faults.
The landfill must of a liner overlaying at least two feet of compacted clay soil.
Landfill operators have to make sure harmful waste products aren't leaking into underground water supplies.
The trash at the landfill has to be compacted frequently and covered with soil.
That helps cut down on odor, insects, and rodents.
And each landfill can only hold so much.
Operators have to prepare to shut down and care for closed landfills.
And they have to find a new place to put your trash.
For more information about garbage, check out the Science Trek website.
You'll find it at science trek dot org