Solid Waste Any discarded material that is

not liquid or gas (junk mail, coffee grounds, junked cars, etc.)

* about 6 pound/person /day

Where does our trash go?

In 2007 almost 65% of the solid wastes produced in U.S. went to 2,500 sanitary landfills.

Sanitary Landfills– waste disposal facility where wastes are put in the ground and covered each day with a layer of soil.

* Safer than open dumps (habitat for obnoxious smell, flies & Rats).

Leachate – liquids that drain from landfill. Contains dissolved chemicals from decomposing garbage.

leachate can get into ground water, making nearby wells unsafe.

.

Methane Gas is formed when wastes decompose without oxygen.

can seep through ground and into basements of nearby homes: one spark can blow up a house.

“NIMBY” – not in my backyard attitude makes it difficult to find landfill sites.

Finding acceptable locations – clay soils, stable bedrock, far from aquifer.

EPA Regulations for landfills – effective 1993

synthetic or clay liners

collecting and treating leachate

monitoring for escaping methane gas ( install vent pipes for escaping gas)

Monitor ground and surface water

Sanitary Landfill Design

Incinerators – burn trash

17% of trash is burned in U.S.

Japan and Switzerland burn more than 50% of their trash.

Advantages of Burning Trash

Reduces the volume of waste by 90%

Provides energy – Waste to energy plants – burn wastes to produce steam for electricity.

Disadvantages of Burning Trash:

Polluting gases ( carcinogens)

Ash Disposal ( may contain heavy metals which are hazardous wastes, Ex. cadmium, mercury, lead)