Solid waste refers to any discarded material that is not liquid or gas, such as junk mail, coffee grounds, and junked cars. In 2007, about 65% of solid waste produced in the US went to sanitary landfills. Sanitary landfills are waste disposal facilities where trash is buried and covered with soil each day. Leachate from decomposing garbage in landfills can contaminate groundwater if not properly contained. Methane gas is also produced during decomposition and must be vented to prevent explosions. EPA regulations implemented in 1993 require landfills to have synthetic liners, collect and treat leachate, and monitor for methane gas.

2. Solid Waste
Any discarded material that is
not liquid or gas (junk mail,
coffee grounds, junked cars,
etc.)
* about 6 pound/person /day

3. Where does our trash go?
In 2007 almost 65% of the
solid wastes produced in
U.S. went to 2,500 sanitary
landfills.

4. Sanitary Landfills– waste disposal
facility where wastes are put in
the ground and covered each
day with a layer of soil.
* Saferthan open dumps (habitat
for obnoxious smell, flies &
Rats).

5. • Leachate – liquids that drain from
landfill. Contains dissolved
chemicals from decomposing
garbage.
• leachate can get into ground water,
making nearby wells unsafe.

6. .
• 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.

7.  “NIMBY” – not in my backyard
attitude makes it difficult to find
landfill sites.
 Finding acceptable locations –
clay soils, stable bedrock, far
from aquifer.

8. 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

9. Sanitary Landfill Design

10. •Incinerators – burn trash
•17% of trash is burned in
U.S.
•Japan and Switzerland burn
more than 50% of their trash.

11. Advantages of Burning Trash
•Reduces the volume of waste
by 90%
• Provides energy – Waste to
energy plants – burn wastes to
produce steam for electricity.

12. Disadvantages of Burning Trash:
Polluting gases ( carcinogens)
Ash Disposal ( may contain
heavy metals which are
hazardous wastes, Ex.
cadmium, mercury, lead)