1. Environmental Science Chapter 19 Section 1
Solid Waste
Environmental Science
Chapter 19 Section 1

2. The Generation of Waste
Solid waste
Any discarded solid material.
Includes everything from junk mail to coffee ground to cars.
The amount of solid waste each American produces every year has more than doubled since the 1960s.

3. The Generation of Waste
Space and Waste
Many towns are running out of space to dispose of the amounts of waste that people create.
Example: Islip, NY filled a barge with 3,200 tons of garbage and sailed off. Noone would accept the waste, so it returned and burned it down to 430 tons of ash and was buried.

4. The Generation of Waste
Population and Waste
The amount of waste we produce grows larger.
The amount of land available per person grows smaller.
Average person in the United States produces 4.4 pounds of solid waste per day.
Therefore, it is becoming more difficult to dispose of it all.

5. Not All Wastes Are Equal
Two main types of waste:
Biodegradable
Can be broken down by biological processes.
Examples: newspapers, paper bags, cotton fibers, leather.
Nonbiodegradable
Cannot be broken down by biological processes.
Examples: polyester and plastic.

6. Not All Wastes Are Equal
Plastic Problems
Plastics are made from petroleum or natural gas.
Consist mostly of carbon and hydrogen put together in molecular chains that are not found in nature.
Cannot be broken down by organisms yet, so may accumulate and last for hundreds of years.

7. Types of Solid Waste Municipal Solid Waste
The waste produced by households and businesses.
About 2% of the total solid waste.
More than 236 million tons each year.
Enough to fill a convoy of garbage trucks that would stretch around the Earth about six times.

8. Types of Solid Waste
Solid Waste from Manufacturing, Mining, and Agriculture
Make up most of the total solid waste produced in the United States.
Produced indirectly by consumers – we buy the products that have been mined or created.
Manufacturing waste – scrap metal, plastics, paper, sludge, and ash.
Mining waste – rocks and minerals that are left over.
Agricultural waste – crop waste and manure.

9. Solid Waste Management
Landfills
Permanent waste-disposal facility where wastes are put in the ground and covered each day with a layer of soil, plastic, or both.
More than 50% of municipal and manufacturing waste ends up here.

10. Solid Waste Management
Problems with Landfills
Leachate
A liquid that has passed through compacted waste in a landfill.
Forms when water seeps down through a landfill and collects dissolved chemicals from decomposing garbage.
Landfills usually have monitoring wells and storage tanks to store and measure leachate, which can then be treated as waste water.
Methane
Highly flammable gas produced by decomposing organic waste.
If not monitored, can seep through the ground and into basements of homes up to 300 m from the landfill.

11. Solid Waste Management
Safeguarding Landfills
Resource Conservation and Recovery Act
Passed in 1976 and updated in 1984.
Requires that new landfills be built with safeguards to reduce pollution problems.
Must be lined with clay and a plastic liner.
Must have systems for collecting and treating leachate.
Must have vent pipes for methane.

12. Solid Waste Management
Building More Landfills
Running out of space to build more landfills.
The materials are not decomposing as fast we are filling the landfills.

13. Solid Waste Management
Incinerators
Burn solid waste.
In 1999, the U.S. had 102 incinerators capable of burning up to 94,000 metric tons of municipal solid waste each day.
Incinerated materials take up less space, but may be more toxic.
Burning paints and chemicals can pollute the air.