1. WASTE Solid Waste

2. Objectives Name one characteristic that makes a material biodegradable. Name one characteristic that makes a material biodegradable. Identify two types of solid waste. Identify two types of solid waste. Describe how a modern landfill works. Describe how a modern landfill works. Name two environmental problems caused by landfills. Name two environmental problems caused by landfills.

3. The Generation of Waste Solid waste - any discarded solid material such as garbage, refuse, or sludges includes everything from junk mail to coffee grounds to cars includes everything from junk mail to coffee grounds to cars US makes 10+ billion metric tons of waste a year US makes 10+ billion metric tons of waste a year ~ more than doubled since the 1960s – products used once and then thrown away Many towns are running out of space to dispose of waste. Many towns are running out of space to dispose of waste. Why??? Why???

4. Population and Waste ~human population growing ~available land decreasing ~Where will waste go? ~Today, the average person in the US produces 4.4 pounds of solid waste per day.

5. Space and Waste In 1987, a barge was loaded with 3,200 tons of garbage and left the town of Islip, New York, in search of a place to unload its waste. In 1987, a barge was loaded with 3,200 tons of garbage and left the town of Islip, New York, in search of a place to unload its waste. The barge sailed for more than five months but no one would accept the garbage. The barge sailed for more than five months but no one would accept the garbage. The garbage was finally burned in New York, and the 430 tons of ash sent to Islip to be buried. The garbage was finally burned in New York, and the 430 tons of ash sent to Islip to be buried. Voyage of the Mobro 4000 | Retro Report | The New York Times

7. Not All Wastes Are Equal Wastes are made from two basic materials: biodegradable materials biodegradable materials nonbiodegradable materials. nonbiodegradable materials. biodegradable material - can be broken down (by bacteria) Ex.: natural materials – plant & animal matter, cotton, paper

8. Not All Wastes Are Equal Nonbiodegradable material - cannot be broken down may last for hundreds of years may last for hundreds of years Ex.: synthetic (man-made) materials like polyester, nylon, plastic and metals Ex.: synthetic (man-made) materials like polyester, nylon, plastic and metals

9. Plastic Problems Plastics are made from petroleum or natural gas, which consist mostly of carbon and hydrogen. Plastics are made from petroleum or natural gas, which consist mostly of carbon and hydrogen. Plastics combine these elements in molecular chains that are not found in nature. Plastics combine these elements in molecular chains that are not found in nature. Microorganisms have not developed ways to break down the molecular structures of most plastics. Microorganisms have not developed ways to break down the molecular structures of most plastics. Therefore, some plastics that we throw away may accumulate and last for hundreds of years. Therefore, some plastics that we throw away may accumulate and last for hundreds of years.

11. Municipal Solid Waste Municipal solid waste - waste produced by households and businesses what we throw out on a day-to-day basis what we throw out on a day-to-day basis growing very quickly growing very quickly creates more than 210 million metric tons of solid waste each year creates more than 210 million metric tons of solid waste each year only 2% of the total solid waste in the US only 2% of the total solid waste in the US

12. Solid Waste from Manufacturing, Mining, and Agriculture Consumers indirectly create manufacturing waste by purchasing products that have been manufactured. Consumers indirectly create manufacturing waste by purchasing products that have been manufactured. Mining wastes include rock and minerals that are left exposed in large heaps, dumped in oceans and rivers, or disposed by refilling and landscaping abandoned mines. Mining wastes include rock and minerals that are left exposed in large heaps, dumped in oceans and rivers, or disposed by refilling and landscaping abandoned mines.

13. Solid Waste from Manufacturing, Mining, and Agriculture Agricultural waste makes up 9% of the total solid waste but is biodegradable. Agricultural waste makes up 9% of the total solid waste but is biodegradable. The increased use of fertilizers and pesticides may cause agricultural waste to become more difficult to dispose of because the waste may be harmful if returned to the soil. The increased use of fertilizers and pesticides may cause agricultural waste to become more difficult to dispose of because the waste may be harmful if returned to the soil.

14. Landfills landfill - an area of land where wastes are placed for permanent disposal >50% of solid waste in the US ends up in landfills >50% of solid waste in the US ends up in landfills

15. Landfills Landfills must contain the waste that is buried inside and keep it from causing problems with the environment. Landfills must contain the waste that is buried inside and keep it from causing problems with the environment. Waste inside a landfill must not come into contact with the soil and groundwater surrounding the landfill. Waste inside a landfill must not come into contact with the soil and groundwater surrounding the landfill. Landfills are maintained by covering wastes each day with a layer of soil, plastic, or both. Landfills are maintained by covering wastes each day with a layer of soil, plastic, or both. Video Field Trip - Landfill

16. Problems with Landfills Leachate - liquid that has passed through solid waste may contain chemicals from paints, pesticides, cleansers, cans, batteries, and appliances may contain chemicals from paints, pesticides, cleansers, cans, batteries, and appliances can flow into groundwater supplies and make nearby wells unsafe to drink can flow into groundwater supplies and make nearby wells unsafe to drink

17. Problems with Landfills Methane - a highly flammable gas forms as organic wastes decompose forms as organic wastes decompose may seep through the ground and into basements of nearby homes and cause explosions may seep through the ground and into basements of nearby homes and cause explosions can be pumped out of landfills and burned to generate electricity can be pumped out of landfills and burned to generate electricity

18. How Does a Modern Landfill Work?

19. Safeguarding Landfills The Resource Conservation and Recovery Act passed in 1976 and updated in 1984 passed in 1976 and updated in 1984 requires that new landfills: requires that new landfills: 1)must be lined with clay and a plastic liner 2)must have systems for collecting and treating leachate 3)must have vents to carry methane out of the landfill Adding safeguards to landfills increases the cost of building them. Adding safeguards to landfills increases the cost of building them. Finding acceptable places to build landfills is difficult. Finding acceptable places to build landfills is difficult.

20. Building More Landfills currently running out of space to develop new landfills currently running out of space to develop new landfills materials are not decomposing as fast as we can fill landfills materials are not decomposing as fast as we can fill landfills # of active landfills in the US in 1988 was 8,000 # of active landfills in the US in 1988 was 8,000 by 1999, # of active landfills decreased to 2,300 by 1999, # of active landfills decreased to 2,300Why???? landfills have been filled to capacity

21. Building More Landfills The EPA estimates that active landfills in 20 states will be filled to capacity within 20 years.

22. Incinerators Incinerators - Incinerators - convert the waste into ash, gas, and heat Incinerated materials do not disappear, but the amount of solid waste is reduced. Incinerated materials can be more toxic than before. Special air pollution control devices help control the amount of toxins released into the air. small amounts of poisonous gases and particles of toxic heavy metals still released into the air.

23. Incinerators How a waste-to-energy plant works