Presentation on theme: "Chapter 19 (pgs 304-321) Land Pollution. Garbage Barge 1987 – barge left N.Y. with 2899 metric tons of garbage Being brought to a landfill in North Carolina."— Presentation transcript:
Chapter 19 (pgs ) Land Pollution
Garbage Barge 1987 – barge left N.Y. with 2899 metric tons of garbage Being brought to a landfill in North Carolina Cargo was rejected in North Carolina, Florida, Alabama, etc Barge sailed around for 5 months until it finally came back to Brooklyn, N.Y and garbage was incinerated Problem: What can we do with all the garbage we create??
Section 19.1 Solid Wastes Objectives: List examples of solid wastes, and identify their sources. Identify past and present methods used to dispose of solid wastes. Think Critically Every community is faced with the NIMBY syndrome. The human population continues to grow, and garbage production continues to increase. Where can garbage be disposed without placing it in somebody’s backyard?
Solid Waste Solid Waste: Definition - all garbage, refuse, and sludge products from agriculture, forestry, mining, and municipalities. In other words – garbage, trash, refuse, junk, scrap, and sewage that need to be disposed of in a way that does not pollute the land.
Garbage Disposal Hunter-gatherers start to build cities – garbage disposal becomes a problem. 500 B.C. – Athens, Greece passed laws that resulted in the 1 st garbage dump Can no longer dump garbage in the streets All garbage had to be placed no closer than 1.6 km from city walls 1892 – NYC had outbreaks of typhus and cholera Garbage collected from streets, put on barges, dumped in ocean Ocean became polluted Build 1 st landfill – wastes are disposed by burying them
Landfill Problem Open Landfills – choose a site and truck in tons of garbage Supported large populations of rats, flies, roaches, etc Gave off foul odors Rainfall carried pollutants from garbage into the soil and water Now illegal in most states
Landfill Problem Sanitary Landfills – wastes are spread out in layers, compacted by bulldozers, covered with soil – repeat until a certain height, close landfill and plant grass and trees Decomposition of wastes produces methane gas – highly flammable and explosive Leaching of toxic substances into land and water New landfills must place a double liner around the area to prevent leaching
Check For Understanding 1. What are solid wastes? 2. What are some ways that people have disposed of solid wastes? 3. How might placing a landfill near an aquatic ecosystem be harmful to the organisms living in the water?
Section 19.2 Hazardous Wastes Objectives: Identify problems associated with hazardous wastes. Classify hazardous wastes according to their characteristics. Think Critically During the summer of 1990, the shorefront waters along the east coast of the U.S. became littered with medical wastes. Used syringes and blood vials containing blood infected with HIV and hepatitis B were found. Where could this have come from?
Effects of Hazardous Materials Hazardous Wastes – solid, liquid, or gaseous wastes that are potentially harmful to humans and the environment, even in low concentrations Love Canal – community in N.Y. where homes were built next to an old chemical waste dump and an elementary school and playground were built right on top of the dump Birth defects and cancer Cleanup and relocation of more than 1000 families cost the government > $190 million dollars. Now considered to be safe – would you move there?
Effects of Hazardous Materials Bhopal, India – toxic gas escaped from a storage tank at the Union Carbide company More than 3,600 people died 200,000 people were injured Accident left more than 2,500 people with permanent disabilities to their eyes, lungs, and reproductive systems Company paid $470 million to the people of Bhopal
Classification of Hazardous Wastes EPA (environmental protection agency) – has classified: Reactive Wastes – Wastes that can explode such as certain chemicals and gunpowder Corrosive Wastes – Wastes that can eat through steel and other substances such as acids and lye Ignitable Wastes – Wastes that can burst into flames at low temperatures such as paint thinners, oils, and cleaning fluids Toxic Wastes – Wastes that are poisonous to people and cause health problems (birth defects and cancer) such as arsenic, cyanide, mercury, and some pesticides Radioactive Wastes – Wastes that give off radioactivity and can cause skin burns, and destroy body cells and tissues Medical Wastes – old medicines, lab equipment, specimens, syringes, and blood vials
Check For Understanding 1. What are hazardous wastes? 2. In what category of hazardous wastes are substances containing mercury or cyanide classified? 3. Name 5 products in your home that contain hazardous materials and would require careful disposal?
Issues – The Wismut Mines Read page 311 in your textbook Answer decision questions on a sheet of paper and hand in before you leave class.
Section 19.3 Topsoil Erosion Objectives: Identify ways in which soil is lost. Describe the methods used in agriculture to prevent soil erosion Think Critically Along with the loss of topsoil, soil nutrients (nitrogen and phosphorus) are also lost. What do farmers do to counteract this? Why might this be a problem?
Topsoil Erosion Soil is cycled in the environment Mechanical and chemical weathering form new soil Erosion carries soil away Wind and water are the major causes of erosion
Desertification Soil becomes unsuitable for planting crops and sustaining livestock Caused by overgrazing, deforestation, and poor irrigation and cultivation practices Occurs mostly in dry regions that border deserts Has occurred on 30% of earth’s land In U.S. Arizona, Colorado, California and Texas are at risk
Soil Conservation/Land Management Strip-cropping – farmland is plowed so that plowed strips are separated by planted strips – reduces soil erosion. Contour Farming – method of plowing along a slope instead of across it. Furrows between rows of crops collect water, preventing soil erosion.
Soil Conservation/Land Management Terracing – a series of platforms called terraces are built into the slope of a hill, separated by vertical steps. This slows water flow and water can sink into the soil. Shelter Belts – rows of trees planted along the outer edges of a field as a windbreak. Reduces erosion by wind.
Check For Understanding 1. What is strip-cropping? 2. What types of practices lead to desertification? 3. How will the loss of major water resources in the High Plains region of Texas change the way agriculture is managed?
Section 19.4 Controlling Land Pollution Objectives: Identify and explain four methods for reducing the volume of wastes. Discuss the benefits and drawbacks of various forms of waste disposal. Think Critically Currently, many hazardous and solid wastes are exported from wealthier communities/nations to poorer ones. The wealthy area gets rid of their waste and the poor area gets paid. What are your opinions on this practice?
Disposable Society What are some disposable items we use daily? Could they be replaced by reusable items? Recycling programs – paper, metal, glass, and plastic are sorted from garbage, collected, and kept out of landfills Biodegradable – substances that decompose easily and enrich the soil. Natural recycling – grass, leaves, etc. Compost Pile – plant and food wastes are collected to make humus and fertilize soil
Disposing of Hazardous Wastes Waste Exchange – Sometimes waste materials from one process can be used in production of other products. First company avoids cost of waste disposal, second company purchases material at a reduced price. Deep-well Injection – Liquid wastes are pumped into deep porous rocks through lined pipes. Used by petroleum industry.
Disposing of Hazardous Wastes Secure Chemical Landfill – Constructed in an area of nonporous bedrock that prevents the leaching of pollutants into the groundwater. Controlled Incineration – Burning of wastes at extremely high temperature. Complete burning destroys hazardous wastes, but most expensive.
Disposing of Hazardous Wastes Chemical and Biological Treatment Plants – Certain chemical or biological reactions can neutralize hazardous wastes and then they can be disposed of safely. Radioactive Waste Disposal – Placed in water and sealed in stainless steel tanks. Tanks are encased in concrete and placed in concrete vaults underground.
Legislation EPA – environmental protection agency – established in 970 to protect the environment. Superfund – law passed in 1980 to protect communities from hazardous wastes. Makes polluters pay for cleanup and developed a priorities list. Foreign countries also joining in: France and Denmark giving grants to companies to research and use cleaner methods of technology.
Check For Understanding 1. What is a secure chemical landfill? 2. In what ways can controlled incineration affect the environment? 3. Why do you think that hazardous wastes from the U.S. end up in developing nations?