Water Pollution

What is water pollution? Any chemical, biological, or physical change in water quality that has a harmful effect on living organisms or makes water unsuitable for desired usage.

Water Pollution Statistics WHO: 3.4 million premature deaths each year from waterborne diseases 1.9 million from diarrhea U.S. 1.5 million illnesses 1993 Milwaukee 370,000 sick

What causes our water to be polluted? Infectious Agents: - bacteria and viruses often from animal wastes Oxygen Demanding Wastes: - organic waste that needs oxygen often from animal waste, paper mills and food processing. Inorganic Chemicals: - Acids and toxic chemicals often from runoff, industries and household cleaners Organic Chemicals: - oil, gasoline, plastics, detergents often from surface runoff, industries and cleaners

What causes our water to be polluted? Plant Nutrients: - water soluble nitrates, ammonia and phosphates often from sewage, agriculture and urban fertilizers Sediment: - soils and silts from land erosion can disrupt photosynthesis, destroy spawning grounds, clog rivers and streams Heat Pollution and Radioactivity: mostly from power plants

Sources of Water Pollution Point sources Nonpoint sources Water quality

Point and Nonpoint Sources Urban streets Suburban development Wastewater treatment plant Rural homes Cropland Factory Animal feedlot POINT SOURCES Fig. 22-4 p. 494

Point and Nonpoint Sources Point Source Pollution: - There is one major source of the pollution and it can be identified. - Examples: Pipe coming out of a factory directly into a river. Nonpoint Source Pollution: - There can be many sources for a body of water being polluted. - Example: A river being polluted due to urban runoff.

Major Sources of Water Pollution Agriculture:(A.K.A: Farms) Sediment: Heavy rains cause soil erosion. Fertilizers and Herbicides: Farmers use these on their crops for bug and weed control. They runoff during rain. Bacteria from livestock: Animals use the land as their bathroom. Their feces contains nitrates which pollute river during rain runoff. Salt from soil irrigation

Major Sources of Water Pollution Industrial: Clearing of land for businesses to be built can cause soil erosion. Waste and sewage dumping by factories. Big power plants use rivers, streams, and lakes to dispose of waste heat. Fort Meyers, Florida Manatee Park http://www.leeparks.org/panorama s/panoramas-parks-i- n.html#manatee Factories dump toxic or radioactive materials. Burning fuels causes “acid rain”.

Major Sources of Water Pollution Home: Sewage and septic leak in water source. Fertilizers, herbicides, pesticides used for lawn maintenance. Putting hazardous chemicals down the drain. Oil and antifreeze leak from cars onto the driveway.

The Story of Two Worlds Developed Countries U.S. and other developed countries sharply reduced point sources even with population and economic growth Nonpoint still a problem Toxic chemicals still problem Success Cuyahoga River, Thames River

The Story of Two Worlds Developing Countries: Serious and growing problem Half of world’s 500 major rivers heavily polluted Sewage treatment minimal $$$ Law enforcement difficult 10% of sewage in China treated Economic growth with little $$$ to clean up

India’s Ganges River Holy River (1 million take daily holy dip) 350 million (1/3rd of pop) live in watershed Little sewage treatment Used for bathing, drinking etc. Bodies (cremated or not) thrown in river Good news is the Indian government is beginning to work on problem

What laws govern water pollution in the United States? Most developed countries use laws to set water pollution standards. Federal Water Pollution Control Act (Clean Water Act 1972, ’77, ’87) Regulates navigable waterways..streams, wetlands, rivers, lake

Clean Water Act Sets standards for key pollutants Requires permits for discharge Requires sewage treatment Require permits for wetland destruction Does not deal with nonpoint sources well Goal All Waterways fishable and swimable

The Good News Between 1972 – 2002 fishable and swimmable streams 36% to 60% 74% served by sewage treatment Wetlands loss dropped by 80% Topsoil losses dropped by 1 billion tons annually

The Bad News 45% of Lakes, 40% streams still not fishable and swimmable Nonpoint sources still huge problem Livestock and Ag. Runoff Fish with toxins

Waste and Drinking Water How is waste water cleaned? How is drinking water purified? High tech way. How can we purify drinking water in developing nations? Is bottled water a good answer or an expensive rip-off? How do sewage treatment plants work? Waste and Drinking Water

How is waste water treated? Septic Systems ¼ of all U.S. homes have Septic tanks Septic tanks are used primarily outside city limits. How does it work? The Septic Tank — A septic tank's purpose is to separate solids from the wastewater, store and partially decompose as much solid material as possible, while allowing the liquid (or effluent) to go to the drainfield. ...more The Drainfield — After solids settle in the septic tank, the liquid wastewater (or effluent) is discharged to the drainfield, also known as an absorption or leach field. ...more The Soil — The soil below the drainfield provides the final treatment and disposal of the septic tank effluent. After the wastewater has passed into the soil, organisms in the soil treat the effluent before it percolates downward and outward, eventually entering ground or surface water. The type of soil also impacts the effectiveness of the drainfield; for instance, clay soils may be too tight to allow much wastewater to pass through and gravelly soil may be too coarse to provide much treatment. Fig. 22-15 p. 510

Technological Approach: Sewage Treatment Sewage Treatment Plant http://www.sandiego.gov/mwwd/general/kids/learnit/virtualsewage.shtml

Technological Approach: Using Wetlands to Treat Sewage Fig. 22-18 p. 513

Purification of rural drinking water There can be simple ways to purify water: Exposing to heat and UV rays Fine cloths to filter water Add small amounts of chlorine