Presentation on theme: "All rivers in Alabama flow to the Gulf of Mexico.."— Presentation transcript:
All rivers in Alabama flow to the Gulf of Mexico.
Bellringer What is “water pollution”? Is a cup of coffee polluted water? Is a muddy stream polluted? “Can I Drink the Water?” The tap A spring or well A mountain stream A nearby creek or lake A drainage ditch after a heavy rain
Water Pollution Section 11.3 Objectives: 1.. 1. Classifying sources of water pollution as point and nonpoint. 2. 2. Identify major contaminants in water resulting from natural phenomena, homes, industry, and agriculture. 3. 3. Describing the eutrophication of water by industrial effluents and agricultural runoffs.
Water Pollution: Def: The introduction of chemical, physical, or biological agents into water that degrade water quality and adversely affect the organisms that depend on the water. Almost all of the ways we use water pollute it.
Two Types of Pollution Sources 1. 1. Point source pollution – discharged from a single source Septic tanks Unlined landfills Leaking storage tanks Polluted water from mines Industries Waste-water treatment plants Leaking oil tankers
Two Types of Pollution Sources (cont.) 2. Nonpoint source pollution – many different sources; hard to identify Chemical runoff from roadways Runoff from city streets Pesticides and other chemicals from lawns, golf courses, and farmland Runoff from livestock feedlots Rain containing air pollutants Runoff from farms and construction sites Oil and gas from personal watercraft
Point or Nonpoint? The Trucking Company in last week’s Pollution Tracking activity Parking lot runoff Untreated sewage Runoff from feedlots A restaurant’s drainage pipe emptying runoff into a river The litter in storm runoff Acid precipitation
Wastewater Treatment Compare to steps in Section 11.2 notes Primary Treatment: 1. 1. Filtration – ??? 2. 2. First settling tank - smaller particles settle to the bottom of the tank and from sewage sludge Secondary Treatment: 3. 3. Aeration – wastewater mixed with oxygen and bacteria 4. 4. Second settling tank – 5. 5. Chlorination – chlorine added to water
Wastewater Not all harmful substances are removed in wastewater treatment plants. Crytosporidium outbreak (1993, Milwaukee) Waterborne parasite that causes flulike symptoms 100 deaths; 400,000 sickened Outbreak probably caused by heavy rainfall and agricultural runoff overburdening treatment plants (OXFORD!)
Wastewater (cont.) Sewage sludge – Def.: solid material left AFTER treatment MAY be hazardous waste if high concentrations of toxic chemicals are present May be incinerated, then ashes buried in a secure landfill (EXPENSIVE) Possible uses: fertilizer, combine with clay to make building bricks
Artificial Eutrophication “Too much of a good thing is not a good thing.” Mineral nutrients are needed in aquatic ecosystems. Eutrophication: Natural process Too many decaying organisms use up oxygen in the water. The organisms living in the water change, and eventually the water body fills in.
Artificial Eutrophication (cont.) The natural process is accelerated when phosphorous and nitrogen are introduced by: Fertilizers – largest source Sewage Phosphates from detergents
Thermal Pollution Can be caused by power plants and industries using water for cooling systems. Increased temperatures cause lower oxygen levels.
Groundwater Pollution Anything that can seep into the groundwater can pollute it! Common pollutants: Pesticides and herbicides Fertilizers Petroleum products – gasoline and heating fuels from leaking underground storage tanks Remember, groundwater recharges VERY SLOWLY. Decontamination also can take HUNDREDS of years.
Ocean Pollution Causes? Cruise ships can legally dump wastewater and garbage in some parts. 85% from land activities Oil spills – dramatic, but responsible for only 5% of oil pollution in the ocean 1989 – Exxon Valdez – Alaska 2001 – Galapagos Islands 37 million gallons each year; land runoff of oil accounts for 200-300 million gallons/year!
Cleaning Up Water Pollution Clean Water Act (1972) Goal: to make all surface water clean enough for fishing and swimming by 1983 30% more lakes and rivers are now suitable for swimming and fishing Marine Protection, Research, and Sanctuaries Act (1972) – strengthened laws against ocean dumping Safe Drinking Water Act (1975) – public right-to-know laws Oil Pollution Act (1990) – requires all oil tankers in U.S. waters to have double hulls by 2015