Living in the Environment Water Pollution G. Tyler Miller’s Living in the Environment Chapter 20
Types and Sources of Water Pollution Point sources Nonpoint sources Water Quality Good 8-9 Do (ppm) at 20˚C Slightly polluted Moderately Heavily Gravely 6.7-8 4.5-6.7 Below 4.5 Below 4 Biological oxygen demand Water quality indication of what beneficial uses of water- spawning, recreation, swimming,drinking. Water quality Pg. 535
Point and Nonpoint Sources Urban streets Suburban development Wastewater treatment plant Rural homes Cropland Factory Animal feedlot POINT SOURCES
Water pollution Bacteria,Viruses,Protozoa, Parasitic worms Oxygen demanding substances Inorganic plant nutrients Organic chemicals Sediment or suspended matter Thermal pollution Genetic pollution Bacteria viruses Eat oxygen, phosphates, heat, introduction of non native species Table 19-2 tells all the things from bacteria,…vomiting, diarreha,dehydration
Biological Magnification Rainbow smelt 1.04 ppm Zooplankton 0.123 ppm Phytoplankton 0.0025 ppm Water 0.000002 ppm Herring gull 124 ppm Lake trout 4.83 ppm Herring gull eggs Why we need good water quality. Higher in food chain means more concentrated is contamination. Where are we on the food chain. Why Audobuan society devotes money to water quality. To protect birds.
Pollution of Streams Oxygen sag curve Fig. 20-5
Pollution of Lakes Eutrophication Aging of lakes Fig .22.7, p. 499 Discharge of untreated municipal sewage (nitrates and phosphates) Nitrogen compounds produced by cars and factories Discharge of treated (primary and secondary treatment: nitrates and phosphates) Discharge of detergents ( phosphates) Natural runoff (nitrates and phosphates Manure runoff From feedlots Phosphates, ammonia) Dissolving of nitrogen oxides (from internal combustion engines and furnaces) Runoff and erosion (from from cultivation, mining, construction, and poor land use) Runoff from streets, lawns, and construction lots (nitrates and phosphates) Lake ecosystem nutrient overload and breakdown of chemical cycling Aging of lakes Fig .22.7, p. 499
Solutions to better water quality Drainage Area Management Plans Agriculture plots 1987 Water Quality Act DAMP- street sweeping, stenciling, public education- Agriculture plots not on steep slope leads to water or have some sort of buffer zone. 1987 Water Quality Act--Main goals to make U.S. waters safe for fishing and swimming. Restore and maintain the chemical, physical, and biological integrity of nations waters. 1995 EPA developed discharge trading policy. Much like the sulfur dioxide trading policy for air pollution. Industrial plants to sell excess credits. Good news--Fishable and swimmable 36%®62% bad news-antiquated sewage systems--Earth Tech fund--build and maintain.
Contaminant plume moves with the groundwater Leaking tank Aquifer Water table Bedrock Figure 21.8 Natural capital degradation: groundwater contamination from a leaking gasoline tank. As the contaminated water spreads from its source in a widening plume, it can be extracted by wells used to provide water for drinking and irrigation. Groundwater flow Free gasoline dissolves in groundwater (dissolved phase) Gasoline leakage plume (liquid phase) Migrating vapor phase Water well Contaminant plume moves with the groundwater Fig. 20-12
Groundwater Pollution: Causes Hazardous waste injection well Pesticides Coal strip mine runoff De-icing road salt Buried gasoline and solvent tank Pumping well Cesspool septic tank Gasoline station Waste lagoon Water pumping well Sewer Landfill Leakage from faulty casing Accidental spills Discharge Unconfined freshwater aquifer Confined aquifer Confined freshwater aquifer Groundwater flow Fig. 20-11
Groundwater Pollution Prevention Monitoring aquifers Strictly regulating hazardous waste disposal Storing hazardous materials above ground
Fig. 20-15 Industry Nitrogen oxides from autos and smokestacks, toxic chemicals, and heavy metals in effluents flow into bays and estuaries. Cities Toxic metals and oil from streets and parking lots pollute waters; Urban sprawl Bacteria and viruses from sewers and septic tanks contaminate shellfish beds Construction sites Sediments are washed into waterways, choking fish and plants, clouding waters, and blocking sunlight. Farms Runoff of pesticides, manure, and fertilizers adds toxins and excess nitrogen and phosphorus. Red tides Excess nitrogen causes explosive growth of toxicmicroscopic algae, poisoning fish and marine mammals. Closed shellfish beds Closed beach Oxygen-depleted zone Toxic sediments Chemicals and toxic metals contaminate shellfish beds, kill spawning fish, and accumulate in the tissues of bottom feeders. Figure 21.10 Natural capital degradation: residential areas, factories, and farms all contribute to the pollution of coastal waters and bays. According to the UN Environment Programme, coastal water pollution costs the world $16 billion annually—$731,000 a minute—due to ill health and premature death. Stop 10:30 Oxygen-depleted zone Sedimentation and algae overgrowth reduce sunlight, kill beneficial sea grasses, use up oxygen, and degrade habitat. Healthy zone Clear, oxygen-rich waters promote growth of plankton and sea grasses, and support fish. Fig. 20-15 Fig. 21-10, p. 505
Reducing Water Pollution through Sewage Treatment Primary and Secondary sewage treatment. Figure 20-19
Technological Approach: Using Wetlands to Treat Sewage ( 45 centimeter layer of limestone gravel coated with decomposing bacteria First concrete pool Second concrete pool Sewage Wetland type plants Treated water
Global Outlook: Stream Pollution in Developing Countries Water in many of central China's rivers are greenish black from uncontrolled pollution by thousands of factories. Figure 20-7
Case Study: India’s Ganges River: Religion, Poverty, and Health Religious beliefs, cultural traditions, poverty, and a large population interact to cause severe pollution of the Ganges River in India. Very little of the sewage is treated. Hindu believe in cremating the dead to free the soul and throwing the ashes in the holy Ganges. Some are too poor to afford the wood to fully cremate. Decomposing bodies promote disease and depletes DO.
Case Study: India’s Ganges River: Religion, Poverty, and Health Daily, more than 1 million Hindus in India bathe, drink from, or carry out religious ceremonies in the highly polluted Ganges River. Stop 1:00
Drinking Water Quality Bottled water Safe Drinking Water Act EPA established national drinking water standards called maximum contaminant levels– System of Long Beach- groundwater pumped to Redondo and spring, treated, pumped back out to residences. Usually most safe because it is tested. Privately owned wells are not required to meet test standards. 1/3 of bottled water contaminated with bacteria- not required to do testing. Not required to test like federal government- IBWA International bottle water association. 7 million illnesses and 1200 deaths in the U.S. per year . Maximum contaminant levels
Is Bottled Water the Answer? Some bottled water is not as pure as tap water and costs much more. 1.4 million metric tons of plastic bottles are thrown away. Fossil fuels are used to make plastic bottles. The oil used to produce plastic bottles in the U.S. each year would fuel 100,000 cars.
Using Laws to Protect Drinking Water The U.N. estimates that 5.6 million Americans drink water that does not meet EPA standards. 1 in 5 Americans drinks water from a treatment plant that violated one or more safety standard.
• Minimize your use of pesticides. What Can You Do? Water Pollution • Fertilize garden and yard plants with manure or compost instead of commercial inorganic fertilizer. • Minimize your use of pesticides. • Do not apply fertilizer or pesticides near a body of water. • Grow or buy organic foods. • Do not drink bottled water unless tests show that your tap water is contaminated. Merely refill and reuse plastic bottles with tap water. • Compost your food wastes. Figure 21.19 Individuals matter: ways to help reduce water pollution. QUESTION: Which three of these actions do you think are the most important? • Do not use water fresheners in toilets. • Do not flush unwanted medicines down the toilet. • Do not pour pesticides, paints, solvents, oil, antifreeze, or other products containing harmful chemicals down the drain or onto the ground.
Roger Rosenblatt It is a hard truth to swallow, but nature does not care if we live or die. We cannot survive without the oceans, for example, but they can do just fine without us. End chapter 20