Water Pollution.

Water Pollution

The Seattle, Washington Area, U.S.
Figure 20.1: The U.S. city of Seattle, Washington, was founded on the shore of Puget Sound and quickly expanded eastward toward Lake Washington. Fig. 20-1, p. 528

Core Case Study: Lake Washington
Sewage dumped into Lake Washington 1955: Edmondson discovered cyanobacteria in the lake Role of phosphorus – nutrient allowing the bacteria to grow. Public pressure led to cleanup of the lake Sewage treatment plant effluent diverted to Puget Sound Population growth bringing new challenges

Water Pollution Comes from Point and Nonpoint Sources (1)
Change in water quality that can harm organisms or make water unfit for human uses Usually caused by Contamination by chemicals Excessive heat Point sources Located at specific places Easy to identify, monitor, and regulate Examples Drain pipe, sewer line, etc.

Point Source of Polluted Water in Gargas, France
Figure 20.3: This point-source water pollution flows uncontrolled into a stream near Gargas, France. Fig. 20-3, p. 530

Broad, diffuse areas Difficult to identify and control Expensive to clean up Examples Runoff from farms, feedlots, urban streets, etc.

Leading causes of water pollution Agriculture activities Sediment eroded from the lands Fertilizers and pesticides Bacteria from livestock and food processing wastes Industrial facilities Growing problem with coal ash (an indestructible waste) Mining Erosion of sediment Runoff of toxic chemicals Human consumption plastics

Nonpoint Sediment from Unprotected Farmland Flows into Streams
Figure 20.4: Nonpoint sediment pollution eroded from farmland flows into streams and sometimes changes their courses or dams them up. As measured by weight, it is the largest source of water pollution. Question: What do you think the owner of this farm could have done to prevent such sediment pollution? Fig. 20-4, p. 530

Lake Polluted with Mining Wastes
Figure 20.5: The water in this lake is polluted with mining wastes. Fig. 20-5, p. 531

Plastic Wastes in Mountain Lake
Figure 20.6: Plastics and other forms of waste pollute this mountain lake as well as many bodies of water around the world, and can release harmful chemicals into the water. Fig. 20-6, p. 531

Major Water Pollutants Have Harmful Effects
Infectious disease organisms: contaminated drinking water The World Health Organization (WHO) 1.6 million people die every year, mostly under the age of 5 Not enough clean drinking water or enough water for adequate hygiene. Diarrhea – kills a child under 5 every 18 seconds

Major Water Pollutants and Their Sources
Table 20-1 Table 20-1, p. 532

Common Diseases Transmitted to Humans through Contaminated Drinking Water
Table 20-2 Table 20-2, p. 532

Science Focus: Testing Water for Pollutants (1)
Variety of tests to determine water quality Coliform bacteria: Escherichia coli, significant levels Safe levels: Drinking: no e. coli/100 ml Swimming: less than 200 colonies of e.coli/100 ml Level of dissolved oxygen (DO) Chemical analysis

Science Focus: Testing Water for Pollutants (2)
Indicator species Examples Bacteria and yeast glow in the presence of a particular toxic chemical Color and turbidity of the water

Water Quality as Measured by Dissolved Oxygen Content in Parts per Million
Figure 20.A: Scientists measure dissolved oxygen (DO) content in parts per million (ppm) at 20°C (68°F) as an indicator of water quality. Only a few fish species can survive in water with less than 4 ppm of dissolved oxygen at this temperature. Some warm-water species have evolved ways to tolerate low DO levels better than most cold-water species can. Question: Would you expect the dissolved oxygen content of polluted water to increase or decrease if the water is heated? Explain. Fig. 20-A, p. 533

Streams Can Cleanse Themselves If We Do Not Overload Them
Clean themselves of degradable, oxygen-demanding wastes through Dilution Biodegradation of wastes by bacteria takes time Process interrupted by: Overloading with pollutants Drought Damming Water diversion Does not remove slowly degrading or nondegradable wastes Oxygen sag curve The reduction of organisms with high oxygen demand until cleansed.

Dilution and Decay of Degradable, Oxygen-Demanding Wastes in a Stream
Figure 20.7: Natural capital. A stream can dilute and decay degradable, oxygen-demanding wastes, and it can also dilute heated water. This figure shows the oxygen sag curve (blue) and the curve of oxygen demand (red). Depending on flow rates and the amount of biodegradable pollutants, streams recover from oxygen-demanding wastes and from the injection of heated water if they are given enough time and are not overloaded (Concept 20-2a). See an animation based on this figure at CengageNOW™. Question: What would be the effect of putting another discharge pipe emitting biodegradable waste to the right of the one in this picture? Fig. 20-7, p. 534

Stream Pollution in More Developed Countries
1970s: Water pollution control laws Industries reduce or eliminate point source wastes Successful water clean-up stories Ohio Cuyahoga River, U.S. So polluted-it would catch on fire Thames River, Great Britain Flowing sewer Contamination of toxic inorganic and organic chemicals by industries and mines

Individuals Matter: The Man Who Planted Trees to Restore a Stream
John Beal: restoration of Hamm Creek, Seattle, WA, U.S. 1980- stream had no fish and all trees gone due to pollution Planted trees Persuaded companies to stop dumping Removed garbage

Global Outlook: Stream Pollution in Developing Countries
Half of the world’s 500 major rivers are polluted Most run through less developed countries Can not afford waste treatment plants No laws for controlling pollution According to Global Water Policy Project – 80-90% of developing countries dump untreated sewage directly into surface waters Untreated sewage Industrial waste India’s rivers 2/3 of water resources of polluted China’s rivers 2007 Report – 1.3 billion live without treated water

Natural Capital Degradation: Highly Polluted River in China
Figure 20.8: Natural capital degradation. This highly polluted river in central China has been turned greenish-black by uncontrolled pollution from thousands of factories. In some parts of China, river water is too toxic to touch, much less drink. The cleanup and modernization of Chinese cities such as Beijing and Shanghai are forcing polluting refineries and factories to move to rural areas where two-thirds of China’s population resides. Liver and stomach cancers, linked in some cases to water pollution, are among the leading causes of death in the countryside. Farmers too poor to buy bottled water must often drink polluted well water. Fig. 20-8, p. 535

Trash Truck Disposing of Garbage into a River in Peru
Figure 20.9: Global outlook: This garbage truck is dumping trash into a river in Peru. Fig. 20-9, p. 536

Too Little Mixing and Low Water Flow Makes Lakes Vulnerable to Water Pollution
Less effective at diluting pollutants than streams Stratified layers Little vertical mixing Little of no water flow Can take up to 100 years to change the water in a lake Biological magnification of pollutants

Lake Fish Killed by Water Pollution
Figure 20.10: Water pollution has killed the fish in this lake. Fig , p. 536

Cultural Eutrophication Is Too Much of a Good Thing (1)
Natural enrichment of a shallow lake, estuary, or slow-moving stream Caused by runoff into lake that contains nitrates and phosphates Oligotrophic lake Low nutrients, clear water

Nitrates and phosphates from human sources Farms, feedlots, streets, parking lots Fertilized lawns, mining sites, sewage plants During hot weather or droughts Algal blooms Increased bacteria More nutrients Anaerobic bacteria

Cultural Eutrophication of Chinese Lake
Figure 20.11: Global outlook: Severe cultural eutrophication has covered this lake near the Chinese city of Haozhou with algae. Fig , p. 537

Prevent or reduce cultural eutrophication Remove nitrates and phosphates (expensive) Banning or limiting use of nitrates/phosphates, etc. Soil conservation Clean up lakes Remove excess weeds Use herbicides and algaecides Pump in air (expensive, energy intensive)

Revisiting Lake Washington and Puget Sound
Severe water pollution can be reversed Citizen action combined with scientific research Good solutions may not work forever Wastewater treatment plant effluents sent into Puget Sound Now what’s happening? Need to reduce pop growth and resource use Healthy Puget Sound by 2020.

The Great Lakes of North America
Figure 20.12: The five Great Lakes of North America make up the world’s largest freshwater system. Dozens of major cities in the United States and Canada are located on their shores, and water pollution in the lakes is a growing problem. Fig , p. 538

Case Study: Pollution in the Great Lakes (1)
95% of US & 1/5 of World’s fresh surface water. 1960s: Many areas with cultural eutrophication Especially lake Erie 1972: Canada and the United States: Great Lakes pollution control program (Great Lakes Water Quality Agreement) Decreased algal blooms Increased dissolved oxygen Increased fishing catches Swimming beaches reopened Better sewage treatment plants Fewer industrial wastes Bans on phosphate-containing household products

Case Study: Pollution in the Great Lakes (2)
Problems still exist Raw sewage Nonpoint runoff of pesticides and fertilizers Biological pollution (invasive species) Atmospheric deposition of pesticides and Hg 2007 State of the Great Lakes report New pollutants found Wetland loss and degradation Declining of some native species Native carnivorous fish species declining

Ground Water Cannot Cleanse Itself Very Well (1)
Source of drinking water Common pollutants Fertilizers and pesticides Gasoline Organic solvents Pollutants dispersed in a widening plume (diffusion)

Ground Water Cannot Cleanse Itself Very Well (2)
Slower chemical reactions in groundwater due to Slow flow: contaminants not diluted Less dissolved oxygen Fewer decomposing bacteria Low temperatures

Leakage from faulty casing
Polluted air Hazardous waste injection well Pesticides and fertilizers Coal strip mine runoff Deicing road salt Buried gasoline and solvent tanks Cesspool, septic tank Pumping well Gasoline station Water pumping well Waste lagoon Sewer Landfill Accidental spills Leakage from faulty casing Figure 20.13: Natural capital degradation. These are the principal sources of groundwater contamination in the United States (Concept 20-3a). Another source in coastal areas is saltwater intrusion from excessive groundwater withdrawal. (Figure is not drawn to scale.) Question: What are three sources shown in this picture that might be affecting groundwater in your area? Discharge Freshwater aquifer Freshwater aquifer Freshwater aquifer Groundwater flow Fig , p. 540

Groundwater Pollution Is a Serious Hidden Threat in Some Areas
China: 90% of urban aquifers are contaminated or overexploited U.S.: FDA reports of toxins found in many aquifers Threats Gasoline, oil Nitrate ions Arsenic

Pollution Prevention Is the Only Effective Way to Protect Groundwater
1000s of years for contaminated ground water to cleanse itself of degradable pollution. Nondegradable stay forever. Prevent contamination of groundwater Cleanup: expensive and time consuming

Groundwater Pollution
Solutions Groundwater Pollution Prevention Cleanup Find substitutes for toxic chemicals Pump to surface, clean, and return to aquifer (very expensive) Keep toxic chemicals out of the environment Install monitoring wells near landfills and underground tanks Inject microorganisms to clean up contamination (less expensive but still costly) Require leak detectors on underground tanks Ban hazardous waste disposal in landfills and injection wells Figure 20.14: There are ways to prevent and ways to clean up contamination of groundwater but prevention is the only effective approach (Concept 20-3B). Questions: Which two of these preventive solutions do you think are the most important? Why? Store harmful liquids in aboveground tanks with leak detection and collection systems Pump nanoparticles of inorganic compounds to remove pollutants (still being developed) Fig , p. 541

There Are Many Ways to Purify Drinking Water
Reservoirs and purification plants Process sewer water to drinking water Expose clear plastic containers to sunlight (UV) Less developed countries The LifeStraw Inexpensive, portable water filter Aid agencies distribute in Africa PUR: chlorine and iron sulfate powder

The LifeStraw: Personal Water Purification Device
Figure 20.15: The LifeStraw™, designed by Torben Vestergaard Frandsen, is a personal water purification device that gives many poor people access to safe drinking water. Here, four young men in Uganda demonstrate its use. Question: Do you think the development of such devices should make prevention of water pollution less of a priority? Explain. Fig , p. 542

Case Study: Protecting Watersheds Instead of Building Water Purification Plants
New York City water Reservoirs in the Catskill Mountains Paid towns, farmers, and others in the watershed to restore forests, wetlands, and streams Saved the cost of building a plant: $6 billion

Using Laws to Protect Drinking Water Quality
1974: U.S. Safe Drinking Water Act Sets maximum contaminant levels for any pollutants that affect human health Health scientists: strengthen the law Water-polluting companies: weaken the law

Case Study: Is Bottled Water the Answer?
U.S.: some of the cleanest drinking water Bottled water Some from tap water 40% bacterial contamination Fuel cost to manufacture the plastic bottles Recycling of the plastic 240-10,000x the cost of tap water Growing back-to-the-tap movement

Ocean Pollution Is a Growing and Poorly Understood Problem (1)
2006: State of the Marine Environment 80% of marine pollution originates on land Sewage Coastal areas most affected Deeper ocean waters Dilution Dispersion Degradation

Ocean Pollution Is a Growing and Poorly Understood Problem (2)
Cruise line pollution: what is being dumped? U.S. coastal waters Raw sewage Sewage and agricultural runoff: NO3- and PO43- Harmful algal blooms Oxygen-depleted zones Huge mass of plastic in North Pacific Ocean Great Pacific Garbage Patch

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; sewage adds nitrogen and phosphorus. Urban sprawl Bacteria and viruses from sewers and septic tanks contaminate shellfish beds and close beaches; runoff of fertilizer from lawns adds nitrogen and phosphorus. 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 toxic microscopic algae, poisoning fish and marine mammals. Closed shellfish beds Closed beach Oxygen-depleted zone Figure 20.16: Natural capital degradation. Residential areas, factories, and farms all contribute to the pollution of coastal waters. According to the UN Environment Programme, coastal water pollution costs the world more than $30,000 a minute, primarily for health problems and premature deaths. Questions: What do you think are the three worst pollution problems shown here? For each one, how does it affect two or more of the ecological and economic services listed in Figure 8-5 (p. 172)? Toxic sediments Chemicals and toxic metals contaminate shellfish beds, kill spawning fish, and accumulate in the tissues of bottom feeders. 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 , p. 545

Science Focus: Oxygen Depletion in the Northern Gulf Of Mexico
Severe cultural eutrophication Oxygen-depleted zone Overfertilized coastal area Preventive measures Will it reach a tipping point?

A Large Zone of Oxygen-Depleted Water in the Gulf of Mexico Due to Algal Blooms
Figure 20.B: Natural capital degradation. A large zone of oxygen-depleted water (containing less than 2 ppm dissolved oxygen) forms each year in the Gulf of Mexico (lower right drawing) as a result of oxygen-depleting algal blooms caused primarily by high inputs of plant nutrients from the Mississippi River basin (top). The drawing (bottom left), based on a satellite image, shows how these inputs spread along the coast during the summer of In the image, reds and greens represent high concentrations of phytoplankton and river sediment. This problem is worsened by loss of wetlands, which would have filtered some of these plant nutrients. Question: Can you think of a product you used today that was directly connected to this sort of pollution? (Data from NASA) Fig. 20-B, p. 546

Ocean Pollution from Oil (1)
Crude (oil from ground) and refined petroleum (processed petroleum products) Highly disruptive pollutants Largest source of ocean oil pollution Urban and industrial runoff from land 1989: Exxon Valdez, oil tanker 2010: BP explosion in the Gulf of Mexico

Volatile organic hydrocarbons Kill many aquatic organisms Tar-like globs on the ocean’s surface Coat animals Destroy natural heat insulation, buoyancy Heavy oil components sink Affect the bottom dwellers

Faster recovery from crude oil than refined oil Marine life exposed to large amount of crude oil -> recover in warm waters with rapid currents in about 3 years Cold waters decades Refine oil another 10 to 20 years Cleanup procedures Floating booms Skimmer boats Large absorbent devices

Coastal Water Pollution
Solutions Coastal Water Pollution Prevention Cleanup Reduce input of toxic pollutants Improve oil-spill cleanup capabilities Separate sewage and storm water lines Use nanoparticles on sewage and oil spills to dissolve the oil or sewage (still under development) Ban dumping of wastes and sewage by ships in coastal waters Ban dumping of hazardous material Figure 20.17: There are a number of methods for preventing or cleaning up excessive pollution of coastal waters (Concept 20-4B). Questions: Which two of these solutions do you think are the most important? Why? Require secondary treatment of coastal sewage Strictly regulate coastal development, oil drilling, and oil shipping Use wetlands, solar-aquatic, or other methods to treat sewage Require double hulls for oil tankers Fig , p. 547

Deepwater Horizon Blowout in the Gulf of Mexico, April 20, 2010
Figure 20.18: On April 20, 2010 oil and natural gas escaping from an oil-well borehole ignited and caused an explosion on the British Petroleum (BP) Deepwater Horizon drilling platform in the Gulf of Mexico. The accident sank the rig and killed 11 of its crewmembers. The ruptured wellhead released massive amounts of crude oil that contaminated ecologically vital coastal marshes (Figure 8-8, p. 174), mangroves (Figure 8-10, p. 175), sea-grass beds (Figure 8-9, p. 174) and deep ocean aquatic life. It also disrupted the livelihoods of people depending on the gulf’s coastal fisheries and caused large economic losses for the gulf’s tourism business. This disaster was caused by a combination of equipment failure, human error, failure by BP to prepare for a major oil release, and inadequate government regulation of oil drilling in the Gulf of Mexico. Fig , p. 547

Case Study: The Exxon Valdez Oil Spill
1989: Alaska’s Prince William Sound 41 million liters of crude oil 5200 km of coastline Killed 250,000 seabirds $15 billion in damages to economy Exxon paid $3.8 billion in damages and clean-up costs Led to improvements in oil tanker safety and cleanup strategies Oil Pollution Act Banned single hull tankers – delayed until 2015

Reducing Surface Water Pollution from Nonpoint Sources
Agriculture Reduce erosion Reduce the amount of fertilizers Plant buffer zones of vegetation Use organic farming techniques Use pesticides prudently Control runoff Tougher pollution regulations for livestock operations Deal better with animal waste

Laws Can Help Reduce Water Pollution from Point Sources
1972: Clean Water Act : Water Quality Act EPA: experimenting with a discharge trading policy that uses market forces Cap and trade system Could this allow pollutants to build up?

Case Study: The U.S. Experience with Reducing Point-Source Pollution (1)
Numerous improvements in water quality due to the Clean Water Act Some lakes and streams are not safe for swimming or fishing Treated wastewater still produces algal blooms High levels of Hg, pesticides, and other toxic materials in fish

Case Study: The U.S. Experience with Reducing Point-Source Pollution (2)
Leakage of gasoline storage tanks into groundwater Many violations of federal laws and regulations Need to strengthen the Clean Water Act

Sewage Treatment Reduces Water Pollution (1)
Septic tank system Rural, suburban areas Wastewater or sewage treatment plants Primary sewage treatment Physical process Secondary sewage treatment Biological process with bacteria Tertiary or advance sewage treatment Special filtering processes Bleaching, chlorination

Sewage Treatment Reduces Water Pollution (2)
Many cities violate federal standards for sewage treatment plants Should there be separate pipes for sewage and storm runoff? Health risks of swimming in water with blended sewage wastes

Solutions: Septic Tank System
Figure 20.19: Solutions. Septic tank systems are often used for disposal of domestic sewage and wastewater in rural and suburban areas. Fig , p. 550

Solutions: Primary and Secondary Sewage Treatment
Figure 20.20: Solutions. Primary and secondary sewage treatment systems help to reduce water pollution. Question: What do you think should be done with the sludge produced by sewage treatment plants? Fig , p. 551

We Can Improve Conventional Sewage Treatment
Peter Montague: environmental scientist Remove toxic wastes before water goes to the municipal sewage treatment plants Reduce or eliminate use and waste of toxic chemicals Use composting toilet systems Wetland-based sewage treatment systems

Science Focus: Treating Sewage by Working with Nature
John Todd: biologist Natural water purification system Sewer water flows into a passive greenhouse Solar energy and natural processes remove and recycle nutrients Diversity of organisms used

Solutions: Ecological Wastewater Purification by a Living Machine, RI, U.S.
Figure 20.C: Solutions. This is an ecological wastewater purification system called a living machine. This Solar Sewage Treatment Plant is in the U.S. city of Providence, Rhode Island. Biologist John Todd is demonstrating this ecological process he invented for purifying wastewater by using the sun and a series of tanks containing living organisms. Todd and others are conducting research to perfect such solar–aquatic sewage treatment systems based on working with nature. Fig. 20-C, p. 553

There Are Sustainable Ways to Reduce and Prevent Water Pollution
Developed countries Bottom-up political pressure to pass laws Developing countries Little has been done to reduce water pollution China : ambitious plan By 2020, all cities with small sewage treatment plants that will make waste water clean enough to recycle back into urban water supplies

Solutions: Methods for Preventing and Reducing Water Pollution
Figure 20.21: There are a number of ways to prevent and reduce water pollution (Concept 20-5). Questions: Which two of these solutions do you think are the most important? Why? Fig , p. 553

What Can You Do? Reducing Water Pollution
Figure 20.22: Individuals matter. You can help reduce water pollution. Questions: Which three of these actions do you think are the most important? Why? Fig , p. 554

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