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It is a hard truth to swallow, but nature does not care if we live or die.

It is a hard truth to swallow, but nature does not care if we live or die.

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It is a hard truth to swallow, but nature does not care if we live or die.

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  1. 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. Roger Rosenblatt

  2. Water Pollution (20) Water pollution: Any chemical, biological, or physical change in water quality that harms living organisms or makes water unsuitable for desired use. Water pollution causes illness and death in humans and other species and disrupts ecosystems. _____________________: Water pollution that can be traced to a specific spot (such as factory effluent or sewage treatment plant) because it is discharged into the environment through pipes, sewers or ditches. __________________________: Pollutants that enter bodies of water over large areas rather than being concentrated at a single point of entry. Ex. Agricultural fertilizer runoff, Livestock feedlots, and sediments from construction. The chief sources of water pollution are _________ _________________(Leading cause: Sediment from agriculture in the largest source. Other pollutants are fertilizers, pesticides, bacteria from livestock, and salt from irrigation), ________________(second leading cause from chemical release), and ________ (The third leading cause from erosion and toxic chemicals), but growth in population and resource use make it increasingly worse.

  3. Major Water Pollutants

  4. Human Disease From Polluted Water Infectious disease is one of the major water pollution problems people face. More than 500 bacteria, viruses and parasites have been identified in water supplies. _____________________________________ The WHO estimates that 3.2 million people (_______________________) die prematurely from infectious disease in their drinking water. ____________________________________________.

  5. Pollution of Freshwater Streams Flowing streams can recover from a moderate level of degradable water pollutants if they are not overloaded and their flows are not reduced. In a flowing stream, the breakdown of degradable wastes by bacteria _____________________ ______________________________________________.

  6. Dissolved Oxygen • Pollution reduces DO as decomposition of pollutants by bacteria occur and this reduces or eliminates populations of organisms with high oxygen requirements.

  7. Biochemical Oxygen Demand (BOD) Biochemical oxygen demand or B.O.D is the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample. _______________________________________. ______________________: DO is high BOD is low very low pollution = normal life. ____________________: Bacteria are using DO to break down pollutants. DO is decreasing BOD is increasing = pollution tolerant life. ________________: DO is too low (BOD very high) for fish to live as de-oxygenated water moves down stream. _________________: DO starts to rise as BOD decreases due to pollution decreasing = pollution tolerant life

  8. Stream Pollution in Developing Countries Most developed countries have sharply reduced ______________ pollution but toxic chemicals and pollution from ________________________________________. Stream pollution from discharges of untreated sewage and industrial wastes is a major problem in developing countries. Half of the world’s 500 rivers are polluted Water in many of central China's rivers are greenish black from uncontrolled pollution by thousands of factories. 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.

  9. World Rivers Cont. • 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. Daily, more than 1 million Hindus in India bathe, drink from, or carry out religious ceremonies in the highly polluted Ganges River. Trash Truck Disposing of Garbage into a River in Peru

  10. Successful Water Clean-up StoriesPollution Closer to Home The Cuyahoga is located in Northeast Ohio in the United States and feeds Lake Erie. The river is famous for being "the river that caught fire," helping to spur the environmental movement in the late 1960s. Native Americans called this winding water "Cuyahoga," which means "crooked river" in an Iroquoian language. The Cuyahoga River at one time was one of the most polluted rivers in the United States. The reach from Akron to Cleveland was devoid of fish. At least 13 fires have been reported on the Cuyahoga River, the first occurring in 1868 The 1969 Cuyahoga River fire helped spur an avalanche of water pollution control activities, resulting in the Clean Water Act, Great Lakes Water Quality Agreement, and the creation of the federal Environmental Protection Agency and the Ohio Environmental Protection Agency (OEPA). As a result, large point sources of pollution were closed. Water quality has recovered.

  11. POLLUTION OF FRESHWATER LAKES ___________________ in lakes is less effective than in most streams because most lake water is not mixed well and has little flow. • Lakes and reservoirs are often stratified and undergo little mixing. • Low flow makes them susceptible to runoff. Various human activities can overload lakes with plant nutrients, which decrease DO and kill some aquatic species.

  12. Eutrophication Eutrophication: (well nourished body of water) A natural nutrient enrichment of a shallow lake, estuary, or slow moving stream, mostly from runoff of plant nutrients such as phosphates and nitrates from the surrounding land. Oligotrophic: (Under nourished) A lake that is low in nutrients and will have very clear water. Low nutrients reduce organisms like algae that make the water murky. Cultural eutrophication: (water pollution) near urban areas, human activities increase nutrients above the natural nutrient enrichment. Nitrogen-phosphorus containing substances make their way to bodies of water from________________________________________________________________________________________________________________. Oligotrophic lake Cultural Eutrophication is considered pollution. Because this gets into our water supply from runoff, etc., and is something that is not normally in the water,

  13. Problems with Cultural Eutrophication During hot weather and drought, this nutrient overload produces dense growths or “blooms” of organisms. The water is cloudy and usually resembles pea soup because of the _______________________________ that are supported by the nutrients. These blooms reduce lake productivity and fish growth by _________________________________ that support fish. When the blooms die their decomposition by ________________________. This can kill fish and other aerobic animals. If nutrients continue to be added the water loses enough DO to allow ___________________________________. These organisms produce smelly gases like ___________ _________________________________________. • According to the EPA about 33% of medium lakes and 85% of large lakes near major population centers in the U.S. have some degree of cultural eutrophication.

  14. Lake Erie Since the 1960s scientists have recognized that Lake Erie was undergoing accelerated or cultural eutrophication. Eutrophication is a __________________________, but it can be accelerated by human activities. Concurrently during the 1960s, the public at large recognized that Lake Erie was highly eutrophic, as evidenced by: 1. Algal blooms covering large areas of the lake during summer months; 2. Attached green algae, called Cladophora covered most rocky and human-made structures; 3. Bulldozers removed decomposing algae, that were washing up on bathing beaches 4. Blue-green algae were causing taste and odor problems in some municipal water supplies; and dissolved oxygen was being depleted from many of the deeper areas of the lake.

  15. Preventing, Reducing and Fixing Cultural Eutrophication Prevention and reduction techniques: 1. Use expensive waste treatment to remove nitrates and phosphates before waste water enters lakes and oceans. 2. Banning or limiting phosphates in household detergents and cleaners. 3. Use soil conservation to reduce soil nutrient runoff. • Fixing Eutrophication (IPM) • Use herbicides and algaecides to kill plants • Deepen lakes to increase area for animals to live and increase oxygen content. • 3. Artificially oxygenating the water by pumping in fresh oxygen. • 4. Introducing competitors or insects that eat the plants. • 5. Mechanically remove excess weeds and plants. La Jolla, San Diego: Harmful algal bloom (HAB) events can be very bad for us. People who eat shellfish from waters experiencing toxic blooms can become very ill and can even die.

  16. A Legislative Mandate In December 2004, the Harmful Algal Bloom and Hypoxia Amendments Act of 2004 (Public Law 108-456) was signed into law. This Act, originally passed in 1998, to advance scientific understanding and detection, monitoring, assessment, and prediction of harmful algal blooms (HABs) and hypoxia (low oxygen). The Act calls for development of programs to research methods of prevention, control, and mitigation of HABs and establishes an interagency task force to follow progress on these issues. Harmful algal blooms are not just a problem along the coasts. The harmful algae seen here along the shores of Lake Erie in Ohio is called Microcystis. Microcystis blooms are increasing in frequency and duration in the Great Lakes.

  17. Sediment Pollution Sediment Pollution: Excessive amounts of suspended soil particles that eventually settle out and accumulate on the bottom of a body of water. Sediment pollution is caused by ________________ ______________________________________________________________________________________________________________________________ Sediment pollution _________________________ ______________________________________________________________________________________________________. Reduced light decrease photosynthetic phytoplankton's productivity that support fish populations. Human Health risks: Sediments adversely affect water quality by carrying toxic chemicals. Disease-causing agents can also be transported into water via sediments.

  18. Inorganic Compound Pollution Chemicals are contaminants that contain elements other than carbon. Examples include acids, salts, and heavy metals (mercury and lead). Many inorganic chemicals find their way into both surface water and groundwater from sources such as industries, mines, irrigation runoff, oil drilling and urban runoff from storm sewers. These compounds can __________________ _________________________________________________________________________. Human health risks: Lead and mercury are poisonous. Heavy metal exposure to developing fetuses in pregnant women has been linked to a variety of conditions such as mental retardations, cerebral palsy, cancer, developmental delays, causes kidney disorders and several damage the nervous and cardiovascular systems. Low levels of mercury in the brain cause neurological problems such as headache, depression, and quarrelsome behavior. In adults can lead to cancer.

  19. Thermal Pollution Thermal pollution: When heated water produced during certain industrial processes, ______________ ______________________________ is released into waterways. Thermal pollution causes decomposition of wastes to speed up, depleting the water of oxygen; this affects aquatic lifeby causing an _________________________________.. When a power plant first opens or shuts down for repair or other causes, fish and other organisms adapted to particular temperature range can be killed by the abrupt change in water temperature known as _______________. Elevated temperature typically decreases the level of dissolved oxygen of water. This can harm aquatic animals such as fish, amphibians and other aquatic organisms. Smaller developing organism (insect larvae) are the first to feel the effect. Thermal pollution may also increase the metabolicrate of aquatic animals, resulting in these organisms consuming more food in a shorter time than if their environment were not changed.

  20. Plastic Pollution Plastic pollution involves the accumulation of plastic products in the environment that adversely affects wildlife, wildlife habitat, or humans. The prominence of plastic pollution is correlated with plastics being ___________________, which lends to high levels of plastics used by humans. Plastic is found in the ocean as well as washed up on shore. Effects on animals: Plastic pollution has the potential to poison animals, which can then adversely affect human food supplies. Plastic pollution has been described as being highly detrimental to large marine mammals, described in the book Introduction to Marine Biology as posing the "single greatest threat" to them. Some marine species, such as sea turtles, have been found to contain large proportions of plastics in their stomach.When this occurs, the animal typically starves, because the plastic blocks the animal's digestive tract. Marine mammals sometimes become entangled in plastic products such as nets, which can harm or kill them.

  21. Plastic Cont. Over 260 species, including invertebrates, have been reported to have either ingested plastic or become entangled in the plastic. When a species gets entangled, its movement is seriously reduced, therefore making it very difficult to find food. Being entangled usually results in death or severe lacerations and ulcers. It has been estimated that over 400,000 marine mammals perish annually due to plastic pollution in oceans. In 2004, it was estimated that seagulls have an average of thirty pieces of plastic in their stomachs. The Great Pacific garbage patch, also described as the Pacific trash vortex, is circulating marine debris particles in the central North Pacific Ocean. The patch is characterized by exceptionally high concentrations of pelagic plastics, chemical sludge and other debris that have been trapped by the currents of the North Pacific Gyre.

  22. Estimates of size range from 700,000 square kilometers (270,000 sq mi) to more than 15,000,000 square kilometers (5,800,000 sq mi) (0.41% to 8.1% of the size of the Pacific Ocean), or, in some media reports, up to "twice the size of the continental United States".

  23. Plastic What Can We Do? ____________ ____________ ____________ ____________ ____________

  24. Groundwater Pollution Drinking water for about half of the U.S. and 95% in rural areas comes from groundwater. Chemicals used in agriculture, industry, transportation, and homes can spill and leak into groundwater and make it undrinkable. These include: ___________ ___________________________________ Once a pollutant enters groundwater it fills the aquifer’s porous layers of sand, gravel or bedrock like water saturates a sponge. This makes it difficult and costly to remove. The groundwater moves so slowly that it cannot cleanse itself of degradable wastes as quickly as flowing water. In addition groundwater _______________ _________________________________________________________________. Degradable wastes (DDT) can take decades to thousands of years to clean. Nondegradable wastes (lead and Arsenic) remain forever.

  25. Groundwater Pollution is a Serious Hidden Threat Few countries take the time to locate, track and test aquifers so not much is known about groundwater pollution. Leaks from a number of sources have contaminated groundwater in parts of the world. China gets 70% of the country’s drinking water from groundwater. 9 out of 10 aquifers in China are polluted or overexploited and may take hundreds of years to recover. • In the U.S. by 2003, the EPA had completed the cleanup of 297,000 of 436,000 underground tanks leaking gasoline, diesel fuel, home heating oil, or toxic solvents. According the EPA, one or more organic chemicals contaminate about 45% of municipal groundwater supplies. Arsenic in Groundwater - a Natural Threat Toxic Arsenic (As) can naturally occur at high levels in soil and rocks. Drilling into aquifers can release As into drinking water supplies. According to WHO, more than 112 million people are drinking water with As levels 5-100 times the 10 ppb standard. Long term exposure to As is likely to cause 100,000 premature deaths from skin, bladder and lung cancer worldwide.

  26. Leaking tank Aquifer Bedrock Water table 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

  27. Water Legislation About 54 countries mostly in North America and Europe, have standards for safe drinking water. The ____________________________ (SDWA) is the principal federal law in the United States intended to ensure safe drinking water for the public.The Environmental Protection Agency(EPA) is required to set standards for drinking water quality to determine the maximum contaminant level permissible that might adversely affect human health and oversee all states, localities, and water suppliers who implement these standards. This includes groundwater. Federal Water Pollution Control Act of 1972 which was renamed the Clean Water Act in 1977(CWA) is the primary federal law in the United States governing water pollution.Passed in 1972, the act established the goals of eliminating releases of high amounts of toxic substances into water and ensuring that surface waters would meet standards necessary for human sports (__________________________) and recreation by 1983. The Clean Water Act does not directly address groundwater contamination. __________________________ Even with all this legislation the United Nations estimates that 5.6 million Americans drink water that does not met the EPA safety standards. 1 in 5 Americans drink water from a treatment plant that violated one or more safety standard. SDWA applies to every public water system in the United States. There are currently more than 150,000 public water systemsproviding water to almost all Americans at some time in their lives.

  28. Is Bottled Water the Answer? Some bottled water is not as pure as tap water and costs much more. • 1.4 million tons of plastic bottles are thrown away. • __________are used to make plastic bottles. • The oil used to produce plastic bottles in the U.S. each year would fuel 100,000 cars.

  29. What Are the Major Water Pollution Problems Affecting Oceans? According to the 2006 State of the Marine Environment (UNEP), 80% of ocean pollution originates on land and includes oil and other toxic chemicals and solid wastes, which threaten aquatic species and other wildlife and disrupt marine ecosystems. As well as polluting the ocean itself land runoff pollutes coastal areas like wetlands, estuaries, coral reefs, and mangrove swamps. This is because 40% of the world’s people (53% in the U.S.) live on or near the coast. 80-90% of municipal sewage from developing countries is dumped into the oceans untreated. _____________________________________________________________________________________________________________________________________________________________________________________________________________ Saltwater covers about 71% of the earth’s surface There are 250,000 known species of marine plants and animals, many are food for other organisms and us.

  30. Coastal Areas _______________________________ _______. An estuary is a coastal body of water, partly surrounded by land, with access to the open ocean and a large supply of fresh water from a river. All river pollutants must pass through an estuary before entering the ocean. ______________________ _______________________________ Coral Reefs are built from layers of calcium carbonate, coral reefs are found in warm, shallow sea water. The living portions must grow in shallow waters where light hits. ____ ______________________________________________________________ The waters where coral reefs are found are often poor in nutrients. Yet, other factors are favorable such as temperature, sunlight year round, and zooxanthellae (symbiotic algae).

  31. A wetland is a land area that is ______________ ____________________________________, such that it takes on the characteristics of a distinct ecosystem.Primarily, the factor that distinguishes wetlands from other land forms or water bodies is the characteristic vegetation that is adapted to its unique soil conditions: Wetlands consist primarily of aquatic plants.__________________________ __________________________________________________________________________________________________________________________. Wetlands occur naturally on every continent except Antarctica.The largest wetlands in the world include the Amazon River basinand the West Siberian Plain. Mangrove swamps are coastal wetlands found in tropical and subtropical regions. They are characterized by halophytic (salt loving) trees, shrubs and other plants growing in brackish to saline tidal waters. ________________________ ________________________________________________________________________________________________________________________________________________________________

  32. Coastal Water Pollution Coastal waters have trouble cleaning themselves as compared to deep ocean because _________________________ _______________________ needed to decompose sewage, sludge and other pollutants. Recent studies of some U.S. costal waters have found vast colonies of viruses living in raw sewage. Human impact: Sore throat, eye irritation, respiratory disease, or gastrointestinal disease. Green tide caused by cyanobacteria Green tides are algal blooms of cyanobacteria. Algae tend to grow very quickly under high nutrient availability, but each alga is short-lived, and the result is a high concentration of dead organic matter which starts to decay. ________________________ _________________________________________________________ (misnamed a dead zone). Without sufficient dissolved oxygen in the water, animals and plants may die off in large numbers. Polluted runoff of storm water, sewage and agricultural waste introduce nitrate (NO3-) and phosphate (PO4-) which cause harmful algal blooms called red, brown or green toxic tides (eutrophication). Number one reason for coastal and beach pollution.

  33. Toxic Tides HAB (Harmful Algal bloom) is a common name for a phenomenon known as an algal bloom (large concentrations of aquatic microorganisms) when it is caused by a few species of phytoplankton and the bloom takes on a red or brown color. HAB’s are associated with the production of natural toxins, depletion of dissolved oxygen. The most conspicuous effects of these kinds of red tides are the associated wildlife mortalities of marine and coastal species of fish, birds, marine mammals, and other organisms. Red tides cause by Karenia brevis Red and brown tides is also potentially harmful to human health. Humans can become seriously ill from eating oysters and other shellfish contaminated with red tide toxin. Blooms can potentially cause eye and respiratory irritation (coughing, sneezing, tearing, and itching) to beachgoers, boaters and coastal residents. Brown tide cause by Aureococcus anophagefferens

  34. 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 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. 20-15, p. 548

  35. Natural capital degradation: a large __________________________(containing less than 2 ppm dissolved oxygen) forms each year during the spring and summer in the ________________as a result of oxygen-depleting algal blooms. Evidence indicates that it is created mostly by huge inputs of nitrate (NO3−) plant nutrients from farms, cities, factories, and sewage treatment plants in the vast _____________________. This problem was __________________________, which would have filtered out some of these plant nutrients.

  36. Ocean Oil: A Serious Problem Oil Spills: When a tanker accident happens, it gets lots of publicity. 1989, Exxon Valdez lost 10.8 million gallons of oil. But, more oil is released by normal operation of offshore wells, washing tankers & from pipeline or storage tank leaks. Although great human effort went into clean up measures, most of the _____ _______________________________. Crude petroleum (oil as it comes out of the ground) and refined petroleum (fuel oil, gasoline etc.) reach the ocean from a number of sources. 37-50% of the oil reaching the ocean is waste oil that is spilled, dumped or leaked onto the land or sewers by humans. (_____________________)

  37. Impacts of Oil _______________________________in oil immediately kill organisms, especially their larva forms. Oil spills have killed coral reefs. A recent study showed that diesel oil becomes more toxic to marine life with the passage of time. ________________coats the feathers of birds (especially diving birds) and the fur of marine animals, destroying the animals’ natural insulation and buoyancy. Many drown or die of exposure from loss of body heat. ___________sinks to the ocean floor and can enter estuaries and smother bottom dwelling organisms. (crabs, mussels, clams etc.) Recovery from crude oil exposure is about 3 years in turn exposure to refined oil takes 10-20 years.

  38. Oil Clean-up Oil is naturally broken down by marine bacteria over time; slower in cold waters. Fire can also burn off floating oil, but crude oil is hard to ignite. Chemical methods ___________________cause floating oil to clump together for easier pickup or sink to the bottom, where it usually does less harm. Dispersing agents break up oil slicks. However, these can also damage some types of organisms. Mechanical Methods _______________contain the oil spill or keep it from reaching sensitive areas _____________are used to vacuum up some of the oil into collection barges Absorbent pads or large feather-filled pillows are used to soak up oil on beaches or in waters that are too shallow for skimmer boats

  39. Scientists estimate that current cleanup methods can recover no more than 15% of oil from a major spill. Thus, preventing oil pollution is the most effective and in the long run, the least costly approach.

  40. The Key to Controlling Water Pollution Reducing water pollution requires preventing it, working with nature to treat sewage, cutting resource use and waste, reducing poverty, and slowing population growth. Reducing surface water pollution from nonpoint sources is the key to controlling water pollution. Ways to reduce non point water pollution: _______________________________________________________________________________________. 2. ____________________________________________ 3. ____________________________________________ 4. ____________________________________________ 5. ____________________________________________ 6. ____________________________________________ 7. ____________________________________________ 8. ____________________________________________

  41. Sewage Treatments Septic tanks and various levels of sewage treatment can reduce point-source water pollution. 3. Grease and oils rise to the top and solids fall to the bottom where _________________________. 4. The semi-treated waste water is sent to a drainage field to be filtered by stone and gravel and cleaned water is let back into the ground. 5. Every few years the tanks must be pumped out and is taken to the ________________________ ______________________________. How do they work? Used mainly in rural and suburban areas. Household sewage and wastewater is pumped into a settling tank.

  42. Sewage Treatment in Urban Areas In urban areas in the United States and most developed countries, most waterborne waste from homes, businesses, and storm runoff flow through a network of sewer pipes to wastewater or sewage treatment plants. Raw sewage reaching a municipal sewage treatment plant typically undergoes: • Primary sewage treatment: a physical process that uses screens and a grit tank to remove large floating objects (_______________________________________________) and allows settling. The solid material that settles out is called sludge. • Secondary sewage treatment: a biological process in which aerobic bacteria remove as much as 90% of dissolved and biodegradable, oxygen demanding organic wastes (including organic compounds like: ________________________________________). Oxygen may be added to assist the aerobic bacteria. This process is done in the ______________________. There biggest downfall is that sewage treatment plants are not equipped to remove ____________________________________________________

  43. Results or primary and secondary sewage treatment: 1. 95-97% of suspended solids and organic waste is removed. 2. 70% of toxic metal, phosphorus, and nonresistant synthetic organic compounds are removed. 3. It does not remove radioactive isotopes, persistent organic substances, and ______ _________________________. • Advanced or tertiary sewage treatment: • 1. Uses a physical process of micro-filters to remove specific pollutants _______________________________________. • 2. Disinfection: Water is ___________ to remove coloration and to kill disease-carrying bacteria( __________________ • ___________) and some viruses. UV and ozone are being looked at to replace chlorine, but they are expensive. • 3. Chemical treatments are used to ___________________ • __________________________components of waste. Reclaimed water can be reused in communities where water is scarce. Usually to water parks, landscaping and golf courses. Other water is released into rivers, lakes and the ocean. Sludge can be used as a soil conditioner but this can cause health problems if it contains infectious bacteria and toxic chemicals. Other sludge is set to landfills.

  44. Sewage treatment overview: 1. _________________________________________________________________________ 2. ____________________________________________________________________________ ____________________________________________________________________________ 3. __________________________________________________________________________ 4. __________________________________________________________________________ Other Solutions Natural and artificial wetlands and other ecological systems can be used to treat sewage. California created a 65 hectare wetland near Humboldt Bay that acts as a natural wastewater treatment plant for the town of 16,000 people. • The project cost less than half of the estimated price of a conventional treatment plant. The EPA estimates that 7.1 million people get sick each year from swimming in waters contaminated by sewage overflows and storm water runoff.

  45. ____________________________________________________________________________________________________________________________

  46. Water Properties 1. Dissolved Oxygen: The amount of oxygen gas dissolved in a given volume of water at a particular temperature and pressure. DO is necessary for fish and other organisms to go through cellular respiration. 2. Carbon Dioxide: Enters aquatic systems from the atmosphere and from respiration by animals. The concentration of CO2 varies at different depths because of light/photosynthesis. Necessary for plants to photosynthesize. 3. Nitrates: Contaminates shallow groundwater (100 feet or less) and usually comes from fertilizers. It’s a concern in rural areas where 80-90% of the residents use shallow groundwater for drinking. This harms humans because it reduces the blood’s ability to transport oxygen. 4. Sulfate: Problem because too much can kill fish. Gets in water from industrial processes and mining. 5. Iron: Causes problems because it separates out of the water and forms particulates (sediment), it tastes bad if it gets in our water, and can coat fish’s gills. Groundwater problems in wells, from natural minerals in rocks. 6. Phosphate: Plant nutrients that cause algae blooms. It comes from detergents, human wastes and fertilizers. 7. Coliform: General group of bacteria from animal wastes. It uses up available oxygen. Also causes e-coli disease. 8. Giardia: Organism (protozoa) that can cause diarrhea if you drink un-chlorinated water. It is a natural organism that lives in the guts of animals.

  47. 9. Chloride: Part of salts, but too many can cause too much salt in the water. Too much is bad; a little is okay. It is naturally found in water, but can come from pollution. 10. pH: Too high/too low can be bad; fish like 6.5-9.5; acid mine drainage can kill fish. 11. Hardness: Calcium and magnesium dissolved in the water. A little is good (50-400 ppm for fish is good), but very low or high is a problem. Low is more of a problem. Affects fish eggs, poor bone development. Can cause problems with cleaning clothes. Soap doesn’t bubble as much. Fix in homes by exchanging ions: Substitute sodium for calcium and magnesium. Water softeners usually do this. 12. Turbidity: Cloudiness/muddiness; blocks the light; coats fish gills. Water usage: Major Users – United States & global. Agricultural users are the biggest by volume, then industrial and municipal. Domestic water usage: On average all over the U.S. 58% of domestic water use is outdoors for gardening, swimming pools etc. and 42% is used indoors. Indoor use falls into the following categories: 31% Toilets 2% Baths 19% Showers 25% Clothes Washers 2% Dishwashers 18% Faucets