Chapter 21

Water Pollution

Core Case Study: Using Nature to Purify Sewage

  1. In John Todd’s living machine, describe the first stage of his ecological sewage treatment.
  1. Describe the second stage.
  1. Describe the third stage.
  1. List the 3 principles of sustainability that this sewage treatment system uses.

21-1 Water Pollution: Sources, Types, and Effects

  1. Give an example of a point source of pollution and a nonpoint source of pollution.
  1. List the 3 major sources of water pollution.
  1. Name 2 major problems associated with water pollution.
  1. Where does fecal coliform bacteria originate?
  1. What is the minimum amount of colonies of coliform that water can contain and still be safe for drinking? For swimming?
  1. What is the relationship between dissolved oxygen content and water quality?
  1. What role in water quality would an indicator species have? Give an example.

21-2 Pollution of Freshwater Streams

  1. What are the 2 ways that rivers and streams use to recover from excess wastes and heat?
  1. Where in a river would you find an oxygen sag?
  1. Why did the Cuyahoga River in Ohio catch on fire?
  1. Name 3 causes of fish kills and water contamination in developed countries.
  1. Why is stream pollution so prevalent in developing countries?
  1. List 3 reasons the Ganges River in India is highly polluted.

21-3 Pollution of Freshwater Lakes

  1. List the 2 reasons why dilution of pollutants is less effective in lakes.
  1. Name the 2 common nutrients that cause cultural eutrophication.
  1. Name 5 sources of these nutrients.
  1. Name 3 organisms that “bloom” from eutrophication.
  1. If these organisms are producers, why is this detrimental to a food chain?
  1. According to the EPA, about _____ of the 100,000 medium to large lakes and _____ of ther large lakes near major population centers in the United States have some degree of cultural eutrophication.
  1. Name one way to prevent and one way to clean up eutrophication.
  1. The 5 Great Lakes contain _____ % of the fresh surface water in the U.S. and _____ % of the world’s fresh surface water.
  1. Why are the Great Lakes so vulnerable to pollution?
  1. Why was Lake Erie impacted the most from the pollution?
  1. Name 3 organisms that have and may cause biological pollution in the Great Lakes [Case Study page 266].
  1. A survey by Wisconsin biologists found that _____ % of fish taken from the Great Lakes is unsafe for human consumption.
  1. What are 3 lessons that can be learned from the recovery of Lake Washington in Seattle?

21-4 Pollution of Groundwater

  1. Name 4 common pollutants that can seep into ground water.
  1. Why can’t groundwater cleanse itself like flowing surface water does?
  1. Why don’t we know as much about ground water pollution as we do about surface water pollution?
  1. What is the cheapest and most effective way to protect groundwater resources?

21-5 Ocean Pollution

  1. Why is it safer to dump sewage into the ocean rather than bury them on land?
  1. Which areas of the ocean bear the brunt of pollution?
  1. Name 3 ailments that a person can develop if they swim in water contaminated by sewage.
  1. What is produced as a result of red tide?
  1. List the progression of events that result from the introduction of large quantities of nitrates (NO3-) and phosphates (PO43-) into a coastal ocean area.
  1. The world’s third largest oxygen-depleted zone forms every spring and summer in ______off the mouth of the ______.
  1. List 6 preventative measures that can be taken to limit the oxygen depletion in this body of water.
  1. Name the largest estuary in the U.S.
  1. Name 2 point sources of pollution in this estuary that account for 60 % of the phosphates.
  1. Name 2 non-point sources that have contributed to 60% of the nitrates.
  1. What organisms were so abundant in this estuary that they filtered the entire volume of water every 3 days, and now it takes 1 year to filter the same amount of water by these organisms?
  1. Should an introduced species from Asia be the answer to cleaning up this bay?
  1. Where did the Exxon Valdez run aground causing an oil spill in 1989?
  1. The spill cost Exxon $ ______for damages, and the company earned $ ______over a 3-month span during that same year.
  1. What is the largest source of ocean oil pollution?
  1. Every _____ months, an amount of oil equal to that spilled by the Exxon Valdez tanker drains from the land into the ocean.
  1. How does oil pollution affect organisms on the surface of the ocean?
  1. How does oil pollution affect organisms on the bottom of the ocean?
  1. Which is easier for an organism to recover from, crude oil or refined oil?

21-6 Preventing and Reducing Surface Water Pollution

  1. Name the major source of nonpoint water pollution.
  1. List the 2 laws passed in 1972 and 1987 to control surface water point pollution.
  1. Describe the role of the 2 stages of a residential septic tank and drainage field.
  1. Describe the 3 stages of municipal sewage treatment plant.
  1. What is the purpose of chlorination after the third stage of water treatment?
  1. List the 3 uses or destinations of sewage sludge.
  1. Why can’t the sludge be used to fertilize crops for livestock?
  1. What is the benefit of a composting toilet?
  1. Describe the 3 stages of using wetlands to treat sewage in Arcata, California.
  1. Describe the role of a bioreactor.
  1. Name 2 groups of individuals that feel the Clean Water Act of 1972 is too restrictive.

21-7 Drinking Water Quality

  1. Where does New York City get 90% of its drinking water for its 9 million residents?
  1. Is this source cheaper than building a water purification facility?
  1. Is drinking bottled water the answer? Explain.

Critical Thinking

  1. What factors might limit the use of living machines (Case Study page 493) for purifying wastewater?
  1. When you flush, where does the wastewater go?
  1. What is the source of your drinking water?
  1. Should storm drains and sanitary sewers be combined or separate in your area? List the advantages and disadvantages of each option.