Summary

Precipitation—a major control of fresh water availability—is unevenly distributed around the globe. More precipitation falls near the equator, and landmasses there are characterized by a tropical rainforest climate. Less precipitation tends to fall near 2030 north and south latitude, where the world’s largest deserts are located.

The water crisis refers to a global situation where people in many areas lack access to sufficient water or clean water or both. The current and future water crisis requires multiple approaches to extending our fresh water supply and moving towards sustainability. Some of the longstanding traditional approaches include dams and aqueducts.

Water pollution is the contamination of water by an excess amount of a substance that can cause harm to human beings and the ecosystem. The level of water pollution depends on the abundance of the pollutant, the ecological impact of the pollutant, and the use of the water. The most deadly form of water pollution, pathogenic microorganisms that cause waterborne diseases, kills almost 2 million people in underdeveloped countries every year.

Resolution of the global water pollution crisis requires multiple approaches to improve the quality of fresh water. The best strategy for addressing this problem is proper sewage treatment. Untreated sewage is not only a major cause of pathogenic diseases, but also a major source of other pollutants, including oxygen-demanding waste, plant nutrients, and toxic heavy metals.

Review Questions

1. Approximately 97% of all water on Earth is found in what reservoir?

A. Oceans

B. Lakes

C. Streams

D. Groundwater

E. Glaciers and ice caps

2. The majority of freshwater, whether accessible to humans or not, is contained in what reservoir?

A. Ocean

B. Lakes

C. Streams

D. Groundwater

E. Glaciers and ice caps

3. You are studying a river and notice that it contains chemical waste. You have thoroughly searched the entire length of the stream and ruled out that the waste is directly entering the stream. Instead, the waste must by entering by one of its many tributary streams. Because these streams empty into the river you are studying, they must be within the same…

A. Watershed

B. Irrigation district

C. Riparian area

D. Aqueduct

E. Water zone

4. Adding water to a recharge area would have what practical effect?

A. Increased amount of groundwater

B. A more pronounced cone of depression

C. Depletion of an aquifer

D. Less infiltration

E. Greater precipitation

5. With removal of groundwater, which of the following may result?

A. subsidence

B. sinkholes

C. cone of depression

D. decreased water table

E. All of the above.

6. For individuals living in areas where no freshwater is available, which one of the following would produce water that could be used for drinking?

A. desalination

B. groundwater mining

C. sublimation

D. transpiration

E. saltation

7. Three carcinogens are equally harmful at equal concentrations. In a terrible industrial accident, 2 tons of each type of carcinogen were discharged into a river at the same time. The residence times of each pollutant is as follows: Chemical X = 2.8 days; Chemical Y = 3.5 days; Chemical Z = 17.2 hours. Which one possesses the greatest risk of exposure to the nearby community over the course of a week following the spill?

A. Chemical X

B. Chemical Y

C. Chemical Z

D. All chemicals provided equal likelihood of exposure

8. Fertilizers applied to residential lawns and gardens can end up in water bodies through the process of surface run-off or movement through ground water. This type of pollution would be considered…

A.  Point source

B. Bioremediation

C. Non-point source

D. Throughput sourcing

E. Tangential

9. Which one of the following would most directly prevent a dead zone from forming in a water body that is already experiencing eutrophication?

A. Increase the O2 concentration in the water

B. Lower the nutrient levels

C. Increase the amount of algae and phytoplankton

D. Increase the amount of bacteria that decompose dead organic matter

E. Make the water more hypoxic

10. If you analyzed waste water directly after primary treatment, what would you notice?

A. Harmful bacteria and other biological agents have been killed or removed

B. The water is potable

C. Much of the dissolved solids have been removed

D. Many suspended solids have been removed

E. The water is mostly sludge

See Appendix for answers

Question Attributions

Theis, T. & Tomkin, J. (Eds.). (2015). Sustainability: A comprehensive foundation. Retrieved from http://cnx.org/contents/1741effd-9cda-4b2b-a91e-003e6f587263@43.5. Available under Creative Commons Attribution 4.0 International License. (CC BY 4.0). Modified from original.

Page Attribution

Essentials of Environmental Science by Kamala Doršner is licensed under CC BY 4.0. Modified from the original by Matthew R. Fisher and Joni Baumgarten.

“Review Questions” is licensed under CC BY 4.0 by Matthew R. Fisher.