Most of Earth's liquid freshwater is found ________.

1. C) underground

2) Approximately ________% of Earth's total water is found in ice caps and glaciers.

1. A) 79

3) What percentage of Earth's total water is found in lakes?

1. E) 0.013%

4) Which of the following is TRUE?

1. D) Most of Earth's fresh water is frozen.

5) What percentage of Earth's fresh water is found in oceans?

1. D) 0%

6) What percentage of Earth's fresh water is found in rivers?

1. D) 0.001%

7) Only about 2.5% of all the water on our planet is fresh water, and

B) most of this is far from where humans live

8) Most of the precipitation that falls onto Earth's surface ________.

1. C) either runs off to form rivers or filters down into underground aquifers

9) One-fifth of Earth's total freshwater supply is in ________.

1. C) groundwater

10) An artesian aquifer occurs where ________.

C) a water-bearing layer is trapped between two layers that are less permeable

11) Humans use more fresh water for ________ than for any other purpose.

C) agricultural irrigation

12) Which of the following best describes a floodplain?

1. A) a region of land that is periodically flooded when a river overflows

13) Which of the following statements is TRUE regarding the future risks of decadal (11-year) and multi-decadal (35-year) droughts in the southwestern United States and Great Plains?.

1. E) Models indicate that both regions are more likely to experience decadal and multi-decadal droughts in the latter half of the 21st century than during the latter half of the 20th century.

14) Dam removal in the United States ________.

1. B) will probably continue because the environmental impacts of dams are reviewed periodically

15) Why was the irrigation of Soviet cotton farming operations a problem?

C) It drained the Aral Sea and increased the salt content of soils.

16) Sinkholes can result from ________.

1. A) overconsumption of water from aquifers

17) Which of the following will contribute to water conservation?

1. D) watering lawns at night, using low-flow faucets, and landscaping with native plants

18) Gray water can ________.

1. A) often be used for irrigation and watering lawns

19) Which of the following is one of the major pollutants of groundwater?

1. C) agricultural chemicals

20) The fish in the lake at the local park are dying, and a professor from the local college comes to investigate. First she measures the levels of dissolved oxygen because she wants to check for ________.

1. C) hypoxia

21) A watershed is ________.

1. A) the area of land that drains into a river or lake

22) "Blue-baby" syndrome is a consequence of excess ________ in the water supply.

B) nitrates

23) Levees are used ________.

C) to prevent flooding and facilitate shipping

24) A key characteristic of aquatic dead zones is ________.

1. D) a low concentration of oxygen

25) Why is grain production in the Great Plains considered largely unsustainable?

A) The Ogallala aquifer is being depleted for irrigation water.

26) A septic system is ________.

1. B) a rural method of processing wastewater

27) In a municipal wastewater treatment plant, the primary treatment step includes ________

1. D) letting sewage sit in large settling tanks so suspended solids can settle out

28) "Biosolids" produced at a wastewater treatment plant are often ________.

1. D) used as crop fertilizer

29) The resource allocation of the Colorado River's water is being complicated by ________.

1. A) the rapid growth of Las Vegas

30) A recent study has revealed that chlorinated solvents, gasoline, and radioactive compounds have become significant pollutants in ________ from ________.

A) groundwater; leaking storage tanks

31) Overpumping groundwater in coastal areas can cause ________ to move into aquifers, making the water undrinkable.

1. E) saltwater

32) Xeriscaping can save water by ________.

1. C) planting native or drought-resistant landscaping plants