18.1 and 18.2: Water Quality

Since the Clean Water Act of 1972, the quantities of nitrate and phosphate entering surface waters have

• decreased significantly for both point and nonpoint sources.

• have decreased for nonpoint sources but not point sources.

• have decreased for point sources but not nonpoint sources.

• essentially remained the same.

Tags

NGSS.HS-ESS3-4

NGSS.HS-LS2-6

The Clean Water Act has turned out to be ___________ in achieving its point source goals.

• very effective

• marginally effective

• ineffective

• a disaster

The central goal of the U.S. Clean Water Act was to

• make all surface waters swimmable and fishable.

• categorize water into types of use and then establish an array of different cleanup goals.

• end all water pollution in the U.S. by 2050.

• eliminate all nonpoint source pollution where economically feasible.

Tags

NGSS.HS-ESS3-4

NGSS.HS-LS2-7

The main reason that surface water pollution has largely decreased in the United States since 1950 is

• The Clean Water Act

• A series of epidemics that inspired action

• The discovery of newer technology that makes it cheaper not to pollute

• The decrease in water withdrawal for industrial uses

Tags

NGSS.HS-ETS1-3

In 1998, a change in the approach to water quality was initiated by _________ with an emphasis on _________.

• The EPA; cost-benefit analysis

• A series of epidemics that inspired action; watershed management

• Industry; cost-benefit analysis

• The EPA; watershed management

Tags

NGSS.HS-ESS2-5

Cultural eutrophication results from

• Natural sediment and nutrient levels

• A change in animal life as well as plants

• The disappearance of tributary streams

• Human activity

Tags

NGSS.HS-LS2-7

NGSS.HS-ESS3-1

An oxygen sag occurs most often

• In estuaries closest to a pollution source

• Immediately downstream from a pollution source

• Immediately upstream from a pollution source

• After the water recovers from the pollution source

Tags

NGSS.HS-LS2-3

Toxic metals such as lead, cadmium, and mercury

• Rarely threaten water supplies

• Can be toxic if high concentrations are reached

• Can be toxic in extremely small quantities

• Are the most common health threat in water

Which of the following are inorganic toxic substances sometimes found in local water supplies?

• Salts and lead

• Red tides

• Fecal coliform bacteria

• All of these are correct

Tags

NGSS.HS-ESS2-5

In order to avoid producing thermal plumes, power plants often

• Increase the efficiency of their energy use

• Warm entire rivers to ease temperature gradients

• Chemically alter their effluent

• Build cooling towers or ponds

Tags

NGSS.HS-ESS3-4

NGSS.HS-PS3-4