Exam 20: Water Pollution

To be considered safe for swimming, a 100 milliliter sample of water should contain ____ or fewer colonies of coliform bacteria.

Use the Figure above to answer the following question(s). -Choose the letter which indicates where bacteria are killed and water is ready to re-enter the environment.

In cultural eutrophication, fish die from

Agricultural activities are by far the leading cause of water pollution.

Each year, because of harmful algal blooms, 200 or more oxygen depleted zones form in coastal regions around the world.

The EPA has cleaned up 350,000 underground tanks in the United States that were leaking gasoline, diesel fuel, home heating oil, or toxic solvents.

The Exxon Valdez oil spill best illustrates point source water pollution.

Arsenic in the drinking water is not a concern in the United States.

About 45% of the largest water polluters in the U.S.have declared the Clean Water Act no longer applies to water they are polluting.

Use the Figure above to answer the following question(s). -Choose the letter that represents where the water is aerated.

More than seven million people in the United States get sick from swimming in waters contaminated by sewage overflows and storm-water runoff.

When Lake Washington became cloudy from the growth of blue-green algae, the culprit was discovered to be __________ from the area's sewage plants.

The breakdown of biodegradable wastes by bacteria depletes oxygen and may create an ____________________.

Use the Figure above to answer the following question(s). -Choose the letter that represents where activated sludge settles out in the biological process of sewage treatment.