Exam 20: Water Pollution

About ____ of U.S.lakes were tested unsafe for fishing,swimming,and other recreational uses.

Use the figure above to answer the following question(s). -In which zone are wastes being decomposed and low-oxygen fishes present?

The World Health Organization (WHO)estimates how many people on the earth do not have access to clean drinking water?

The primary cause of BP's Deepwater Horizon oil spill in the Gulf of Mexico was ____.

The Gulf of Mexico's "Dead Zone" is caused by high levels of ____ in the Mississippi River.

During this century,scientists expect to find many millions of ____ to become a major global health problem.

The majority of the oil pollution of the ocean comes from ____.

What percentage of expensive bottled water is actually bottled tap water?

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

Parking lots are a major source of point source pollution for rivers and lakes.

Agricultural runoff would be increased if farmers ____.

Which of the following is a point source of water pollution?

Developing countries dump the majority of their untreated sewage directly into freshwater ecosystems.

An important indicator of water quality is the level of ____________________,which changes due to the oxygen demand of breaking down biodegradable wastes.

The natural nutrient enrichment of a shallow lake,estuary,or slow moving stream is called ____.

Use the figure above to answer the following question(s). -In which zone has the stream begun to return a normal status following the oxygen sag?

Use the figure above to answer the following question(s). -In which zone are organisms that require oxygen most likely to be absent?

How do point and non-point sources differ? Give one example of each.

The biggest threat to water quality in the Great Lakes is from ____.

Storing drinking water in a reservoir is beneficial because it ____.