Sometime in your life, someone (probably your mother) told you not to eat yellow snow. If you have ever hiked in Utah’s mountains, you should have been warned not drink out of the streams unless the water has been filtered, boiled, or treated in some way. If you have traveled out of our country, you were probably advised to drink only bottled water. So, why all these warnings about water? Because many, maybe even most, of our water sources are polluted in some way or another. In this assignment you are going to examine and analyze data about water pollution.



1. How do scientists measure the quality of our waters?

2. Give two reasons why scientists measure water’s temperature.

3. What is D.O.?

4. Why is D.O. important in measuring water quality?

5. What affects the D.O. of a stream?

6. What is the pH range of “healthy” water?

7. Why is the pH of a stream important?

8. Identify four things that can happen if there are too many nutrients in the water.

9. Identify three toxic substances that scientists test for.

10. What is turbidity?

11. Why do scientists test water’s turbidity?

12. Why are scientists concerned about the presence of fecal coli forms in a stream or lake?

13. How does a visual survey help a scientist determine water quality?

14. What is biological sampling?

15. How does biological sampling help a scientist to determine water quality?

  • Click on “Three Big Pollutants”
16. Write a paragraph describing each of the three big pollutants. Explain why each is a pollution problem.

  • Click on “Where Are These Pollutants Coming From?”
17. Where are the majority of our pollutants coming from?

18. How does pavement increase water pollution problems?

19. How do straightened streams and cement lined canals increase water pollution problems?

PART TWO: The first part of this assignment was a simple “read-and-write” exercise. The answers to the questions were all found in the reading material. The next part of this assignment requires you to think and analyze. Use the information you learned above to answer the following questions. Be sure to use COMPLETE SENTENCES to answer the questions.

1. Water released from a dam comes from the bottom of the reservoir, which means that it is VERY cold. Why would colder-than-normal water be considered a water pollution problem?

2. To build a housing development, engineers changed the path of a local stream. As a result the stream flowed more slowly than usual so the sun had more time to warm the stream waters. As a consequence the water temperature in the stream increased ten degrees Celsius. Why would warm water be considered a water pollution problem?

3. You test the D.O. in a local stream and find that it is much lower than normal. What conclusions can you draw from this data?

4. You test the pH of a local stream and find that it is 5.5. What does this data tell you?

5. You want your lawn to be extra green for an upcoming party so you double the recommended amount of fertilizer you apply to your lawn. What water pollution problem could occur as a result of your action? [Fertilizer is a plant nutrient. Think what would happen to local streams, rivers, and lakes if extra plant nutrients were added.]

6. Lead is found in your water supply. Why is this a problem?

7. A lake you love to visit is usually very clear. Road construction upstream has caused the lake to be very turbid. Give two reasons why this is a water pollution problem.

8. Cattle are grazed on the mountain side. Give two reasons why this might be a water pollution problem for the streams in the area.

9. You love to fish and have found that, by turning over rocks in the streams where you fish, you can find “rock rollers” (little worm-like insect larvae) that work well as bait. This year, when you go to fish, you find that, where there once were hundreds of “rock rollers”, now there are very few. Why does this indicate a water pollution problem?

10. How are water temperature and D.O. related?

Good job! Send me the answers to ALL these questions, both parts one and two. If you have read and thought well and have used complete sentences to answer the questions, you will receive a good grade.


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