1. Branko Trocan & Andrew Wilkin D.O. & B.O.D.

2. Question- How does the D.O level in Rock Creek Compare to that of the lower Snake River?

4. Background Info. D.O test are important in the fact that they tell you the amount of D.O present in the water. To get a accurate results the test should be done when the water is at the same temperature as the body it was taken for and not a long time after it has been extracted.This is a important statistic to have because just like animals that live on the surface creature underwater need oxygen too. You many ask your self how oxygen get in the water and stays there.

5. Continued This is easy to find out with a little research. The are a variety of ways in which oxygen gets in the water. One is diffusion between the water and the oxygen at the surface of the water. Another is if a stream or river has a lot of rocks it breaks the water makes it go in the air it takes oxygen back with it. The plant that live under the water also release oxygen through photosynthesis.

6. Data Collection When comparing the dissolved oxygen in the lower Snake River with that of Rock Creek many conditions come into play. I found that the temperature plays a large role in the amount of dissolved oxygen in the water. Rock Creek’s D.O. is different to that of the Snake’s. There is less D.O. in the Snake. A couple of things could alter the D.O. level. The temperature of the water in the creek is lower than the Snake which can make a considerable difference.

7. More Information A common phenomenon with D.O is that its levels change daily or thought different times of the the levels well be different this is way you should take the test at the same time of day if you are performing test over a period of days. One reason that the level my change drastically is a algae boom. As a large amount of algae grows the D.O level increases. As the algae begin to die they are eaten by aerobic bacteria. As more and more of the algae dies the demand for oxygen becomes greater. An algae boom can decrees the D.O level so much that fish such as salmon could literally suffocate to deaf under water.

8. Data Analysis The B.O.D. or Biochemical Oxygen Demand in Rock Creek was also very good. In a healthy stream, like Rock Creek, oxygen gets replaced faster than it is used by organisms. In some streams bacteria decomposes a large amount of organic material.This in turn depletes the oxygen creating an un-healthy stream. The resulting decrease is known as the Biochemical Oxygen Demand.

9. Continued The B.O.D. level is the D.O. The water at Rock Creek had a very good concentration of dissolved oxygen. In the area we tested, the creek was fairly flat, and slow moving, but still had good D.O. Again, the cooler temperature is a major part of the percent of D.O. in the water but other factors come into view. When there are rocks or debris in the moving water a certain amount of oxygen gets cycled throughout it, therefore creating a greater percent of dissolved oxygen.

10. Rock Creek Rock Creek gets a good reading of oxygen due to the excessive plant life that gives off oxygen through its pores, rain water that traps oxygen as it hits the water, and the movement of water over the rocks which traps oxygen. The lower Snake is warmer and slower than the creek and therefore the river has less D.O. to support life. The creek has a very healthy D.O.level.

11. Excel Graph

12. Conclusion By comparing our test results with that of the test data base, we found that the lower Snake River has a lower D.O.%.Rock Creek is cooler and faster moving. Because of the colder temperature,speed,and the obstructions in the water,(rocks) more oxygen is dissolved into the water giving it a higher concentration of D.O.

13. Poems Dirty people all around There is a dirty person with his dirty hound. There is a smell that is not cool It smells a little like stool. Even though it didn’t snow, I sure enjoyed to go. Thank You Mrs. Dodds

14. Branko’s Poem When I went to rock creek the other day it was the first time I had ever been down there. I was surprised at how bad the conditions were. There was the distinctive smell of sulfur and sewage in the air. The foliage seemed not to be effected because their wasn't and shortage of shrubs or trees. There was still traces of the time that the location was an unofficial dump so in all it seems to be on the upswing and, someday even become a nice park again.

15. Works Cited Robyn L.Johnson, Scott Holman, Dan D. Holmquist. Water Quality with Computers. 6 Nov. 2001. www.S.I.T.E.comwww.S.I.T.E.com