One group tested water in a small stream behind the Knapp Center. This stream is surrounded by a forested area where we took samples. Just upstream the water flowed out of a culvert where water collected from the street, nearby playing fields, lawns, and the Drake Campus.The second group tested water in the small pond at Whitmer Park. In the area where the water was tested, there was a mud beach and a fair amount of vegetation growing in the water nearby. Whitmer Pond drains an are of mostly residential lands, and a large concrete settling pool was built last year to help deal with nutrient pollution.
The raw data as reported by groups. Ranges given are the range available in a test (i.e. the lowest to highest possible values as test results). OR stands for "over range":
| Test | Small Stream | Whitmer Pond | Comments |
|---|---|---|---|
| Free Chlorine (0.00-4.00 ppm) | 0.0 | 0.0 | |
| 0.0 | 0.0 | ||
| 0.04 | 0.17 | ||
| Low Phosphate (0.00 - 3.00) | 0.58 | 0.57 | |
| 1.6 | 0.64 | ||
| 0.51 | 0.66 | ||
| Dissolved O2 (0 - 12 mg/L) | 7.6 | 5.7 | |
| 7.5 | 9.8 | ||
| 7.4 | 5.2 | ||
| Ammonia (0 - 4 ppm) | 0.34 | 1.02 | |
| 0.11 | 1.99 | ||
| 3.96 | 0.76 | ||
| Nitrate (0 - 3 ppm) | 0.22 | 0.23 | |
| 1.34 | 0.15 | ||
| 0.73 | 0.20 | ||
| Nitrite (0 - 0.8 ppm) | 0.034 | 0.007 | |
| 0.056 | 0.0 | ||
| 0.017 | 0.058 | ||
| High Sulfate (6 - 100 ppm) | OR | 9 | |
| OR | 9 | ||
| OR | 9 | ||
| pH | 7.7 | 7.9 | |
| 7.6 | 7.7 | ||
| -- | 7.9 |
2) (2 pts) How many ppm of total nitrogen are there in the water?
3) (2 pts) Nitrates appear to be significantly lower in the lake water than in the stream water. Explain why this might be. (Hint: what does nitrate do in ecosystems?)
4) (2 pts) According to the LaMotte book, expected quantities of sulfate are between 3 and 30 ppm. Sulfate tends to be associated with various waste streams (municipal waste, pulp mills, steel mills, food processing). Where do you think the stream sulfate comes from? Should we be concerned about it?
5) (2 pt) In previous years, there has been a lot of chlorine in the stream water, but there wasn't this year. Why do you suppose that might be (To answer this, you need to think about the source water, and use that to figure out where the chlorine might have come from)?
6) (2 pts) According to the LaMotte book, phosphate levels of more than about 0.1 ppm are indicative of polluted water. Where might the high levels of phosphate come from?
7) (2 pts) Which water supply is more polluted? Where do you think the pollution comes from?
8) (5 pts) Comparing this data to data taken in 2004 and 2003, has water quality in the stream improved, gotten worse, or stayed about the same? Explain your answer, and if it is not a uniform change, explain what changes you think are the most important. You may need to do a little web research to answer this question.