Coiform+Bacteria+Conclusion

By compiling the data from previous Watershed projects, we attempted to get a fuller set of data to work with so we could draw better conclusions than from just our data alone. However, the data we received from previous projects was spread out among months and even years. The large amount of time elapsed between the collection of data made it difficult to draw concrete conclusions. However, we inferred some things comparing coliform levels with temperature and pH levels. The months that had the highest coliform count were the months that also received the most rainfall. Rainfall is responsible for washing fecal matter from animals and overflowed sewerage into lakes and steams. Therefore, it makes sense that the months receiving the most rain (March-June) also had the highest coliform levels. After analyzing pH and //E.coli// level graphs from water samples from the quarry pond and after the dam, we concluded that pH does not have an effect on //E.coli//. In arriving at this conclusion we first decided that the sets of graphs from each site are relatively meaningless because they are based on only two sets of data. With this in mind we derived patterns from the graphs anyway. When we compared the results we got from the graphs from at the quarry to the ones from after the dam, we saw that they contradicted each other and therefore we were able to confidently conclude that pH does not affect coliform bacteria levels.Overall, our project was successful in that we were able to analyze a significant amount of data and use it to answer some our questions. Although we did not physically do as many tests as we had hoped, the data we accumulated was more than sufficient. In conclusion, our work with coliform bacteria, //E.coli// specifically, has made us both very proud of ourselves and each other.
 *  Conclusion  **

Experimental Error
In our project, there were many sources of uncertainty and experimental error. The biggest source of uncertainty was that we used a significant amount of information from previous projects. In doing so we were trusting that previous students' information was accurate. It is most likely that they made a few mistakes and had some "off" data. Since there was no way to asses the validity of their data, we trusted that it was good. In our own experiments we made several errors. When we were collecting our data, we didn't get a sample that was deep and far enough away from the bank. This would lead us to get a possibly inaccurate //E Coli// count, especially since we were getting water from areas that were more stagnant. The coliform bacteria could accumulate in these pools and reproduce, leading to higher levels of coliform than present in the entire body of water. In order to get an accurate coliform reading in a body of water, it would be best to take several samples on different points and depths of the water and then take the average. However, we did not do that so our results may reflect a higher or lower coliform count (though most likely higher due to the reasoning explained before). Also, the area that we took samples from the lake before the dam had a murky bank that had many leaves and other sort of decomposing material. It is possible that some E Coli was present on the leaves and the decaying matter, and our tests would reflect //both// the coliform present in the leaves and sediment and the coliform in the water. However, we were only looking for the //E coli.// present in the water. In addition, when we took the pH levels for the first time, we stuck the pH meter directly into the water instead of collecting the water first in a vessel and then performing the test. We also didn't swirl the water in order to get an accurate reading. By keeping the pH meter steady in a body of stagnant water, the meter reacts with the water surrounding it. It could have a higher or lower concentration of H3O+, so it is impossible to determine the direction of experimental error. The pH meter could also be calibrated incorrectly, leading to a false increase or decrease in the pH reading. Furthermore, we never tested the water samples right after we collected them. Usually, the samples would be left sitting in the fridge for a few days before we preformed tests. Not testing the water right away could have given the coliform bacteria time to die. In the event that they died, our tests would have shown that there was less //E.coli// in the water than there really was. When we finally did do the first test, the food we used was old. Since the food was old it may have not been very effective in growing the bacteria and therefore we would have counted less coliform bacteria than there really was in the water sample. Another experimental error we made occurred during the second test. During the second test, we unknowingly had the pump on reverse and it blew air out instead of sucking it in. In the end this did not matter because the second test results were inconclusive because we left the petri-dish in the incubator for too long. However, had we taken the petri-dish out on time, the pump being on reverse caused a lot of the water to spill out and so not all of the water sample was filtered. In the end this would have caused us to record less bacteria than there really would have been in the water. Further uncertainty lies in the possibility that we could have bad eyesight. This would have lead us to miscount the very small red dots. Counting more red dots than there really were would have led us to conclude that there was more //e.coli// than there actually was. Counting fewer red dots would have led us to conclude that there was less //e.coli// in the water than there actually was.

Further Research
Our topic is only the beginning of the study of water. We focused on two factors--the presence of coliform bacteria and pH--to determine the quality of water. While the conclusions we drew were by no means definitive, we could reduce our experimental error and gather more data in order to get better results. In addition, we could compare the data we got from Flat Rock Brook and compare it to other watersheds in the area. This would give us an idea of how clean McFadden's Pond is in comparison to other bodies of water in the area. Additionally, we could perform tests on the nearby Hudson and Hackensack rivers. Furthermore, we could do more studies on the affect of rainfall on coliform levels and temperature on coliform levels.

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