Fox River Water Study
The levels of nitrogen, phosphorus and pH in water were tested at the portion of the Fox River located in Waukesha, Wisconsin. I thought that nitrogen would be higher upstream than downstream, and that phosphorus and pH would be higher downstream than upstream. This was thought to be due to the surrounding commercial and residential areas that are near to the Fox River. I did not see any difference at the ten sites in phosphorus or pH. Nitrogen was the only nutrient to show any change as it increased from downstream to upstream.
Keywords: pH, nitrogen, phosphorus, water testing, Fox River
Rivers are an important part of the ecosystem. They provide habitat for aquatic creatures to live, and a water source for in agriculture crops. Rivers undergo change on a constant basis. Changes in how land is used, alterations in the natural habitat, and non-point source pollution are the most widespread and harmful threats to ecosystems, especially rivers (Hunsaker 1995).
The river is an excellent place to study how waterways can undergo change over time. Certain nutrients can be the cause of problems in rivers. Phosphorus can cause algae blooms and eutrophication in freshwater ecosystems. Nitrogen is very water-soluble and enters waterways via runoff, leaching, and from the atmosphere. Both of these can come from agriculture and land areas like lawns that use fertilizers (Greenhalgh 2001).
One of the main rivers that wind through southeastern Wisconsin is the Fox River. This river travels through many counties, including Waukesha. At many points along the river, you will find housing developments, industrial areas, and natural habitats including a bird and butterfly sanctuary. This experiment focused on the levels of nitrogen and phosphorus as well as the pH of the Fox River. My hypothesis was that nitrogen would be higher upstream than downstream due to the high potential for entering the river upstream near the industrial and commercial areas in the form of runoff. Phosphorus and pH would be higher downstream than upstream. I guessed this due to the fact that an industrial area is located upstream. There is also a car wash located far upstream. As the river flowed from north to south, the expected result was to see higher nitrogen and lower phosphorus and pH at the north end of the river and lower nitrogen and higher phosphorus and pH at the south end.
Materials and Methods
On October 13th, 2001, 10 sites were tested for levels of nitrogen, phosphorus, and pH in river water between the hours of 1000 and 1400. The 10 sites were located at 3 different locations (see figures 1 through 4) that spanned an approximate distance of 2.5 kilometers along the Fox River. I included aerial photographs of the 3 locations (figures 1-4) that show exactly where the samples were taken. The point of origin for collecting the samples was downstream, starting at the butterfly sanctuary (Figure 1). The last sample was taken at the furthest upstream point, which was at Frame Park, by the boat landing (Figure 4). Each site at the 3 locations was approximately 0.16 kilometers apart. A 50 ml sample was taken at each of the 10 sites with the LaMotts Limnological sampling and measuring outfit (Code 5861). Gloves and goggles were used to protect hands and eyes from contaminates in the water. Each sample was tested for levels of phosphorus, nitrogen and pH with the test kits according to the directions provided that were located in the La Motts Limnology test kit (Model AM-02, Code 5901-2). Results and observations were recorded. Data was analyzed, averaged, and correlated via an Excel spreadsheet.
Testing that was done at the 10 sites revealed no discernable
difference in the phosphorus levels or the pH values. The pH value did decrease at the second site (pH value of 7.25
compared to 7.5 at the other sites).
The phosphorus levels were 0.1 ppm and did not change as I traveled
upstream. The nitrogen levels were
highest downstream (0.4 ppm) and decreased as I traveled upstream (0.2 ppm). A
correlation was found when comparing nitrogen levels to site distance. This number, also known as the r-value was
–0.9. Table 1 shows the data obtained
from each site.
Each site was a specific distance from the next site. I planned this so that I was not testing one area that was right on top of the next. The distances between the first location and the last were about 2.5 kilometers. However, since the river twists and turns through the city of Waukesha, my choices of sites were limited for some were on private property. I included aerial photographs of the 3 locations (figures 1-4) that show exactly where the samples were taken. At Bethesda Park (figure 2), across from one of the sites (about 10 meters) was a drainage pipe from an apartment complex. Another thing to note is that the pH from site 2 was 7.25. This most likely was an error due improper cleaning of the test tubes. Seeing how I had some of my family members doing some of the tests (they volunteered), this too may be the cause of the different number. In looking at other river patterns to try and explain my results, I found that I am 3 times more likely to see elevated nitrogen levels than phosphorus levels (Smith et al 1987). This is probably due to agricultural runoff, fertilizer use on lawns, and other pollutants that find their way to the river. Phosphorus is a natural mineral. If I were to do further testing in the future along the Fox River, it would be interesting to see how the nitrogen levels are in the other counties. It would also be interesting to look at the source of the river, middle, and at the end to see if there is any drastic change the levels of the pH, phosphorus, nitrogen, or to evaluate peak flow (seeing how fast the water moves).
When applying the data in a correlation between the distance and nitrogen level, the r-value was –0.9. The r-value shows that the distance is inversely proportional to the nitrogen level. This shows that when the distance from site to site increased going upstream, the nitrogen level decreased.
Greenhalgh, S. and Faeth, P. 2001. Trading on water. Forum for Applied Research and Public Policy 16(1): 71-77.
Hunsaker C.T. and Levine D.A. 1995. Hierarchical approaches to the study of water quality in rivers. Bioscience 45(3): 193-203.
Smith, R., Alexander, R., Wolman, M. 1987. Water quality trends in US rivers. Science, 234(4795): 1607-1615.