Carol Lemcke

Laboratory Report on Water Quality

 

ABSTRACT

The purpose of this experiment was to compare the water quality of lakes or ponds within Milwaukee County to the water quality of lakes or ponds outside of Milwaukee. Due to the differences in the populations of people within these two areas it is hypothesized that the water will be of poorer quality within the city where greater populations exist compared to the water quality of the lakes and ponds just outside of Milwaukee where populations aren’t as great. The nutrients that were checked in each body of water were ammonia, nitrates, nitrites, and phosphates. Since all these nutrients are relevant to the pH of the water this was also checked along with the temperature. The materials I used for the experiment were a pH test kit, a nitrate N-phosphorus water test kit, an ammonia water test kit, a thermometer, and a metric tape measure. At about a meter from the edge of each lake or pond within Milwaukee County the following results were obtained: Scout Lake had a pH of 8 with the ammonia level at 0.025 ppm and nitrates at 0.88 ppm. Mud Lake had a pH of 9 with the ammonia level at 0.1 ppm and nitrates at .88 ppm. The Wilson Park pond had a pH of 8 with the ammonia at 0.1 ppm and nitrates at 2.64 ppm. The lakes or ponds outside of Milwaukee showed the following results a meter from the edge: Eagle Springs Lake had a pH of 8 with an ammonia level at 0.025 ppm and nitrates at .88 ppm. Waubassee Lake had a pH of 8 with an ammonia level at 0.025 ppm and nitrates at 0.88 ppm. Mukwanago County Park had a pH of 9 with an ammonia level of 0.1 ppm and nitrates at 2.64 ppm. All six of the areas tested had a temperature of 13 C with nitrite levels at 0.1 ppm, and phosphate levels at 0.2 ppm. Each variable was checked per the water test kit instructions. The temperature was obtained by the use of the thermometer. The results proved the hypothesis incorrect and that the water quality of lakes or ponds within Milwaukee County were comparible to those outside this area.

KEY WORDS

-Water Quality

-Water testing

-Water Nutrients

INTRODUCTION

In order for freshwater fish to thrive in their aquatic environment the quality of the water must fall between certain parameters. In areas with increased populations such as Milwaukee County, the chemical and biological quality of the lake or pond water could decrease greatly; especially if the public isn’t educated and monitoring isn’t conducted on a regular basis (EPA 1998). If the water quality in an area were depleted to the extreme it would not be able to support any aquatic animal life. This would have a severe effect on the ecosystem within the affected area.

The purpose of this experiment is to compare the water quality of three lakes or ponds within Milwaukee County where greater human populations exist to three lakes or ponds outside of Milwaukee where there are decreased populations. The quality of the water in these areas will verify whether or not it can support aquatic animal life. The nutrient levels that will be checked in each of the six areas are ammonia, nitrites, nitrates, and phosphates. These nutrients are all relevant to pH, which will also be checked along with temperature. Greater or decreased levels of the different nutrients along with varying temperatures can raise or lower the pH substantially.

In general, most freshwater fish thrive best in water with a pH between 6.7 – 7.2. The reason for this is the natural biological filter of that particular body of water. If pH levels fall below 6.5, which is more acidic, it can help deter bacteria, and render high nitrate and ammonia, but could also put a stop to the biological filter. The biological filter is the natural cycling of the nutrients within a body of water that keeps the ecosystem in balance for the survival of most aquatic life including many types of fish. Without a biological filter many species of fish would eventually die off. The same holds true if the pH gets up to 7.5, which is more alkaline. This would not only stop the biological filter from cycling, but also cause ammonia levels to be as much as ten times more toxic to the fish! Fish can only tolerate an ammonia level of 0.1 ppm or less. High phosphate levels can also drive the pH down with the same results. According to Henry N. Wooding (1998) ideal levels of nitrates for freshwater fish are 0.01 to 0.05 mg/l and phosphates at less than 3 mg/l. Nitrite levels need to stay below 0.33 mg/l.

 

METHODS

The data listed in this lab were collected out of Mud Lake, Scout Lake, The Wilson Park Pond, Eagle Springs Lake, Waubassee Lake, and The Mukwanago County Park Pond on October 9,1999. The first three sites were in Milwaukee County and the other three sites were just outside the county.

To perform the experiment I used the following materials: pH water test kit, nitrate N-phosphate water test kit, nitrite water test kit, ammonia water rest kit, a thermometer, a metric measuring tape, and clean containers with caps for water samples. When I went to each of the lakes and ponds I checked the water temperature with the thermometer a meter away from the edge. At this same measured distance I collected a water sample using a clean container, closed it tightly with a cap, and labeled what source it was from. I analyzed the pH and the ammonia on site per the test kit instructions for each. I then took the six collected water samples from each body of water back to the lab immediately and checked the nitrates, nitrites, and phosphate levels as listed in the water test kit instructions.

 

RESULTS

The results from the experiment show that the levels of the nutrients and the pH are all fairly consistent with one another and within safe levels for aquatic animal life with one exception ( Fig.1). There are two readings that were considerably high. The nitrate levels for the Mukwanago and Wilson Park Ponds were art 2.64 ppm. This level is considered high based on the parameters of .01 to .05 mg/l, which is considered safe for fish (1 ppm is approximately equal to 1 mg/l).

The averages taken for the lakes and ponds outside of the city as compared to the averages inside the city show all the nutrient levels to be consistent with one another except for the ammonia level which was slightly higher inside the city of Milwaukee on average. No other significant differences or high readings are shown from these results.

Water Quality of Lakes and Ponds

Ammonia (ppm)*

Nitrites (mg/l)

Nitrates (ppm)*

Phosphates (mg/l)

pH

Mud Lake

0.1

0.1

0.88

0.2

9

Scout Lake

0.025

0.1

0.88

0.2

8

Wilson Park Pond

0.1

0.1

2.64

0.2

8

Waubassee Lake

0.025

0.1

0.88

0.2

8

Eagle Springs Lake

0.025

0.1

0.88

0.2

8

Mukwonago Park Pond

0.1

0.1

2.64

0.2

9

*ppm=parts per million

AVERAGES COMPARED

Outside city

Inside city

Ammonia (ppm)

0.075

0.05

Nitrates (mg/l)

0.1

0.1

Nitrites (ppm)

1.47

1.47

Nitrites (ppm)

1.47

1.47

Phosphates (mg/l)

0.2

0.2

pH

8.3

8.3

 

DISCUSSION

The lakes and ponds that were tested in this experiment were places that were obviously open to the public or I would not have been able to perform these tests. According to the EPA (1998) water quality monitoring must be done on a regular basis for five major purposes. The first reason is to characterize waters and identify changes or trends in the quality over time so they know what to expect. The second reason is to be able to identify specific existing or emerging water quality problems so it doesn’t get out of control. The third purpose is for gathering information to design pollution prevention strategies and programs; the forth is to see that these strategies and programs are being inforced. The fifth and most important reason is to be able to respond to emergencies such as spills or floods. So I guessed that with this monitoring I shouldn’t come across a public lake or pond with poor water quality conditions. The EPA probably doesn’t allow any of the waters open to the public to become the least bit degraded because people can visit, fish, and swim in these areas. I would think that if it is safe for the public it should be acceptable for aquatic animal life.

The levels of the ammonia, nitrite, and phosphorus were all at acceptable levels for aquatic animal life according to Henry N. Wooding (1998) and S.K. Burley (1999). Wooding (1998) states that ideal readings for phosphates are less than 3 mg/l. Burley (1999) states that safe nitrite levels are less than 0.33 mg/l and safe ammonia levels are no more than 0.1 ppm.

The pH results I obtained didn’t seem to make a lot of sense when compared to the level of the ammonia in each sample. I would have expected the ammonia levels to be a little higher based on the pH and what is mentioned in Wooding’s (1998) article. He says that if the pH is high that will drive ammonia levels up. Something that could be a factor to this idea is the amount of waste in the water. Fish waste and any uneaten food will cause an increase in ammonia levels (Dorman 1998). This would be another factor to explore. The pH could still be high with ammonia levels low if the water is fairly clean from good water circulation by the means of inlets and outlets. These water outlets can carry away the different nutrients from within a body of water that get too high. Inlets help the circulation of the water in conjunction with the outlets and replenish the water supply while bringing in more species of plants and animals.

The only thing that didn’t make sense in this experiment was the two readings that are high for nitrates. The Mukwanago County Park Pond and The Wilson Park Pond both had nitrate levels of 2.64 ppm. This reading could have resulted from faulty analysis, a bad representation of a sample from the area, or the fact that these two places were small ponds that had no visible outlets.

 

LITERATURE SITED

 

Burley, S.K. 1998. PH and Hardness. Recommendations for Freshwater Fish. University of South Carolina. June 9,1998. <http://www.ucsc.edu/n lab/bio1.html>

P>Dorman, Dale. 1998. Testing for Water Quality. University of Georgia. College of Agriculture. September 12,1998. <http://www.ces.uga.edu/pubcd/c819-9w.html>

 

Wampler, J.E. 1999. Freshwater pH and Monitoring Quality. April 2,1999.

<http://biology.ucsc.edu/classes/bio2.html>

 

Wooding, Henry N. 1998. How to Interpret a Water Analysis Report. Pennsylvania State

University, College of Agriculture. August 21,1998. <http://www.ncinter.net/~lab/water.html>