The Effects of Rainfall on the Pollution and Mineral Content of the Western Duck Pond

Introduction
Pollution is a persistent problem in most bodies of water today. Having witnessed the murky state of the Western College Pond, we decided to investigate the state of the pollutants in its water. Rain plays a definitive role in pollution as it carries dust and other particles from the air to the ground as well as washing pollutants off vegetation, roadways, and buildings into the water system. The drought of the past summer has increased the build-up of substances on these surfaces. We hypothesize that when it does rain, the chemical-pollutant content of the pond will rise while the mineral concentration in the water will decrease.
The city of Oxford has a water treatment plant that removes the impurities of the water and makes it safe for human consumption. It removes iron and manganese, adds fluoride to prevent tooth decay, and chlorinates to kill bacteria. According to the EPA guidelines, the tap water should have the following qualities:
Substance MCL MCLG Highest Level Detected Min-Max Detected Contamination Sources
Fluoride 4ppm 4ppm 1.15ppm .87-1.15ppm Additive
Nitrate 10ppm 10ppm 3.68ppm 3.68ppm Agriculture, Geology
Total Trihalomethanes 100ppb 0 ppb 13 ppb 7-17 ppb Byproduct of chlorination
Copper AL=1300ppb 1300ppb 130ppb at AL nd -259 ppb Household Plumbing
Unregulated Contaminants for which EPA Requires Monitoring
Chloroform nr 0 2.9 ppb .9-2.9 ppb Byproduct of chlorination
Bromodichloromethane nr 0 5.3 ppb 5.3-2.0 ppb Byproduct of chlorination
Dibromodichloromethane nr 60 ppb 6.2 ppb 3.0-6.2 ppb Byproduct of chlorination
Bromoform nr 0 2.3 ppb 2.3-1.3 ppb Byproduct of chlorination
In the above, MCL is Maximum Contaminant Level, the highest level allowed in drinking water; MCLG is Maximum Contaminant Level Goal, the level in drinking water below which there is no known/expected risk to health; ppm is parts per million or milligrams per litre; ppb is parts per billion or micrograms per litre; nd is not detectable at testing limits; nr is not regulated; AL is Action Level the concentration of a contaminant which, if exceeded, triggers treatment or other requirements which a water system must follow.
Calcium and magnesium deposits cause water hardness, which is most obvious in appliances that heat drinking water and the small, white flakes released from thawing ice cubes.
The structure of the pond is not unique to water ecosystems. It is a small pond at the bottom of a hill that is fed by a small stream. This location makes it a prime target for gathering runoff pollutants and minerals. The stream also carries the water that comes off of Highway 27, which contains pollutants from the automobiles as well as from the atmosphere and ground.
What is unique about the pond is that there is a filtration device which pumps air through the water to prevent it from stratifying and turning over when the weather changes. This prevents some chemicals and minerals from building up at the bottom of the water, which would affect some studies of pond structure, but does not negatively influence our research because we are not comparing this pond to others. It also acts as a control on the project as the pump was operating before, during, and after the rainfall.
The ground structure of the Oxford area is important to the composition of the pond water, too. The area rock contains gypsum (Ca2SO4), limestone, Ca(CO3)2, dolomite, Mg(CO3)2, and iron sulfide (FeS). The iron sulfide reacts with the oxygen in the atmosphere and creates sulfate (SO4), which is one compound we will be testing for. These rocks act as a filter when water passes through them, helping to remove some substances, and the water, in turn, picks up the dust from the rocks and carries it away. Therefore, we should see evidence of all these compounds in our pond water samples.
Through this experiment, we hope to gather an understanding of the chemical composition of local rainwater in comparison to that of the Western Pond. This study should enable us to draw some definitive connections between the water pollutant levels and the precipitation. Such research is important to demonstrate the ramifications of a drought upon local water, which could lead to insights into farming methods when dealing with droughts as well as how this poses a threat to the future of area water. In testing the tap water, we hope to show how much safer it is to drink than ground water, as well as putting into perspective how the weather and human pollution effects the water ecosystem.

Relevance
Prior research has included "Effects of simulated acid rain and ozone on foliar chemistry of field grown Pinus ponderosa seedlings and mature trees." B. Momen and J.A. Helms, University of California-Berkley, 1994. This study researched the additive and interactive effects of simulated acid rain and elevated ozone on Carbon and Nitrogen contents of Pinus ponderosa foliage of various ages.
In previous Natural Systems courses, students have studied the effects of water on organisms, differences between moving and still water, and the quality of the drinking water at Miami University. No group, to our knowledge, has tested the effects of weather on the water quality, particularly concerning a drought. This makes our research unique to the program.
Could the pollutants in the pond be representative of a potential danger to people? By discovering the various chemicals that are in the pond water, we may demonstrate how closely people's actions are related to conditions of nature. Is the state of the water harmful to the organisms around it? What if the chemicals exist in our drinking water; are they harmful to us? Perhaps an understanding of the current water conditions would enable us to take steps to improve water quality. How does a shift in the pollution of the pond affect area wildlife, such as fish, plants, frogs, and birds that inhabit the area? Are there ways to ensure that our behavior combined with the weather doesn't drastically change their lifestyles or harm them in any way?

Materials and Methods

Materials:
distilled water jugs for storing samples
refrigerators for storing samples
three large basins to collect rain samples
water test kits for sulfate, Bromthymol Blue pH, nitrate, chloride, tannin and lignin,
hardness: total and calcium, phosphate, alkalinity
storm drain kit
pond water before rain
pond water after rain
tap water
distilled water
rain water
roof runoff water
tree runoff water

Sampling of the water took place in three stages. The first sample of pond water was taken immediately following the conception of this experiment in September 1999. This allowed us to get the chemical/mineral content of the Western Pond in the midst of the drought. At the first sign of precipitation, we set up basins to collect various samples of rainwater. One was set in the open field between Peabody Hall and Boyd Hall; the second was placed under a maple tree in that field to collect runoff from the leaves. The third basin was placed under a drain spout of McKee Hall to collect runoff from the roof of the building. Following the rain, we returned to the same spot of the Western Pond to collect a sample of the rain-altered water. These samples were stored in one-gallon distilled water jugs in dark refrigerators to preserve them for later testing. We used a sample of distilled water as the control for this experiment.
Unfortunately, two of our water samples (the rain from the open field and the runoff from the leaves) turned up missing before we were able to test them. Therefore, that data is missing from the experiment.
Each member of our group ran five tests on a sample of water. We worked in pairs, one sample of water per pair, to complete the necessary testing. Because we split up the testing, students were able to run the tests when their schedule permitted, with all the testing completed by November 23, 1999. The data was recorded on a data sheet we designed and then analyzed. The results were compared to each other, to the distilled water control, and to the EPA drinking water standards.
In order to ensure that the water tests produced unbiased results, we meticulously followed the instructions for each test. We also carefully washed and rinsed the test tubes and bottles with distilled water. To ensure that the class data was reliable, we had the students perform multiple tests. The results of these tests, however, cannot be analyzed statistically because a very limited number of tests were performed and the statistical tests would be of no use with only a small amount of data to process.

Results
Analysis of the water testing results shows that there is an immediate shift in the chemical composition of the Western Duck Pond following the rainfall. Many levels of pollution dropped, a couple increased, and a few numbers remained the same.
See the attached chart and graphs for further information.

Conclusions
Total and Calcium Hardness
This test analyzes the amount of mineral hardness in the water, which is the level of calcium, magnesium, and manganese present. The calcium hardness is the result of calcium carbonate present in the local bedrock. This accounts for the majority of the hardness in Oxford area water. The test showed that the calcium present increased from 8 to 10 grains/gallon, telling us that the water carried limestone dust into the pond water. The roof run-off had a low hardness. This shows that the rain would only have diluted the hardness present in the pond, which is proven by the drop in total hardness from 15 to 7 grains/gallon.
Sulfate
The Oxford bedrock contains iron sulfide (FeS), which reacts with the oxygen in the atmosphere and creates sulfate (SO4). This sulfate often combines with other metals to create more compounds, like calcium sulfate or sodium sulfate. The sulfate was highest in the pond water before the rain, while it was barely present in the roof run-off. This shows that the sulfate in the pond must be a build-up of dust from the iron sulfide rocks and is diluted by the rain.
Chloride
Chloride is necessary for healthy plant growth; therefore, it is present in many fertilizers. Our testing shows no change in the high range measurement in the pond before and after the rain. Thus, enough fertilizer must be washing into the pond to negate the effects of the increase in water. Because the high range chloride measurement of the run-off is 120 mg/L, twice the amount in the pond, much of the dust that settled on the roof of McKee must be from fertilizers. Chloride has been added to the distilled water, much like it is added to tap water, to help clean the water and ensure that people are receiving enough to keep themselves healthy.
Nitrate
Both the pond and McKee Hall are not situated in the immediate area of farms, so there is not much nitrate-rich fertilizer affecting the water. Thus, the readings for all samples of water are 0 mg/L of nitrate.

Alkalinity
The area bedrock contains limestone, Ca(CO3)2, which is a calcium carbonate compound. The alkalinity test specifically tests for calcium carbonate. Since the measurement for alkalinity increased after the rainfall, we conclude that the rainwater picked up dust off the limestone and filtered it into the water. This test is closely related to the calcium hardness test.
pH
pH refers to the negative base ten logarithm of the effective hydrogen ion concentration in gram equivalents per liter of water. The increase of acid water served to neutralize the pond, which was very basic due to the level of calcium carbonate in the water. The run-off from the roof shows that the area rain is fairly acidic; however, we are not positive if the pH was contaminated by the roof since we no longer have our pure rain sample.
Copper
Copper is present in the drinking water, but it is not present in any of our pond, rain, or distilled water samples. Therefore, the copper in the aforementioned drinking water must come solely from the pipes that carry the water into the buildings.
Phenols
Phenols are organic compounds that are byproducts of petroleum refining. They are present in very low levels in all of our samples. We can account for their presence in the pond as water running into it carries chemicals and dust off of Highway 27. Low levels cause color and taste problems in the water. High levels can kill aquatic life and humans, but the levels found in Oxford water are well within the safe limits.
Turbidity
Turbidity refers to the thickness/concentration of sediment suspended in the water. All our samples had low turbidity levels. This is expected of rain and distilled water. We were surprised that the pond, which looks very murky and grimy, had low turbidity. This may be due to the sample being from the surface, or that the turbidity in the entire pond is greater than any individual sample.
Phosphate
Phosphates are formed when some or all of the hydrogen of a phosphoric acid is replaced with metals. It is important to the metabolism of plants and animals. The roof run-off sample contained the highest level of phosphates of all our samples. We assume that this is because the phosphoric acid in the rain mixed with the metal on the roof and in the gutters, as well as the pollutant dust to produce phosphates. The increase in the pond water level is partially due to the phosphoric acid in the rain and the increase in phosphates that washed into the pond in the form of animal and plant waste.

Our hypothesis is that with the first rainfall following the drought, the chemical concentration in the pond will increase while the mineral concentration will decrease. We only had the ability to test for one chemical, phenols, and the level didn't change. Furthermore, the mineral levels did not behave in a uniform manner. The total hardness, sulfate, pH, and low range chloride all decrease, while the calcium hardness, alkalinity, and phosphate levels increased. The high range chloride, nitrate, copper, and turbidity levels did not change. The only conclusion that we can make about the effects of the rainfall is that rain after a drought causes a definite change in the composition of the pond water. If drastic enough, this shift could harm the plant and animal life in the Western Duck Pond. It is this rapid change that affects the animals and plants more than the pollutants that are present, because they cannot adapt to the new environment if it changes too suddenly.
This research is unique compared to the other projects we found in our research. The knowledge of these results can help people to preserve the local water environments. Questions that we have as a result of this research are:
1. Is the pollution in the run-off unique to the run-off or part of the rain itself?
2. How would the results differ if tested over a longer period of time? Over several droughts? Multiple rainfalls?
3. How would the results differ if there hadn't been drought conditions?
4. What would happen if we tested a different spot or multiple spots in the pond? Different depths?
5. How exactly do the animals (fish, ducks, etc) affect the water?
6. What would be different if the air pump was removed?

Further investigation on this subject could be improved if more areas of the pond
were tested, and the tests were done immediately after the sample was taken. More time for multiple runs of the tests themselves would probably yield more accurate results, as we were only able to run each test once on each sample of water. Statistical tests could then be used to analyze the data. It would also be nice to test the rain itself and the run-off from the tree in future investigations. If the supplies were available, we could run more tests to analyze the exact content of the water samples to find more accurate results. We could also test running water to compare to the sitting pond.
Weather plays a big role in the conditions of various environments. Pollution of the environment is easily tested in a water habitat. We have found that nature, as well as humans, greatly influence the drastic changes in water chemistry. Thus we should be wary of our treatment of the ecosystem during extreme weather conditions, such as a drought.

Water Testing Results

Test Pond Before Pond After Run-off Distilled Water
Total Hardness
Calcium Hardness
Sulfate
Chloride, High Range
Chloride, Low Range
Nitrate
Alkalinity
pH
Copper
Phenols
Turbidity
Phosphate

This is the data sheet that we used to collect the results of the water tests that the members of our group performed.

TIMELINE:

September 27, 1999: take first sample of the Western Pond water

September 27-28, 1999: first rainfall, we gather rain samples from open field, tree, and McKee roof

September 29, 1999: two water samples stolen

October 1999: prepare official proposal of project and student-generated lab

October 28, 1999: student-generated lab in Natural Systems seminar

November 12, 18, and 21, 1999: water tests run on samples

December 5, 1999: water tests run on distilled water

December 9, 1999: present results to class

December 16, 1999: final lab report due

Student Generated Lab: How does Oxford water compare to the Western Pond?

We divided the class into six small groups to teach them how to run a water test. Each group was assigned a sulfate test kit, a nitrate test kit, a total and calcium hardness test kit, or a tannin/lignin test kit. These tests were performed on two samples of tap water and two samples of pond water. This lab took place in class on Thursday, October 28, 1999.
Water Sample Type of Test Results
Tap Water 1 Sulfate 64 mg/L
Tap Water 1 Sulfate 50 mg/L
Pond Water1 Sulfate < 50 mg/L
Pond Water 1 Sulfate 50 mg/L
Tap Water 2 Nitrate 0
Tap Water 2 Nitrate 0
Pond Water 2 Nitrate 0
Pond Water 2 Nitrate 0
Tap Water 3 Total Hardness 22 grains/gal
Tap Water 3 Calcium Hardness 16 grains/gal
Pond Water 3 Total Hardness 14 grains/gal
Pond Water 3 Calcium Hardness 9 grains/gal
Tap Water 4 Sulfate 60 mg/L
Tap Water 4 Sulfate 65 mg/L
Pond Water 4 Sulfate < 50 mg/L
Pond Water 4 Sulfate 50 mg/L
Tap Water 5 Total Hardness 22 grains/gal
Tap Water 5 Calcium Hardness 13 grains/gal
Pond Water 5 Total Hardness 13 grains/gal
Pond Water 5 Calcium Hardness 9 grains/gal
Tap Water 6 Tannin/Lignin 0 mg/L
Pond Water 6 Tannin/Lignin 10 mg/L

We asked the class to contemplate the following questions related to their results:
1. Compare your results to the EPA water guidelines provided. Do your tap water results match the requirements? If not, is there reason to be concerned about the water quality in Boyd Hall?
2. What is the level of water hardness in Oxford? How do people compensate for this mineral hardness? For example, do they buy specific kinds of soap to produce lather?
3. How does the tap water compare to the pond water? Should the ducks be drinking it?
4. What can people do to help the pollution of the pond?

References

City of Oxford Water Quality Report 1999, Department of Natural Resources, Oxford,
Ohio.

http://www.epa.gov/305b/

http://www.scorecard.org

http://www.vcnet.com/koi_net/H2Oquality.html

Mason, B.J. "Acid Rain: its causes and effects on inland water." Oxford. New York:
Oxford University Press, 1992.

McCormick, John. "Acid pollution." Environment. Vol 40, No 3, pp 16-20+, Apr 1998.

Momen, B. and J.A. Helms. "Effects of simulated acid rain and ozone on foliar chemistry
of field grown Pinus ponderosa seedlings and mature trees." University of California-Berkley, 1994.

Nikiforuk, Andrew. "Acid rain's constant menace." World Press Review. Vol 44, No 9,
pp 38-39, Sep 1997.

Simonin, Howard. "The continuing saga of acid rain." New York State Conservationist.
Vol 52, No. 5, pp 54-55, Apr 1998.

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