Grade 9 | Tennessee
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Grade 9 | Tennessee
High on the steep slopes of Mount Collins in Great Smoky Mountains National Park, the West Prong of the Little Pigeon River begins. At its source the river is little more than a trickle, but by the time it reaches the city limits of Gatlinburg, it is a wide, flowing river that teems with life. The cool crystal water rushes past rocks and downed trees as the river’s path borders Highway 441, better known as “the Parkway.” One of my favorite childhood memories involves the time my family spent playing in the shallows of this river. As a toddler, I made leaf boats and launched them into the current to watch as they swiftly skirted away down the channel. I remember picking up white pebbles from the river’s bed with my toes as little fish playfully nibbled at my legs.
Today, however, ominous warning signs caution people that sections of the river are no longer safe for humans. As the river makes its journey through the cities of Gatlinburg, Pigeon Forge and Sevierville, its waters become contaminated. When I see those signs and smell the odor from the river, I sadly realize that the river’s journey—through commercial developments and residential areas, along highways and by storm drainage areas—allows it to collect substances that are potentially lethal to human beings. People can understand and avoid contact with the water, but how are these conditions affecting the fish, benthic organisms and macroinvertebrates that make the river their home? How does this contamination affect the river’s ability to sustain life? My concern for this issue led me to conduct a personal analysis of the water quality and biota in the West Prong of the Little Pigeon River.
Located in the southeastern United States, the West Prong of the Little Pigeon River forms the geographic and economic backbone of Sevier County, Tennessee. As a gateway community to the Great Smoky Mountains National Park, the area has experienced tremendous development since the National Park opened in 1934. Over 11 million visitors spend time each year in Sevier County, and the permanent population has also grown rapidly (Jones 1997). Construction to promote economic growth in the region has dramatically increased the impervious surface coverage in the area. Roofs, roads, driveways, sidewalks and parking lots concentrate and carry stormwater-borne pollutants into the river (Mallin et al. 2000). Numerous tourist attractions and resorts in Sevier County create high percentages of impervious areas and result in more runoff, or nonpoint source pollution. Road salt, grass clippings, copper residue from brake pads, petroleum products, pesticides, waste from leaking septic and sewer systems, and sediment are all examples of nonpoint source pollution. The U.S. Environmental Protection Agency’s “2010 Waterbody Report for the West Prong of the Little Pigeon River” listed the waterway as “impaired” for fish and aquatic life as well as for recreation.
Water quality monitoring is generally based on an assessment of the physical conditions of the water body, including temperature, sediment, flow and erosion potential. Evaluation of the chemical condition of the water includes levels of pH, nitrates, phosphates, dissolved oxygen and nutrients. Biological measurements that examine the abundance and variety of living creatures at a test site are also widely used to monitor water conditions (“An Introduction to Water Quality Monitoring” 2012).
Elevated water temperature is a problem in many streams. Deforestation of shorelines along rivers and streams allows sunlight to raise water temperature. When the water temperature is too high, many trout species suffer from declining success at spawning and even death. Most trout species require a water temperature between 12º-14ºC. Temperatures in the range of 23º-25ºC can be lethal. Water temperature also affects how much dissolved oxygen is in the water for the fish to breathe. The warmer the water, the less dissolved oxygen it can hold. Warmer water also speeds up the metabolism of the fish so they require more oxygen for biological functions (“The Environmental Importance of the Different Pollution Problems” 2011).
The alkalinity or acidity of water is measured by pH on a scale of 0, acidic, to 14, alkaline. Fish and other aquatic creatures require a range from 6.5 to 9.0. A pH of 7 is neutral. The solubility of nutrients and metal compounds is also affected by pH levels. High levels of nutrients can cause the excessive growth of aquatic plants. Decomposition of these plants can lower oxygen levels. Metal compounds are absorbed by aquatic animals more quickly at lower pH levels, resulting in the metals being more toxic to these creatures (“The Environmental Importance of the Different Pollution Problems,” 2011).
Fecal coliform lives in the intestinal tract of warm-blooded animals and aids in digestion. Although it is not a harmful bacterium, it is an indicator of the presence of dangerous bacteria, viruses, or parasites in water samples because it is abundant in human feces. Swimming in water with high levels of fecal coliform can make people sick if pathogens enter the body through the mouth, nose, ears or cuts in the skin. Typhoid fever, hepatitis, gastroenteritis, dysentery and ear infections can be contracted in water with high levels of fecal coliform. Fecal coliform can enter streams from illegal or leaky sewer connections, inadequate septic systems and poorly functioning wastewater treatment plants (Murphy 2007). Sewage overflows are a common problem in Sevier County when the area experiences flooding. Fecal coliform is also released from animal waste near farms, or by dogs, cats, bears, raccoons and other creatures. High levels of fecal coliform can cause problems for aquatic life by reducing oxygen levels and creating nutrient pollution, resulting in excessive plant growth (“How’s My Waterway?” 2012).
When I realized that the sparkling clear, healthy river that flows from the National Park is marked as unsafe for swimming, wading or fishing just a short distance away from the park boundary, I became very disturbed. If the river is toxic to people, surely the numbers of organisms that inhabit the water must be suffering or dying as well! So I decided to conduct an investigation to determine how water quality and the populations of biota are affected on the river’s path through the tourist cities of Gatlinburg, Pigeon Forge and Sevierville.
Materials and Methods
I determined that my first collection site would be just outside the National Park boundary above the Gatlinburg Water Plant. The second collection site was about two miles down the river, at North Gatlinburg Park, where the river leaves the city of Gatlinburg. The third location was about five miles down the river, where the waters leave the city of Pigeon Forge. The last site was at Sevierville City Park, about five miles farther down the river. I visited each site a total of twelve times over a four-month period. All four sites were visited on the same day, beginning at the Sevierville site and moving up the river to the National Park entrance. Using a water quality assessment datasheet that I designed, I recorded information about weather conditions, a description of the site and the water temperature. Samples of the water were collected for chemical tests that I conducted at home using a LaMotte Water Quality Test Kit. Using the materials provided in the kit, I checked the levels of pH, nitrates and phosphates. I also ran a test on each sample to check for fecal coliform in the water, and I tested to determine the dissolved oxygen level.
While at the site, I conducted an aquatic life inventory. This involved spending five minutes in the water at each site to check for organisms in the water or under rocks. Since I knew the waters were contaminated, I wore chest waders, long rubber gloves and goggles. I enlisted the help of family members to tally the numbers of specimens that I found. I used an identification key provided by the Save Our Streams organization. Numerous photos were also taken at each site. After I left each location, I cleaned up my equipment with a bleach solution, and I always showered as soon as I arrived home.
Data Analysis and Results
To prepare the data related to pH levels for a chart, I averaged all the levels for each site. The highest average pH level was found at the National Park boundary site, 7.70. Ironically, the lowest average pH level was found at the next nearest site, Gatlinburg, where the average pH dropped to 7.33, almost half a point lower. The pH levels rose as the river moved through Pigeon Forge and Sevierville. Those sites recorded average pH levels of 7.5 and 7.54, respectively. Levels may have improved at the sites farther down the river because of geography or dilution by tributaries flowing into the river.
When I calculated the average level of dissolved oxygen for each site, I found the cooler waters at the National Park boundary site had the highest level: 12.27 parts per million. The lower temperatures at that site allowed the water there to contain more oxygen. The dissolved oxygen levels dropped by only 0.14 ppm at the Gatlinburg site, to 12.13 ppm. A more substantial drop occurred at the Pigeon Forge site, where the average was 11.71 ppm. The Sevierville site registered the lowest average level, 11.67 ppm.
Initially, I was surprised to receive positive fecal coliform results on all four test sites. I expected that the National Park site would be negative. However, when I examined how much time each sample required to show positive results for the test, the National Park boundary site samples took much longer, an average of 33 hours, to show a positive result. This suggested to me that the concentration of fecal coliform in those samples was much weaker. The samples from the Gatlinburg site yielded the fastest positive results, in an average of only 5.25 hours. This implies that the Gatlinburg site had the strongest concentration of fecal coliform. The samples from the Pigeon Forge site showed positive results in an average of 9.33 hours, while Sevierville’s positive results were obvious in an average of 10.50 hours.
Normally I really enjoy wading and splashing in streams and rivers! When I had to complete the biological inventory for this study, though, I did not find the experience pleasurable for the Gatlinburg, Pigeon Forge and Sevierville sites. I calculated the Stream Index Value for each site by taking a five-minute inventory of all life forms in the water. I checked under rocks, in the water and along the shore for living creatures. I identified all the specimens and had a family member keep a tally of what was found on the data sheet. I added the totals and multiplied by three to arrive at a Stream Index Value for each visit to the four sites in the study. The National Park boundary site, as I expected, had the highest mean Stream Index Value, 245. The Gatlinburg site, however, averaged a Stream Index Value of only 19. On two visits to this site, I could not find a single creature! I think that these results may have been a result of the high levels of fecal coliform at the site. Nevertheless, I felt that this was a shocking drop in the numbers of biota, given the site’s proximity to the National Park. As the river continuedon its path, however, the mean Stream Index Values improved to 37 in Pigeon Forge and 125 in Sevierville, but were still only half as high as the count at the National Park boundary.
Many variables affect water quality, so accurate testing of the characteristics of any body of water is a challenging task. The water quality of the West Prong of the Little Pigeon River is affected by recreation, tourism, sewage discharge, stormwater runoff, small industries, traffic, air pollution and agriculture. Additionally, weather patterns, precipitation and the number of tourists visiting the area, along with a wealth of other, unknown variables, may have affected my results. The high pH levels, high dissolved-oxygen levels and the longer amount of time required to cultivate a positive result in the fecal coliform tests and Stream Index Values in the samples from the National Park boundary site indicate that water quality and the numbers of biota decline dramatically as the West Prong of the Little Pigeon River moves through more populated areas. My hypothesis was confirmed.
Even though the presence of warning signs along the West Prong of the Little Pigeon River disturbed me greatly, after I completed my study I came to feel that the signs were a positive indication that the public is being made aware of the river’s problems. Sadly, the general population may not be bothered about the reduced numbers of macroinvertebrates in the river, but signs that warn of danger to people attract attention! Ironically, the contaminated areas of the river pass through city parks designed for public use. The smell of urine in the water on some days was almost unbearable on some of my visits to those areas, and even though the waters at North Gatlinburg Park are stocked each Thursday, I never saw a single fish in all my visits to the site. With so little natural food available, the fish must swim away or die. The West Prong of the Little Pigeon River is a tremendous economic and natural resource for Sevier County, and this study reveals that its delicate ecosystem is in danger.
“2010 Waterbody Report for West Prong Little Pigeon River.” Watershed Assessment, Tracking and Environmental Results. U.S. Environmental Protection Agency (2010). Retrieved from the World Wide Web. http://iaspub.epa.gov/tmdl_waters10/attains_waterbody.control
“An Introduction to Water Quality Monitoring.” U.S. Environmental Protection Agency (2 Oct. 2012). Retrieved from the World Wide Web. http://water.epa.gov/type/watersheds/monitoring/monintr.cfm
“How’s My Waterway?” U.S. Environmental Protection Agency. Retrieved from the World Wide Web on 15 Jan 2013. www.epa.gov/mywaterway
Jones, Robbie. The Historic Architecture of Sevier County, Tennessee. Tennessee: Smoky Mountain Historical Society, 1997.
Mallin, Michael, Kathleen Williams, Carthur Esham, and Patrick Lowe. “Effect of Human Development on Bacteriological Water Quality in Coastal Watersheds.” Ecological Applications10.4 (August 2000): 1047-1056. Retrieved from the World Wide Web. http://www.esajournals.org/doi/abs/10.1890/1051-0761(2000)
Murphy, Sheila. “General Information on Fecal Coliform.” Boulder Area Sustainability Information Network (BASIN), 2007. Retrieved from the World Wide Web. http://bcn.boulder.co.us/basin/data/NEW/info/FColi.html
“The Environmental Importance of the Different Pollution Problems.” Water Quality. Washington State Department of Ecology, 2011. Retrieved from the World Wide Web on 9 Feb 2012. http://www.ecy.wa.gov/programs/wq/tmdl/palouse/impairments.html
This winning entry in the Museum's Young Naturalist Awards 2013 is from a ninth grader. For the last several years Sterling has been investigating the health of streams in and around his hometown of Sevierville, Tennessee. His current investigation involved monitoring the health of a pristine mountain stream as flowed from its origins in the Great Smokey Mountains National Park through the cities of Gatlingburg, Pigeon Forge, and Sevierville. His essay presents:
Have students explore the process of science with a discussion based on this essay.
1. Tell students that in the essay they are about to read a student’s concern for the health of a river led him to conduct water testing along the river’s route. As students read the essay, have them focus on how the data were recorded and presented.
2. When students have finished have them identify how the student recorded and presented the data. Ask:
3. Allow students time to discuss other aspects of the essay they found interesting.