Tennessee: River of Plastic

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Andreas has been swimming with only occasional breaks for three hours. I try my best to guide him by keeping my kayak just ahead and to the left in his field of view. With each alternate breath he sees my boat. Between breaths he can just see his fingertips in the pea-green water of the Tennessee River as they execute another freestyle stroke. Except for a woman off to our left, we have separated ourselves from the pack of about one hundred swimmers taking part in this ten mile race. My job is easier. I have time to admire the ranks of trees blanketing the steep slopes to either side of us, the Turkey Vultures scribing circles in the sky high above, and the illuminated sandstone cliffs that form the upper cap of the Cumberland Plateau hundreds of feet above us.

I also have time to think about our swim of the entire 652-mile length of the river last year and the immense amount of water quality data we accumulated then. As it turns out the Tennessee is a fairly clean river. Its levels of pharmaceuticals are lower than what is found in the Rhine River. The heavy metals are low. The nitrates and phosphates are acceptable for a river flanked by extensive fertilizer-dependent agricultural areas. There was one big surprise, however – microplastics. These are pieces of plastic less than 5 mm in diameter that are either the broken down bits of larger plastic or small manufactured beads that are used in some toothpastes and soaps for their abrasive qualities. We analyzed for plastics by pumping 1000 liters of water (same as one cubic meter) through a filter that caught particles in the range of 0.025 mm to 0.5 mm. When we analyzed the first river sample we were so startled by the results that we analyzed it again. What we found was a staggering number: over 17,000 particles per cubic meter. This is the highest concentration of plastic particles ever detected in any river. Looking at the exact same size range a few years earlier in Europe’s Rhine River, Andreas only found 200 particles per cubic meter. The Rhine has ten times as many people living in its watershed compared to the Tennessee. How is this possible?

An answer may lie with another analysis we conducted that looked at the type of plastic found in our samples. Below is a diagram that shows the exact number of each plastic type found in Pickwick Lake, one of the nine reservoirs along the river:

GSA Microplastics

Types of plastic particles found in a representative sample from Pickwick Lake. PE=polyethylene, PP=polypropylene, PA=polyamide.

This chart shows that almost half of the plastic found was polyethylene. Most polyethylene is used in light weight packaging and plastic grocery bags. The plastic wrap around produce and the plastic bag it is put into at the checkout counter are likely of this plastic. But how did all this polyethylene get into the river? Although we don’t know for certain, it is highly likely that the majority of it is derived from litter. The samples taken along the length of the Tennessee show roughly the same number of plastic particles from Knoxville, TN to Paducah, KY. Thus we are not dealing only with inputs from particular cities or industrial zones. We as a society are responsible for this plastic load in the river.

Why are microplastics in our waterways an issue? After all, plastic can be swallowed without negative side-effects by animals and people, right? This would be largely true if organisms consumed clean plastic. But plastic particles in a river have been exposed to a host of man-made chemicals that like to stick to their surfaces. Chemicals that include pharmaceuticals, PCBs and heavy metals. In addition to sampling for microplastics during the Tenneswim we also sampled for hundreds of man-made chemicals and heavy metals. What we found was a cocktail of chemicals like anti-seizure medications, blood pressure medications, over a dozen pesticides, pain killers, artificial sweeteners, contrast agents for x-ray and MRI procedures, caffeine, sunscreen ingredients, perfluorinated compounds (PFCs), and a host of other chemicals. That means that each plastic particle acts as a potential transport agent for some of these chemicals. We know that this has caused serious disruption of physiological processes in some river invertebrates (e.g., endocrine disruption), but we don’t yet know about the effects on fish – or humans that drink river water.


The American Paddlefish is a Tennessee River inhabitant that feeds on zooplankton. It is not known what impacts (if any) microplastics have on its physiology.

As I watch Andreas swim I realize that this means he is carving his way through thousands of plastic particles every few seconds. This also means that the Tennessee River is dumping 32 million plastic particles into the Ohio River every second.

As we emerge from a bend in the river I can see the big, orange buoy that marks the finish line off in the distance. Another 20 minutes and we reach it, Andreas coming in third out of a field of over 100 participants. We leave the water, but the microplastics continue on their journey to the Ohio, then the Mississippi, and ultimately the Gulf of Mexico. There they add to the 9 million tons of plastic entering the oceans annually. Estimates are that if things continue unabated, there will be more plastic particles in the ocean than fish by 2050.

Of Mining and Rafting on the Ocoee River

The Hiwassee River is one of the largest tributaries feeding the Tennessee River. It has its origins to the east, high in the mountains of the Blue Ridge. As it spills out of the mountains it is joined by the equally large Ocoee River, but maintains the name Hiwassee. Both the Ocoee and Hiwassee have cut deep, scenic gorges into the ancient rocks of the Blue Ridge. This is the state’s premier whitewater rafting area. The Ocoee has a deep, troubled environmental history that began in the 19th Century. This history is largely unknown to the tens of thousands of tourists that enjoy the river’s whitewater and scenic beauty and the easy access afforded by highway 64, which runs like a ribbon alongside the river. High on the Ocoee’s watershed is the bowl-shaped valley called the Copper Basin, where copper and other metals were discovered in the 1840’s. Soon the region became the largest copper mining district in the eastern United States. The copper occurred in ore, meaning the metal was disseminated through the rocks and difficult to extract. The process of getting the copper out of the ore was done on site, using large volumes of firewood harvested from the local forests to roast the ore. Aside from denuding the local forests, this roasting process had a more sinister side effect. The ore also contained large amounts of elemental sulphur which, when released into the air during the roasting process, formed sulphuric acid in the sky above the Copper Basin. Rains brought this acid down as a caustic mist over the basin and lead to the annihilation of all existing vegetation. Soon the Copper Basin became a moonscape, made famous by several photographs like one below.


Denuded landscape of the Copper Basin.

The soil became sterile and, lacking any vegetative cover, succumbed to massive erosion. Local streams transported the sediment load to the Ocoee, which by 1912 had already been dammed in several locations. These dams pre-dated the Tennessee Valley Authority and provided electricity to eastern portions of the state. One dam location was chosen at the entrance to the Ocoee River gorge, a narrow spot where the river exits the Blue Ridge between two high knobs of rock. This dam forms the extensive Parksville Lake. Sediment from the denuded lands upstream soon became trapped behind the dam, replacing much of the water with solid grains of weathered rock and soil. If the lake level drops just a foot or two today, the lake waters in the upper reaches suddenly disappear and a vast mudflat appears. In these areas Cypress trees have been planted and are a testament to the shallow nature of the lake. It wasn’t until the 1970’s that suitable pines became available to revegetate the Copper Basin. Now the basin is green and lush again, with place names like “Bura-Bura” and “Copper Hill”, the occasional mine tailings pile, and the lake sediment the only visible evidence of these former times.

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View of Parksville Lake from Chilhowee Mountain. The lake is formed by a dam (Ocoee #1) between the two knobs at right margin of photo.

The booming whitewater industry is relatively new, having begun in the mid-1970’s when the damaged flume which carries water to one of the power stations was closed for repairs. This meant that water that was usually carried from the river and caused the Ocoee to be in an almost constant state of dryness found itself flowing free again in the river bed. Boaters quickly discovered the possibilities and after much back and forth with TVA, commercial boating on the river became a big-business, permanent fixture. In 1996 the Ocoee River was chosen as the site for Atlanta’s Olympic whitewater events. A portion of the river bed was completely re-engineered to produce the proper rapids needed for an Olympic event. The Olympic whitewater center remains a major tourist attraction for swimmers at low water and boaters at high water.


Watching the action at the Olympic Whitewater section on the Ocoee.

652 – Mile Swim for Science on the Tennessee River is Completed and a New World Record is Set

21082858_208148266387201_1811594108559940295_oOn August 29th, 2017, Andreas Fath completed a swim of the entire 652 – mile length of the Tennessee River. The 34 – day swim sets a new world record for the river and is part of a larger scientific endeavor called the “Tenneswim”, which seeks to raise awareness of the importance of water quality on the Tennessee River watershed. Fath, a professor at the University of Furtwangen, Germany, teamed up with project director Dr. Martin Knoll of the University of the South in Sewanee, Tennessee to analyze the waters of the river for over 600 chemicals and a host of other parameters. This effort will provide an unprecedented look at the health of the Tennessee River.

Fath swam an average of about 20 miles per day, with a support crew of anywhere from 9 to 12 people taking care of the sampling, providing food and water to the swimmer, steering him in the right direction, and keeping other boats and jet skis away. An 18 – foot pontoon boat served as the science platform and support vessel, while a sit-atop kayak was used to guide the swimmer. Get a sense for the daily swim/sample routine by watching the video below (link will take you to Youtube).

Results from water samples will become available during the fall of 2017 and will be published on the http://www.tenneswim.org website. These include heavy metals, pharmaceuticals, pesticides, and micro-plastics. Initial results of dissolved oxygen, phosphates, nitrates, chemical oxygen demand and pH are mostly in the very good range. Visual inspection of the river further gives the initial impression of a healthy, clean waterway.

Major sponsors of the Tenneswim are the Tennessee Valley Authority, the Lyndhurst and Riverview Foundations of Chattanooga, and Sweetwater Brewing of Atlanta. Significant support was provided by the Nature Conservancy, the Tennessee Aquarium, Perkin-Elmer Laboratories, Ijams Nature Center of Knoxville, the River Discovery Center of Paducah, the University of the South and the University of Furtwangen.

The Quality of Sewanee’s Drinking Water

img_2897The 2014 water crisis in Flint, Michigan brought forth the realization once again that public water supplies were prone to contamination by dangerous chemicals. In the case of Flint, it was elevated levels of lead that caused alarm. Lead is a toxic metal that can build up in the body over time and can severely affect mental and physical development, especially among children (including lower IQ and increased hyperactivity). When Flint changed its water source from Lake Huron to the more corrosive waters of the Flint River, lead began to leach from the aging plumbing system and entered homes where it was consumed and used for bathing and washing. Some homes showed levels at a staggering 13,000 parts per billion (ppb), well above the Environmental Protection Agency’s (EPA) action level of 15 ppb. The shock continued as other communities discovered elevated lead levels in their water supply systems. The state of Maryland found that seven primary and secondary public schools had high levels of lead in their drinking water. Soon municipalities around the country were scrutinizing their water supplies more closely.

Lead in water doesn’t just get there from corroding pipe systems that are made of lead. Many locations around the world have naturally occurring lead in rock, sediment and soil. If groundwater in these areas is the drinking water source, then lead contamination can be expected. Lead mines often lead to groundwater contamination, as was the case in Picher, Oklahoma, which was declared a superfund site by the EPA. Its more than 1500 residents were mostly bought out by the federal government and the municipality has been a ghost town since its last resident died in 2015. Lead contamination from non-water sources, such as old lead paint in houses, may prove to be an even larger threat that water-borne lead.

What about the quality of water in Sewanee? If you are on the Sewanee Utility District’s (SUD) water supply system, then your water comes from our reservoir lakes (O’Donnell and Jackson). This water has either flowed across the ground or leached through the soil and rock into the reservoirs. Happily, the substrate in the area is very low in metals that are of concern in drinking water, including lead. After cleaning and chlorination at the filtration plant the water is sent on its way through pipes to town buildings. The pipes are made of various metals and plastics that could contribute some of their constituent materials to the water. One of my environmental science classes recently had tap water analyzed that was sampled from 24 University buildings (no private homes or businesses were sampled). The results indicate very low concentrations of 59 inorganic elements (metals) commonly found in tap water. Not only were metals well below the maximum allowable levels for drinking water as outlined by the EPA, but some metals of particular concern, like lead, were at such low levels that they could barely be detected.

Iron, which is classified by EPA as a secondary contaminant, can be a nuisance in well and lake water on the Cumberland Plateau, staining laundry and plumbing fixtures pink. It is found at such low levels in our tap water that one would have to drink about 180 liters of it to get the same amount present in a single typical, iron-bearing children’s vitamin. This is the most extensive sampling ever done for inorganic elements in tap water on the campus (note that other contaminants and biological components were not analyzed). The results were shared with the Sewanee Utility District and will contribute to a much more complete picture of Sewanee’s drinking water quality. Bottoms up!

Drought Relief



Abbo’s Alley stream in Sewanee flows with stormwater from the recent rains.


Lake Cheston in Sewanee, Tennessee on Nov. 13th.

Rain has finally arrived on the Cumberland Plateau! A total of almost 8 inches of rain fell in Sewanee from the night of Nov. 28th through the morning of Dec. 6th. What impact has this had on the area’s lakes and groundwater?

There has been an increase in lake and groundwater levels in the Sewanee area that may signal that we are moving out of the worst parts of the drought. Much depends on how much rain will fall over the winter. Let’s take a look at the 130 million gallon (mg) Lake Jackson, which serves as Sewanee’s primary reservoir. This lake was 15.1 feet below lake-full levels on October 25th and dropped to 20 feet below lake-full levels on November 26th. On Dec. 7th, after the rains, the lake stood at 19 feet below lake full levels, indicating that the rain has just begun to reverse the decline in the level of this lake. Sewanee removes about 350,000 gallons of water per day from this lake for municipal use. Last year at this time the lake was only 3 feet lower than capacity. In November of 2007 (during the great drought) the lake was  30 feet below lake-full levels, but recovering from an all-time low of 34 feet in October of that year.


Lake Jackson in Sewanee on Oct. 25th at 15 ft. below normal.


Lake Jackson on Nov. 26th at 20 ft. below normal. Red arrow shows level on Oct. 25th.


Lake Jackson is part of Sewanee’s reservoir system, which is administered by the Sewanee Utility District (SUD). Its waters are pumped first into the smaller reservoir of Lake O’Donnell (80 mg), before water is treated at a filtration plant and sent on for public consumption. If the drought becomes severe enough and these lakes become critically low, then water can be pumped into Lake Jackson from nearby Lake Dimmick (230 mg).


Sewanee’s reservoir system. Lake Dimmick can be tapped if levels of other lakes become critically low (mg = million gallons).

On Nov. 17th, SUD estimated that Sewanee had 140 days of water remaining (does not take into account Lake Dimmick). Neighboring Tracy City had 7 months of water left, while Monteagle had yet to make a statement about their days remaining. The Tennessee Department of Transportation closed the Monteagle Interstate 24 rest area during the week to conserve Monteagle’s water.

Other non-reservoir lakes in the area have rebounded slightly. Lake Cheston was 2.3 feet below lake-full levels before the rain and is 1.2 feet low as of Dec. 7th.

Since all groundwater is fed by rain, we are also experiencing record declines in the water table and in the flow of springs. The water level in the well at Snowden Hall on central campus has rebounded 2 feet since the rains (Dec. 7th), but is still 4 feet lower than at the same time last year. Tremlett Spring in Abbo’s Alley was flowing at near record low levels of 6264 gallons per day (down 790 gallons per day in the last four weeks), but has rebounded with the rain to 6451 gallons per day. On the same date in 2007 (during the great drought) Tremlett Spring was producing 6,171 gallons of water per day. For comparison, an average flow rate for the spring is around 12,000 gallons per day.

Even just after the rain, Bridal Veil Falls (which is spring fed) in Sewanee remained a trickle (below).


Bridal Veil Falls in Sewanee remains a trickle on Dec. 1st after 4 inches of rain.

The likely reason that the rain has not raised water levels in lakes and in the ground as much as hoped is that the soil was extremely dry and was therefore able to absorb most of the water that fell. Now, however, it is more likely that any rain falling in the coming weeks will have a greater chance at raising these levels.

This drought has its origins in the early spring of this year. Since March, we have had a total rainfall of just 27 inches. Compare this to 49 inches for the same time period last year and 29 inches during the great drought of 2007. Sewanee has been recording rainfall data since 1896. The driest years on record are 2007 and 1941. This year stands a good chance of becoming one of the driest ever.


Tenneswim: Swimming the Tennessee River to Raise Water Quality Awareness

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The Tennessee River. Photo by Betsy Boden.

During the summer of 2014 Andreas Fath broke the world record for speed swimming the Rhine River from its source in the Swiss Alps to its confluence with the North Sea. This 28 day, 765-mile swim was more than an exceptional athletic achievement. Fath took daily water samples that provided an unprecedented look at the quality of water within this historic river.

Partnering with the University of the South, the Tennessee Aquarium , the University of Georgia River Basin Center, the Nature Conservancy, the Tennessee Valley Authority, and the Lyndhurst and Riverview Foundations of Chattanooga, this University of Furtwangen (Black Forest of Germany) Professor will now set his sights on the Tennessee River, which he plans to swim in its entirety in the Summer of 2017. The 652-mile long Tennessee stretches from Knoxville, Tennessee to Paducah, Kentucky where it joins the Ohio River. The first swim day will be July 27, 2017, starting at the Ijams Nature Center near Knoxville, Tennessee. This is the confluence of the French Broad and Holston Rivers, the official beginning of the Tennessee River. We anticipate that the swim will take about 30 days.

Fath’s endeavor will shed important light on the quality and health of the Tennessee River with the main goal of raising public awareness of water quality in the Tennessee River basin. An extensive team of researchers and students will accompany Fath, collecting daily water samples that will be analyzed for pharmaceuticals, pesticides, hormones, bacteria, and heavy metals – over 200 separate chemicals in all. Fath’s own pioneering technique will be used to detect micro-plastic particles suspended in water, to which numerous contaminants adhere. In preparation for micro-plastic sampling, Fath recently took a short raft trip down the Kinzig river by his home town in the German Black Forest. See the video below for that preparatory event:


Additionally, special instrumentation will be attached to the swimmer to permit the location of river sturgeon that were released recently by the Tennessee Aquarium. Fish and other aquatic life will be collected to gauge their health as well. Researchers from multiple institutions will collaborate on the most extensive, interdisciplinary water quality survey to have ever taken place on this river. Graduate and undergraduate students will participate in data collection and analysis, as well as in the organization of this complex endeavor.

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One of dozens of newspaper clippings from Germany showing Fath’s wetsuit used in the Rhine Swim on display in the Stuttgart Museum of Natural History and stating his intention to swim the Tennessee River.

The public will be able to track Fath’s daily progress via a website that will include analytical results.

In preparation for this historic event, Fath recently visited several sites on the Tennessee River and participated in a 10-mile swim race through the Tennessee River gorge outside of Chattanooga.


Fath swimming the 10 mile Swim the Suck race on the Tennessee River in 2015. He finished second overall with a time of three hours and one minute.


For more information and to track the swimmer’s daily progress, visit our website at http://www.tenneswim.org and our Facebook site https://www.facebook.com/TenneSwim/.

To help support this important endeavor, please consider giving at the following Tenneswim crowdfunding site:



Why we’ve pulled the plug on well water on the Plateau


An old, shallow well in Sewanee.


Before we successfully built the first modern reservoirs in the Sewanee area in the 1950’s, well water was an important component of our water supply along with the few perennial springs in the area. The first wells were hand-dug, extending down through the soil and then through as much of the weathered bedrock as the well diggers could manage. These old wells (like the one pictured above) typically ranged in depth from 20 to 35 ft. A rare glimpse into a well behind and old residence on University Ave. and in the woods on “Billy Goat Hill” in Sewanee reveal that the structures were rock-lined and between 3 and 4 feet in diameter (see photo below).

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Interior of a long-abandoned, mostly infilled, rock-lined well in Sewanee. The rock lining presumably extended down through the soil until bedrock was reached.

The rock lining would have prevented collapse of soil into the well and presumably did not extend into the bedrock to any great distance. Upon completion, the well was capped with a lid and a pipe moved water from the well bottom to the surface via a hand-operated pump. These old wells were problematic for two main reasons. The first is that their shallow nature meant they would run dry when the water table dropped due to drought or seasonal decline during dry periods of the year (summer and fall). The second issue is that they were not sealed off (or cased-off in well driller speak) from the surface. That meant that surface water, along with any contaminants it carried, could easily infiltrate the well. During heavy rains one can sometimes hear water pouring from the surrounding soil down into these old wells. This was not a good arrangement if a privy or concentration of animals was near the well.

Today wells are drilled with much greater ease using compressed air drilling techniques, so that a well over 100 ft. deep, penetrating hard sandstone, can be completed in just a few hours.


A 100 ft.+ deep well being drilled on the campus of the University of the South in Sewanee.

These wells are cased off for the first 21 ft., so that there is little chance of surface water  entering the well. Below are field notes showing the construction of a modern well in Sewanee:


The field notes show that a 8.5 inch diameter hole is first drilled through the soil and then into the bedrock to a depth of 21 ft. Steel casing (a steel tube) of 7 inches diameter is then placed in the larger hole. The space around the outside of the steel casing is then filled with a bentonite slurry. Bentonite is a swelling clay and forms a tight, waterproof seal around the steel casing. Now a 6 inch diameter hole is drilled to the desired depth below the water table. In most cases the borehole is left unlined, with the firmness of the rock preventing the hole from collapsing.


Steel casing of a modern water well protruding from the ground.

Why then, with this efficient method of providing safe access to groundwater, have most people on the Plateau chosen to opt for reservoir water as their drinking water source? The answer lies with issues related to both water quantity and quality. A quick glance at the water well drilling records maintained by the state of Tennessee (or in conversations with well drillers) reveals that the average yield of wells on the Plateau is between 3 and 5 gallons per minute. This might prove satisfactory if one has the ability to store the well water in a large tank, but this does not suffice for a household pumping the water directly from the well into the house. The reason for these low yields is primarily due to the fact that the sandstones and shales of the upper Cumberland Plateau have relatively low permeability. Water travels through these layers mainly along fractures and one must be fortunate enough to have a well that intersects these fractures. Predicting where these fractures are found in the subsurface is not possible. Compare these yields to those from wells drilled in the valley surrounding the Plateau, where wells often produce from 80 to 100 gallons per minute. This increased production is due to the fact that valley wells are drilled into very permeable limestone that is honeycombed with caves and passageways filled with water. Drilling deeper on the Plateau down into the limestone will not increase yield, since caves and associated passageways do not extend beneath the sandstone cap of the Plateau.

Geologic cross section of the Cumberland Plateau near Sewanee. Rocks above the Raccoon Mountain Formation are relatively impermeable sandstones and shales. Rocks below this layer are chiefly limestones with good permeability given to them by caves and passageways only in areas not under the sandstone cap.


The second problem with well water on the Plateau has to do with reduced quality because of high levels of iron. Now, iron is not considered a primary contaminant in drinking water by the Environmental Protection Agency (EPA). Rather, it is classified as a secondary, or nuisance contaminant, causing stains on bathroom fixtures, turning white laundry pink, and clogging water filters. The general rule of thumb is that the greater the depth from which water is drawn from a well, the higher the iron content will be. This is due to the fact that deeper groundwater contains less dissolved oxygen than shallow water. Dissolved oxygen makes the iron precipitate out of solution (turn solid) and settle out of the water. The same trend is seen in spring water. Shallow springs (like Tremlett Spring in Abbo’s Alley or Hat Rock Spring) are very low in iron. These springs emanate from the Sewanee Conglomerate (see cross section above), which sits on top of the Plateau in the Sewanee area. Deeper springs that emanate from the underlying Warren Point Sandstone have much higher levels of iron and have historically been called chalybeate.


A chalybeate (high iron) spring emanating from the Warren Point Sandstone in Sewanee. As the oxygen-depleted groundwater meets the air, the iron precipitates out as a solid.

The ultimate source of all the iron in the groundwater is from the weathering of iron-bearing minerals in the sandstone.

So, due to low yields and high iron, the vast majority of people on the Plateau have opted for reservoir water (if it was available to them) instead of well water.