Hazardous Metallic Elements in Tennessee Copper Basin Stream Sediments: Sources, Concentrations, and Distributions

1
Hazardous Metallic Elements in Tennessee Copper
Basin Stream Sediments Sources, Concentrations,
and Distributions
Mayfield, Aaron Anderson, Brad Hornaday, Jake
Marston, Bart Cribb, J. Warner, Department of
Geosciences, Middle Tennessee State University,
Murfreesboro, Tennessee
Sampling and Analyses Procedure Sampling
was conducted for analyses in various streams and
rivers feeding into the Copper Basin watershed
being sure to gather samples from within the
watershed and outside the watershed as background
samples from which to compare results. Sites were
chosen using four 7.5 quadrangles covering the
Copper Basin Area Ducktown Quadrangle, Isabella
Quadrangle, Mineral Bluff Quadrangle, and the
Epworth Quadrangle. Each sample was
collected using a plastic spoon with the sediment
collected deposited into a Ziploc plastic bag
which was then deposited into a second plastic
bag. Samples were collected from both stream
channels and banks. Disposable plastic spoons
were used in order to both prevent major element
contamination through use of a metal instrument
and to prevent cross-contamination between
samples. Once collected, each sample was labeled
and a GPS coordinate was then obtained for each
sample site. Each sample was then processed into
pressed pellets and analyzed with the Oxford MDX
1800 X-ray Fluorescence spectrometer.
Abstract The Tennessee Copper Basin, southeast
Tennessee, is an area affected by over 100 years
of mine-impact degradation to regional landscape,
flora, and fauna. Early mining and ore processing
techniques resulted in stripping of the landscape
for wood fuel and the production of atmospheric
sulfuric acid. The resulting acidic rains and
oxidation of bedrock sulfide minerals sterilized
the soil, resulting in long-term erosion of
metallic elements such as arsenic (As), lead
(Pb), and uranium (U) into the local watershed.
Although mining operations ceased in 1987, the
Copper Basin still exhibits signs of
environmental stress. This focus of this
research is geochemical study of Copper Basin
stream sediments to determine which
environmentally hazardous metallic elements are
present at concentrations higher than natural
background, and the sources of those sediments.
The research has direct implication to long-term
environmental and health studies of the Copper
Basin. According to the U.S. EPA, human
consumption of As may cause illnesses, ranging
from cardiovascular ailments to skin disease, or
even death. Consumption at lower concentrations
may cause illnesses ranging from cardiovascular
ailment to skin disease. The consumption of Pb on
both children and adults are well known, and
include mild headaches, reproductive disorders,
and long-term damage to the brain and nervous
system. U is a radioactive element, which even at
very low concentrations may present cancer risks.
Our research identifies the primary sources of
Copper Basin metals-bearing sediments as old mine
tailings deposits and bedrock exposures. X-ray
fluorescence spectrometry (XRF) analyses of
sediment samples collected downstream of tailings
ponds and bedrock outcrops show the presence of
As 44 ppm, Pb 244 ppm, and U 32 ppm.
Additional metals present are copper, zinc, and
nickel. The geographic distribution of these
metallic elements also is being assessed as a
measure of whether their concentrations change
during downstream sediment transportation.
Results Conclusions
Potential Tennessee Copper Basin toxic metal
contaminant sources
Photos courtesy of the EPA
History of the Copper Basin Copper was first
discovered in 1843, and just four years later the
copper began to be mined. In the early 1850s,
the mining industry began to boom and wagon
trails were created and more companies moved into
the area to begin mining. The first smelter,
which is used to remove the copper ore from the
rocks, was built in 1854 on Potato Creek. In the
1860s, due to the American Civil War, the mining
industry slowed a bit but did not cease. The
creation of the Marietta and North Georgia
Railway in 1890, which connected Knoxville, TN
and Atlanta, GA, greatly increased copper
production. Copper mining continued throughout
the 1900s up until July of 1987 when the mines
were official closed.
Overview Although numerous studies have been
conducted studying the toxic metal concentrations
in the Copper Basin Watershed, none have focused
on the toxic metal load present in the stream bed
sediments. The purpose of this study is to
determine whether or not toxic elements are
mobile within the stream sediments and how
quickly the toxic metals attenuate with respect
to distance from potential contaminant sources.
This study focuses on five toxic metals arsenic,
cadmium, lead, thorium, and uranium. Through
erection of graphical models, attenuation rates
for these particular toxic elements are
determined, as well as any potential contaminant
sources possibly enriching the sediment load.
Environmental damage in the Copper Basin The
copper mining and smelting industries in the
Copper Basin were the most influential human
activity that was detrimental to the environment.
Logging of the surrounding area to provide fuel
for the open-air roasting of the ore were the
first to cause damage to the environment. The
roasters released toxic sulfur dioxide into the
atmosphere which fell as acid rain when it
precipitated (Quinn 1988). The result of the
lumbering and open-air roasting caused the death
of the vegetation in the area, and with an annual
rain fall of 58 inches, the lack of vegetation
caused the terrain to become even more
susceptible to erosion. By 1907 the sulfur
dioxide fumes had damage an estimated 200,000 to
640,000 acres in the area, and in the center of
the basin was a 7,600 acres of severely eroded
landscape which was completely devoid of plant
life (Quinn 1988). Not only was the vegetation
in the area affected by the mining but the water
quality of the area was also affected. Since the
beginning of mining operations, the Ocoee River
has been contaminated by the mining waste present
in both the water and stream bed sediments
(Muncy). Even though the companies of the Copper
Basin were killing the environment, they were
also trying to sustain it as best they could.

• The presence of toxic metals in Tennessee Copper
  Basin stream sediments is due to erosion from a)
  tailings ponds, b) abandoned mines, c) bedrock
  outcrops
• 2. Lead, Thorium, and Uranium concentrations
  increase in the downstream sediment supply.
• 3. Arsenic and Cadmium concentrations decrease in
  the downstream sediment supply.
• 4. For Cd and As, concentration ranges decreases
  with downstream sediment transport.
• 5. For Pb, TH, and U, concentration ranges do not
  change appreciably with downstream sediment
  transport.

Future Work Future studies will sample
stream water and pH over the sediment sample
sites. Water analyses be carried out using the
inductively coupled plasma mass spectrometer to
determine which toxic metals may be dissolved
into surface water.
Acknowledgments Funding for this research is
provided by StepMT and FRCAC grants to Aaron
Mayfield and Warner Cribb. We gratefully
appreciate the support of the MTSU Undergraduate
Research Center and the MTSU Office of Research.
Funding for the MTSU x-ray fluorescence lab is
provided by the National Science Foundation. We
also thank Ken Rush, Director of the Ducktown
Basin Museum, for his support.
Sample sites in the Tennessee Copper Basin.