Copper Basin Mining District

EPA ID: TN0001890839
Polk County, TN
Site Repository:
Ducktown Chamber of Commerce
134 Main Street
Ducktown, TN
Historical Photographs
Environmental Legacy Photographs
Site Documents (Adobe PDF Reader Required):
EPA Proposal for Apache Blast Cleanup photos

Site Background: The Copper Basin Mining District Site (CERCLIS ID TN0001890839), hereinafter, referred to as the "Copper Basin" or the "Site" is located in southeast Tennessee in Polk County, and northern Georgia in Fannin County, near the state border with North Carolina. The Copper Basin is the site of extensive former copper and sulfur mining operations that date back to the early 1800s. For more than 150 years, numerous companies and individuals were involved in various mining, refining and manufacturing operations in the area. Historically, over 30 square miles of Polk County in southeastern Tennessee and Fannin County in northern Georgia were a deforested, barren, eroded landscape caused by copper mining and sulfuric acid processing. Over the past 25 years, various government agencies and private parties have taken steps to stabilize and re-vegetate this large area. Mining operations ceased in 1987, and sulfuric acid production was discontinued in 2000. Mining and related activities have resulted in the environmental degradation of portions of the Copper Basin, including the North Potato Creek Watershed, the Davis Mill Creek Watershed, and parts of the Ocoee River. Waste materials from mining and processing activities remain as sources of contaminants in the form of acidic drainage and high levels of metals in the soils, sediments and surface waters of the watersheds that drain into and impact the Ocoee River. Acidic conditions and leaching metals have impaired water quality and deforestation has resulted in severe erosion. PCB containing oils have been released to the environment from abandoned transformers. Abandoned and collapsing mine works and other deteriorating facilities and waste piles also pose significant physical hazards. In addition, the lack of a healthy soil structure and the poor quality of riparian and upland ecosystems contribute to poor surface water quality. This has caused the degradation of large portions of the 10,000 acre North Potato Creek and the 3,000 acre Davis Mill Creek Watersheds and 26 miles of the Ocoee River. The two creeks that drain the Copper Basin Mining District site, when left untreated, were releasing over 8,600 pounds of metals and greater than 19,000 pounds of acid into the Ocoee River every day.

Cleanup Progress:
In January 2001, the story of the Copper Basin changed from environmental degradation to environmental restoration. The EPA, the Tennessee Department of Environment and Conservation (TDEC) and one of the potentially responsible parties, OXY, USA and its corporate affiliate Glenn Springs Holdings, Inc. (GSHI) entered into a Memorandum of Understanding and a series of enforceable state and federal legal agreements and orders. These agreements are designed to provide for immediate action in the short term in order to protect the Ocoee River and begin the long term environmental restoration of the Copper Basin Mining District site. Clean up of this unusual mining mega-site via the Superfund Alternative site clean up process is a success story of unprecedented teamwork whose numerous accomplishments over the last seven years have achieved the goal of protecting the Ocoee River as well as taking major steps toward the long term goal of environmental restoration.

Davis Mill Creek Watershed:
GSHI has implemented a series of EPA removal orders in the Davis Mill Creek Watershed. GSHI refurbished the existing Cantrell Flats Wastewater Treatment Plant and began collecting and treating the acid and metal laden waters of the creek on November 18, 2002. The plant also collects and treats associated underground mine waters as well as the contaminated storm water at the existing industrial facility. Since that date GSHI has completed the installation of the Belltown Creek and the Gypsum Pond Creek diversion systems to route clean waters around the most heavily contaminated parts of the watershed thus reducing volume of water requiring treatment. Additionally, the three existing dams in the watershed have been upgraded and modified to detain contaminated storm water for treatment. In September 2005, GSHI assumed responsibility for the Remedial Investigation and Feasibility Study (RI and FS) in Davis Mill Creek Watershed. The draft RI is scheduled for completion in Summer 2008. The draft FS is scheduled for completion in Summer 2009. A surface water Record of Decision (ROD) for Davis Mill Creek is scheduled for Summer 2010. Additionally in 2005, the removal of 47,000 cubic yards of slag from the Apache Blast area located adjacent to the Ocoee River was completed. The slag was placed at the Mary Mine and restoration of the Mary Mine area was completed. In September 2006 studies determined that 1900 pounds per day of metals and acidity continue to discharge to the Ocoee River. Additional removal actions are on going for 2008 to alleviate the remaining discharge of contamination to the river. One removal action will extend the Belltown diversion system all the way to the Ocoee River to bypass uncontaminated water. Two additional retention dams will be built to detain and treat the remaining contamination. One dam will be built at the mouth of Davis Mill Creek to capture remaining contaminated base flow and another upstream to detain and treat contaminated storm water. The entire system will detain and treat contaminated water up to a 10-year 24-hour storm event of 5.7 inches of rainfall. Construction of the Pipeline and dams has begun this fall and should be completed in 2009. From November 18, 2002 until July 2008, the Cantrell Flats wastewater treatment plant has removed a cumulative 15,709,000 pounds of metals (iron, zinc, manganese, copper, lead, cadmium) and neutralized a cumulative 27,826,000 pounds of acid from the creek that would have otherwise flowed into the Ocoee River.

North Potato Creek Watershed: The TDEC Commissioners Order for North Potato Creek Watershed established biological integrity of the watershed as its long term goal and requires shorter, interim remedial actions to protect the health and safety of the public and the environment. GSHI has completed or is in the process of completing these actions. These include capping the lead contaminated soil at the site of the former Isabella chamber acid plant and covering and re-vegetating the abandoned slag dump also at Isabella. The 300-acre tailings pond was re-vegetated with native grasses and over 100,000 trees have been planted. PCB contaminated equipment and soils were removed from 10 different areas across the watershed. Over 6 miles of 8-foot tall, barbed wire topped chain link fencing and subsidence monitoring equipment have been installed around 7 different areas of abandoned and collapsing mine works. Additions and modifications to the experimental passive wetlands system have been completed. A comprehensive inventory of acid generating materials and hazardous substances associated with historic mining in the watershed has been conducted. Removal of non-hazardous acid generating materials from the watershed has resulted in placement of over 315,848 cubic yards of materials into the Isabella Mine Pit for sub-aqueous disposal. In 2007 and 2008, numerous remedial activities at the London Mill Flotation Plant Site were completed including demolition of buildings, waste removals, initial dredging of the retention pond, grading and re-vegetation, storm water diversions, filling and capping of the plant basement, installation of an infiltrator leachate collection system and installation of an impermeable cap at the concentrate storage pile. Additionally in 2007 and 2008 remedial activities at the former Isabella plant site are nearing completion including demolition of buildings, waste removals and capping.
EPA required additional short term actions in the North Potato Creek watershed to temporarily alleviate the contaminant discharge of North Potato Creek to the Ocoee River while long term actions under the state voluntary clean up program proceed. GSHI conducted a study and agreed to evaluate alternative approaches to temporarily alleviate contaminant discharge to the Ocoee River. This study resulted in the selection of a lime treatment plant to be constructed near the mouth of creek at the South Mine Pit. Construction of the plant is complete and operations began January 10, 2005. The plant will remove 90 percent of the dissolved metals of ecological concern from the creek water and will raise pH of the discharge of the creek to the river from 3.3 to greater than 7.0; thus, virtually eliminating the historic adverse impact of North Potato Creek. Additionally, the North Potato Creek water treatment plant treats mine water from the Tennessee / Cherokee and Boyd / Central Mine works that are in direct hydraulic connection to the South Mine Pit. In 2007, mine water from the Mcpherson and Isabella mine works were routed to and are also treated at the plant. From January 10, 2005 to August, 2007, the North Potato Creek water treatment plant has removed 514, 973 pounds of metals and neutralized more than 1,378,000 lbs. of acid.
Since 1991, a cumulative 25 billion gallons of water have been treated at the various water treatment plants in the Copper Basin. They have removed 16 million pounds of metals and neutralized 28 million pounds of acid from the creeks and mines that would have otherwise flowed into the Ocoee River.

Ocoee River: EPA is in the process of completing a phased Remedial Investigation/Feasbility Study (RI/FS) of 26 miles of the Ocoee River impacted by the site. The study area includes 3 TVA impoundments that are managed for recreation, flood control, and white water recreation. The study initially documented conditions in the Ocoee River prior to water treatment at the confluences of Davis Mill Creek and North Potato Creek. The RI/FS focus has now shifted to evaluation of more chronic ecological impacts associated with resultant sediment, pore water, and surface water quality. A two-dimensional sediment transport model has been calibrated to assist in development and evaluation of protective sediment and water level management strategies. The Final RI Report was approved and released to the public in May 2008. EPA has initiated technology screening and remedial alternative development to address the residual risks identified in the RI Report. A Final Feasibility Study is anticipated by Summer 2009.

Copper Basin Mining District

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