EPA is proposing actions to improve the water quality of the Ocoee from Copperhill to Dam No. 3, at Dam No. 3, and at the upper reach of Parksville Dam. The key problem is sediments contaminated by the historic erosion of land from the Copper Basin mining areas. A plan of action has been released showing alternatives that were considered and the preferred alternatives, with a comment period from June 17 – July 18. There will be an Open House and Public meeting at the Glenn Springs Holdings office June 23, 5-7 p.m., with a presentation at 6 p.m.

The preferred alternative calls for monitoring systems at all three sites, with dam controls to be used to control sediment at No. 3 and higher water levels year-round at Parksville Reservoir to keep the sediment underwater.

From the late 1800s until the 1980s, tens of millions of cubic yards of soil were eroded and transported to the Ocoee River, along with mining and industrial wastes. As a result, aquatic life and habitat were significantly degraded. Remedial actions taken by Glenn Springs Holdings, Inc., have led to improved water quality through removal of contaminants, but sediment at several locations shows chronic risks to aquatic life from elevated metals and acid.

EPA notes that PCB levels in fish tissue fro the eastern park of Parksville Lake could present a cancer risk for 1 in 10,000 if people, on average, eat more than 1.5 meals per month of channel catfish or 12 meals per month of largemouth bass. The cleanup goal is the acceptable risk range of less than 1 in 100,000.

There is no additional risk to human health. The risk assessment included recreational users, whitewater guides, fishermen, and Ocoee Whitewater personnel and visitors. However, there is risk to aquatic life, such as aquatic insects that are the primary food supply for fish. Metals and acid in the sediment delta of Parksville Lake inhibit the growth of aquatic insects and fish spawning and juvenile rearing, and the delta does not support vegetation.

During the winter months, TVA lowers the water level in Parksville 8 to 10 feet, which exposes the sediment delta that formed when erosion from the Copper Basin went unchecked. When the upper layer of these sediments is exposed to air, chemical reactions form acid and dissolve heavy metals in the sediment. The goal of the cleanup plan is to keep these sediments under water except for normal short-term fluctuations, thus lessening exposure to oxygen and release of metals. A consistent water cover would also prevent the annual flushing of metals that occurs when the pool level is lowered in winter months. The recommendation calls for keeping the water level at 834 feet above sea level, about seven feet higher than the current winter pool.

EPA’s preferred alternative is to accomplish this through the existing system of flashboards and superboards. TVA would be required to annually inspect the system and completely replace it every three to five years. Other alternatives for maintaining a consistent water level were by installing a pneumatic gate system or development of a wetland on the sediment delta. The wetland idea would require a lower water level, which could impact recreation on the lake. Another alternative called for dredging to remove enough sediment so the delta is at an elevation below the existing winter low pool. Dredged materials would be moved to deeper portions of the reservoir.

For the river between Copperhill and Dam No. 3, EPA is recommending monitored natural recovery, allowing naturally occurring processes to contain, destroy or reduce the availability of the contamination. There would be a monitoring program to document changes in identified risks. If there is no risk reduction, additional action could be considered. Another alternative called for natural recovery and enhanced sediment capping with in-stream structures. This was seen as difficult to implement because of difficult access to the river.

For Ocoee No. 3, the recommended action is monitored natural recovery with hydraulic controls. In addition to monitoring the natural recovery, the plan would require TVA to develop a plan to manage the discharge of water through the dam in a way that minimizes release of the deeper, more contaminated sediments behind the dam. The Tennessee Department of Environment & conservation would have to approve TVA’s plan.

Craig Zeller with EPA, who is in charge of the planning, said Glenn Springs Holdings will be responsible for the costs of the work and monitoring. TVA has signed off on the preferred alternative.

EPA, in consultation with TDEC, will select the final alternatives after considering all input submitted during the 30-day comment period. The preferred alternatives can be modified or new remedies developed based on new information or public comments.