Aquatic life in Parksville Lake and the upper reaches of the Ocoee will be healthier under a proposal presented by EPA last week.

The agency plan, which could be revised following public comment, calls for monitoring the area between McCaysville and Ocoee reservoir #3, monitoring and eliminating large-scale sluicing from #3, and keeping Parksville Lake at summer levels year-round in order to keep the sediment delta underwater. The key goal is to contain contaminated sediment and keep it from contact with the air, which allows release of toxicity. All sites will be monitored for 30 years.

At a workshop last week, Craig Zeller described the problem, possible solutions, and the preferred alternatives for the three areas. He emphasized that there is no longer any acute toxicity and the river meets water quality standards except for these areas. He said studies showed no problem with use of the water for recreation.

The only problem to human health, he said, comes from eating large amounts of fish from the lake, but the problem areas are impairing aquatic life. Zeller emphasized that there have been significant improvements in water quality as a result of actions taken by Glenn Springs Holdings, which is working on cleanup projects through an agreement with EPA and the Tennessee Department of Environment & Conservation that avoided Superfund designation for the former copper mining site. He said 10,000 pounds of heavy metals are removed daily through a series of treatments plants. All runoff from the Intertrade property, as well as several creeks, are treated before they enter the Ocoee, with 98% of the heavy metals removed.

The problem areas to be addressed are suffering from chronic toxicity from sediment that was washed down from the Copper Basin years ago, before there was any effort to remove the heavy metals.

For Parksville Lake, the proposal calls for keeping the water level high throughout the year. Zeller explained that when the sediment is exposed to air after the winter drawdown, the metals become oxidized. When the water level is raised in the winter, toxic metals may be released from the sediment. In addition, the raising and lowering of the water allows more sediment to slough off and go downstream. Another option included creating a wetland over the sediment delta, but that would require a lower level of water that would affect summer recreation. The idea of dredging and moving the sediment to a deeper part was seen as too expensive -- $11.3 million – to be justified.

Zeller said the higher lake levels could increase the risk of downstream flooding. Modeling scenarios, he said, showed a moderate increase in downstream river levels in the event of a 2-year, 5-year or 10-year flood, but the river would still be in the channel. With a major flood, he said, the higher lake level wouldn’t change the damage. He noted that the Ocoee #1 Dam was not designed for flood storage, according to TVA.

At Ocoee #3, he said, the highest concentrations of heavy metal are in the deeper layers of sediment, but they can be exposed with large releases of water from the dam, as happened during work in 2009 when a lot of the mud ended up at the Ocoee Whitewater Center. The normal releases for recreation, he said, helps avoid sediment buildup by releasing small amounts from the top layer. The plan calls for TVA to develop a plan to avoid large water releases that could release contaminated sediment from the lower layer. Zeller said such a plan had already been ordered by TDEC following the 2009 release.

Asked if the sediment buildup behind the dam posed a problem, Zeller said he was not aware of any instability issues. He said the frequent releases help pull it down a little at a time.

For the upper reach of the river, the plan calls for just monitoring. Zeller said natural recovery is already taking place.

Owen Hensley, who worked for the mining companies for 36 years, said they knew all the contaminants went downstream. He said he didn’t think it would be a good idea to disturb the contaminants that are already there. Zeller said that’s the plan, that they hope to keep it covered.

Several citizens in attendance asked unrelated questions about the cleanup operations. Asked about air quality, Zeller said he did not know of any problems. There is an air quality permit for the calcine trucking operation underway.

On the question of removal of other contaminants, Loften Carr with EPA said sometimes the most cost-effective way is to cap them or the recycle where possible. Asked about geographic instability, Carr said he didn’t think that was a concern in the area.