Kingston Ash Release
Selenium is a naturally occurring mineral element found in rocks and soil. In low level doses it is actually good for the health; most people are exposed to it daily through food, water and even as a vitamin supplement. TVA’s water quality monitoring has not detected levels of selenium in water in the Kingston area that violate standards, and we’ve seen no evidence that selenium is a problem. Nonetheless, out of an abundance of caution, TVA and the State of Tennessee are continuing their sampling and monitoring.
- Questions have come up recently about whether dredging in the Emory River channel could result in increased amounts of selenium in the river that could possibly affect fish and wildlife. TVA, TWRA, and ORNL have collected fish from the Emory River recently that are being analyzed for selenium and several other metals. Those results are not yet available. TVA’s historical data on selenium in catfish fillets from the general area do not indicate any reason for concern for human health due to selenium.
- TVA’s approach to Phase 1 dredging of the fly ash is specifically designed to ensure that this phase of the dredging activity will not disturb materials that have been in the channel for many years (legacy sediments).
- To date, TVA has not detected increased levels of selenium in water samples from the Emory River in the vicinity of dredging.
- The daily water samples collected by TVA during dredging operations from the plant’s permitted discharge monitoring location have resulted in levels of selenium between 2.5 and 3.5 parts per billion. Those results are similar to selenium concentrations observed in the most recent National Pollutant Discharge Elimination System (NPDES) permit renewal sampling in 2006. That discharge is subsequently diluted 20-fold by the condenser cooling water to a maximum concentration of about 0.2 parts per billion before it is released into the Clinch River.
- The general water quality criteria applied by TDEC and EPA for protection of fish and aquatic life in waters of the U. S. and Tennessee is 5 parts per billion (ppb) for chronic exposure and 20 parts per billion for acute exposure. For a better understanding of chronic and acute exposure click here.
- Nonetheless, out of an abundance of caution and because TVA wants to fully address questions or concerns that residents might have, TVA, with involvement from several other agencies, including the Fish and Wildlife Service, Tennessee Wildlife Resources Agency, TDEC and EPA, is performing additional testing for the presence of selenium as dredging occurs. This will help determine the current levels of selenium and any potential impacts of that level of selenium to aquatic life, including fish.
- Several actions support this effort:
o The Tennessee Department of Environment and Conservation and
the Tennessee Wildlife Resources Agency recently collected fish
tissue samples and are awaiting the final results of the analysis.
- Oak Ridge National Laboratory is conducting studies on the impact of selenium on the health and reproduction of fish.
- TVA is collecting samples of the river water three days a week at 10 locations upstream and downstream in the Emory, Clinch and Tennessee rivers. TDEC is collecting samples at the same locations the other two days a week.
- TVA is also collecting daily samples from any observed dredging plumes during the initial weeks of dredging and analyzing those for selenium and other metals. Results for those samples are beginning to be received by TVA and are undergoing quality control checks before being analyzed and reported.