The Tennessee Department of Environment and Conservation (TDEC) today announced a new precautionary fish consumption advisory on Parksville Reservoir on the Ocoee River in Polk County. This lake is also known as Ocoee Number 1.
This advisory is due to elevated levels of polychlorinated biphenyls (PCBs) in catfish species. Other fish species are not impacted.
TDEC advises that pregnant women, nursing mothers, and children avoid eating the fish species included in the advisory and that all others limit consumption to one meal per month. Other recreational activities such as boating, kayaking, swimming, wading, and catch and release fishing carry no risk. Rafting on the Ocoee River does not expose citizens to PCBs.
“By all measures, the Ocoee River including Parksville Reservoir is one of Tennessee’s most dramatic water quality success stories,” TDEC Deputy Commissioner Greg Young said. “Forty years ago, Parksville Reservoir was so toxic that few fish could live in it and local residents knew not to bother fishing there. There were no fish to catch in the lake because of the over 100-year history of water quality impacts from copper mining in the Copper Basin.
“However, modern environmental regulations and the restoration of the Copper Basin led to enough water quality improvement in the Ocoee that fish began to return to Parksville Reservoir. Now fish thrive in the lake but have been exposed to the legacy chemicals in the sediment. One of these chemicals is PCBs.”
In the last 20 years, the Tennessee Valley Authority (TVA) collected and analyzed fish in Parksville Reservoir in 2001, 2003, 2005, 2007, 2009, 2011, 2014, and 2017. These fish tissue data are the basis of the new advisory. The lake will again be sampled in 2020.
“We issue these advisories so the community can make informed decisions about whether or not to consume the fish they catch,” Young said. “Unlike ‘do not consume’ advisories that warn the general population to avoid eating fish from a particular body of water altogether, precautionary fish consumption advisories are specifically directed to sensitive populations such as children, pregnant women, nursing mothers and those who may eat fish frequently from the same body of water.”
TDEC will post warning signs at public access points on Parksville Reservoir and will work with the Tennessee Wildlife Resources Agency, the Tennessee Valley Authority, and the Cherokee National Forest to communicate this information to the public.
The Tennessee Water Quality Control Act identifies the commissioner of the Department of Environment and Conservation as having the authority and responsibility to issue advisories for either water contact hazards like pathogens or excessive health risks due to the accumulation of contaminants in fish or shellfish. Tennessee’s General Water Quality Criteria provide additional guidance regarding the conditions under which advisories may be warranted.
There are two types of fish consumption advisories issued by TDEC based on the levels of contaminants present in fish tissue. “Do not consume” fishing advisories are issued when levels of contaminants in fish tissue would represent a threat to the general population. Precautionary advisories are issued when contaminant levels are lower but would still pose a risk to sensitive subpopulations such as children, pregnant women, nursing mothers and those who eat fish frequently from the same body of water.
Polychlorinated biphenyls are a group of man-made organic compounds. Because of their stable chemical structure and resistance to heat and pressure, they were widely used as cooling and stabilizing oils for capacitors, motors, transformers, and other electrical equipment. Once thought to be harmless, they were later classified by the U.S. Environmental Protection Agency (EPA) as a “probably human carcinogen.” EPA banned PCBs for most uses in the United States in 1979.
While PCBs were banned over 40 years ago, their stable chemical structure makes them very persistent in the environment. They are commonly found in reservoirs, especially in areas where transformers or other electrical equipment was in significant use, like hydroelectric facilities or certain industries.
Where new advisories have been issued, TDEC will immediately begin the process of putting up signs at primary public access points. TDEC works in partnership with the Tennessee Wildlife Resources Agency to communicate information about fishing advisories.
For a complete listing of Tennessee’s current fishing advisories plus additional information about the advisory issuance process, visit: https://www.tn.gov/content/dam/tn/environment/water/documents/water_fish-advisories.pdf
An EPA website has additional information about mercury at http://www2.epa.gov/fish-tech/epa-fda-advisory-mercury-fish-and-shellfish.