The study found that no significant environmental effects are anticipated from construction activities to correct seepage in an earthen embankment at Boone Dam, according to TVA, and any short-term environmental impacts will end once the project is complete.
TVA will restore any area impacted to pre-construction condition.
TVA issued a draft version of the environmental assessment late last year and held a meeting at Daniel Boone High School on Nov. 5, 2015.
The public had 33 days to review and comment on the draft EA.
TVA's responses to the public comments are included in the final report, which is available here.
A sinkhole occurred in a non-public parking area on the downstream side of Boone Dam in October 2014. It was filled. Shortly afterward sediment-filled seepage was discovered on the riverbank downstream of the dam.
That’s when TVA announced a quicker-than-usual draw-down to winter levels. Citing safety concerns and continuing work to solve the seepage issue, TVA later announced the lake’s level would not be raised this year.
A long term repair plan announced by TVA in late July — with an estimated completion time of five to seven years and a price tag of $200 million to $300 million — calls for a three-phased repair that will culminate with construction of a “concrete cutoff wall” within the earthen portion of the dam.
It will be include a multi-stage combination of grout injections and concrete.
When completed it will be several feet thick, extend underground as much as 250 feet, and run the entire length of the crescent-shaped earthen section — from the concrete section of the dam, to the parking lot near the beach area.
The environmental review process required by federal law was expected to be completed this month — and the three-phase repair process will begin immediately afterward, TVA officials have said.