The US Environmental Protection Agency and Tennessee Valley Authority are extending their dredging operations in the Emory River to remediate the impact of the massive coal ash pollution at Kingston in December 2008 as it weighs up long-term remediation options.
Around 5.4m cu. yd. of fly ash sludge is believed to have escaped from the west ash storage facility at Kingston causing environmental devastation over a wide area.
Dredging operations have been underway since last August and six miles of the river have been closed to river traffic.
In January the Agency issued an engineering evaluation and cost-analysis report on non-time-critical remediation alternatives at the site, including stabilization of the failed cell.
A separate report on residual ash in the river system is due later.
The report examines three alternatives:-
- excavating the embayment, disposing 2.8m cu. yd. off-site and grading and closing the dredge cell;
- excavating the embayment and part of the cell, disposing 6.8m cu. yd. off-site and grading and closing the cell;
- excavating the embayment, disposing of 2.5m cu. yd. on-site and closing the dredge cell.
The Agency says all three would restore the embayment area to pre-spill conditions but have different levels of foundation treatment so the perimeter dike system would be stable in the long-term.
Other options were rejected.
