Among the meandering waterways of the Tennessee Valley lies the Kingston Fossil Plant, sited at Watts Barr Lake reservoir, about 60 km (40 mi) west of Knocksville, a well-known spot for birdwatching. The plant converts five million tons of coal a year into electricity for the atomic reactor at nearby Oak Ridge and when it was built in the 1950s this was the largest plant of its kind in the world.
In the main plant, pulverized coal is burnt to make steam; the process leaves a large residue of tale-line ash, known as ‘coal fly ash’, which is mixed with water to stabilize it. Once the sediment has settled it is removed to a ‘dredge cell’ to dry out.
On December 22 2008, after days of heavy rain, a section of the massive clay walls of the dredge cell gave way, releasing millions of gallons of coal fly ash slurry and causing the biggest-ever environmental disaster of its kind in the USA. The slurry flowed along the river valley, damaging houses and power lines in its path, and covering an area of more than 1 sq km (0.5 sq mi) in a thick layer of grey sludge. Inevitably, the run-off flowed into the local waterways, killing thousands of fish and poisoning the bird life.
The plant’s owners, the Tennessee Valley Authority, quickly reassured residents that water upstream still met drinking water standards and that the slurry was not toxic – independent tests suggested significant levels of toxic metals – and promised an immediate clean-up. They faced outcry, accusations and demonstrations from local people and environmental groups nationwide and were blamed not only for the spill – reportedly, the unlined tank had undergone repairs for leaks regularly for some years but also for disposal methods generally.
When: December 22 2008
Where: Kingston, Tennessee, USA
Toll: Fortunately, residents in the area were evacuated before the spill reached their homes, but the environmental damage has been enormous.
You should know: The TVA emphasized the importance of regaining the public’s trust. Among the goals set out in their year-on report was the provision of ‘health assessments’ for local people.