Life History Of A Major Impoundment

In 1967, a major impoundment to contain phosphate tailings was built near Columbia, TN. Precise records were maintained on the behavior of the impoundment throughout its 20-year active life. The volume of the impoundment was determined. The DNT (dry net tons) of solids added to the impoundment were continuously measured. The rise of the mud line in the impoundment was measured monthly. The density of the settled strata was determined, as required to understand the behavior of the settled tailings. And experiments were per formed to increase the settled density of the clays. The impoundment is currently being retired and stabilized. It covers more than 400 acres and the settled muds are almost 200 ft thick. The clays have been sufficiently solidified with electroendosmosis to support the growth of cypress trees. More than three milllion trees are being planted.