That sinking feeling.(Living with & Teaching about Karst)(sinkholes)

Sinkholes are usually found in areas where limestone, a sedimentary rock rich in calcium carbonate, is abundant. The construction of highways tend to deviate storm water into retention basins. Basins that have a limestone bedrock will cave in due to the dissolution of the calcium carbonate.

Sinkholes and associated drainage systems cost highway departments, cities and businesses millions of dollars each year.

A recent publication by P.E. LaMoreaux and Associates (PELA), a hydrogeology consulting firm, describes an elaborate sinkhole project in Knoxville, Tennessee.