Experience with Tailings Dams in the Georgia Kaolin Belt

The Kaolin Belt of Georgia extends east-west across the central section of the state at the geologic "Fall line" between the Coastal Plain and the Piedmont Plateau. Within this region, the major kaolin producers mine and process kaolin clay for a variety of uses. A significant amount of waste is generated from the mining and refining processes. As a result, tailings dams are required to impound the generated process waters and the tailings. Tailings dams for the kaolin mining and processing industry are constructed as water retaining structures from native soils. The dams are typically 30 ft. to 100 ft. high and fill with tailings in about 5 to 15 years.
This paper describes Golder Associates' experience over the last 25 years in the design, construction management, and safety evaluation of more than 40 tailings dam structures. Typical geological formations and dam foundation conditions in the Kaolin Belt are described and data is provided on the parameters of the soils that are available for dam embankment construction. Typical dam cross-sections and details of spillways, decants, and drains are also described.
In addition, the paper discusses typical maintenance concerns associated with kaolin tailings dams. Typical safety concerns including excessive seepage, slope instability, spillway erosion, and cracks in outlet pipes are described along with descriptions of the repairs that have been required.