Geotextile reinforced sludge pond capping

AUTHOR: K.S. Tong

In recent years, increasing attention has been given to the closure of sludge ponds due to environmental concerns and regulatory demands, particularly impacting mining, chemical, and utility companies. Unclosed tailing ponds pose potential environmental hazards. These sludge ponds often contain very soft deposits, preventing construction vehicles from accessing the pond surface. Capping sludge ponds using geosynthetics has evolved and become standardized, offering a time and cost-effective strategy. This method involves covering the entire area of the sludge pond with reinforcement geotextiles, enabling lightweight earthwork equipment to access the site without requiring pretreatment of the soft deposits. The geotextiles function through a tension membrane effect in the soft foundation, accommodating large differential deformations. Innovative installation and backfill techniques have been developed based on specific site conditions. Several case studies of successful applications of reinforcement geotextiles used in sludge pond capping will be discussed.