Real results from artificial soil

University of Missouri-Columbia and Continental Cement Company have initiated an in-depth monitoring program to assess the long-term effectiveness of ‘artificial soil’ as a waste containment system.

In 2002, the University of Missouri-Columbia and Continental Cement Company launched an innovative waste containment strategy using “artificial soil” as a sustainable and environmentally responsible waste containment system.

Two years later, more than 80,000 tons of waste materials have been placed in the system’s test site and nearly four acres of mined land have been successfully reclaimed. Now, researchers have initiated an in-depth monitoring program to assess the long-term effectiveness of this artificial soil.

“Our research is designed to address water quality issues associated with this waste containment strategy,” said William Likos, assistant civil engineering professor at MU. “We hope to show people that certain kinds of material in local soils can be used to help create environmentally stable and sustainable soil-biological systems from industrial and urban waste products.”

Recycled organic and mineral waste materials, such as sewage sludge, yard waste, power plant ash and cement kiln dust (CKD), are blended to form a substance that simulates natural soil. The “soil” is placed in a thick layer over a CKD layer and is seeded with grass and trees to create a self-sustaining waste cover.

Likos and a team of MU researchers constructed a full-scale test pad and fitted it with moisture content sensors, temperature sensors, water collection devices and a surface rain gauge to quantify the rate and depth of rainfall infiltration into the system. The goal, Likos said, is to show that the artificial soil layer prevents precipitation from seeping into the underlying CKD, which would be harmful to the surrounding ecosystem.

“This project will provide quantitative evidence to support widespread use of similar artificial soil programs as alternative cover systems for more general land-filling and waste disposal applications throughout and beyond the state of Missouri,” Likos said.

The test pad will be monitored for one year to evaluate the cover’s performance over a full cycle of precipitation and temperature extremes. According to Likos, preliminary findings point to artificial soil as a viable alternative for widespread use as an environmentally friendly waste disposal and containment strategy.