Forsterite-Treated Silt as a Liner Material

Over time there is a natural accumulation of fine sediments and organic matter in lake beds reducing the depth and water storage capacity of these lakes. Removal of this deposited silt from lake beds is crucial to maintain the health and functionality of these natural resources. Disposing of this dredged silt has been a challenge to local governments and organizations working to restore and rejuvenate lakes in their locality. The use of this silt as a landfill liner material is investigated in this paper. In order to serve its purpose as an efficient liner material, the hydraulic conductivity of silt has to be modified using a suitable additive. This study explores the effectiveness of magnesium-rich olivine or forsterite in reducing the hydraulic conductivity of silt. Olivine is a naturally occurring nesosilicate mineral available abundantly in the earth’s subsurface. It is a sustainable and cost-effective additive that may be effective in stabilizing soil due to high amounts of magnesium oxide. Silt samples collected from two different lake beds were used in this study. Test results indicate that the hydraulic conductivity values for both the forsterite-treated silt samples satisfy the minimum requirement of hydraulic conductivity (≤ 1 × 10^–7 cm/s) as per the US Environmental Protection Agency (U.S EPA) guidelines. Hence, forsterite can be employed as an environmentally friendly additive that facilitates the use of dredged silt from the lake beds as a liner material.