A Sustainable Approach for Hydraulic Control of Landfills Using Quarry Scalpings and Native Plants

Abstract

Phytocovers have been proposed as an alternative to traditional barrier covers, with aims to improve long-term environmental performance and reduce the fi nancial burden of closure costs, particularly for rural landfi lls. This research is exploring the potential for a phytocover to be implemented at a landfi ll in southeast Australia. Opportunities exist at this site to use basalt quarry scalpings typical of the Victorian extractive industry for purposes of the cover substrate, while vegetation selection has focused on indigenous plant species. Although the agronomic properties of the scalpings are not ideal, preliminary planting trials have shown that the scalpings have signifi cant potential for sustaining a careful selection of native trees and grasses. The application of mulch has not resulted in any overall plant growth advantage. A compaction trial conducted with full-scale machinery has enabled the method of placing the scalpings to be related to the in-situ dry bulk density achieved. Performance of the designed phytocover profi le will be monitored with four large test sections. Two of the test sections will employ lysimetry for the direct collection of percolation, while the other two sections will remain open to the normal fl uxes of landfi ll gas, heat and water vapour present in the landfi ll environment in order to observe their effects on the establishing vegetation cover.