Utilisation of Mine Wastes in Plant Based Alternative Cover Trials

Evapotranspiration (ET) landfill covers have been proposed as an alternative to traditional barrier covers, with aims to improve long-term environmental performance. Trial of these systems is underway in south-east Australia utilizing mine waste for the cover substrate and a selection of native vegetation. Preliminary planting trials have seen the successful establishment of vegetation on the material, while compaction trials have enabled in situ dry bulk density to be related to the method of placement. The designed ET cover profiles will be assessed with four full scale test sections, including two lysimeters for the direct collection of percolation and two sections open to the normal fluxes of landfill gas, heat and water vapour present in the landfill environment in order to observe their effects on the establishing vegetation cover.Full Tex

A sustainable approach for hydraulic control of landfills using mine waste and native plants

Evapotranspiration (ET) landfill covers have been proposed as an alternative to traditional barrier covers, with aims to improve long-term environmental performance and reduce the financial burden of closure costs, particularly for rural landfills. This research is exploring the potential for an ET cover to be implemented at a landfill in south-east Australia. Opportunities exist at this site to utilize a basalt quarry waste product (scalps) typical of the extractive industry for purposes of the cover substrate, while vegetation selection has focused on local plant species. Although the agronomic properties of the scalps are not ideal, preliminary planting trials have shown that the scalps substrate has significant 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 scalps to be related to the in situ dry bulk density achieved. Performance of the designed ET cover profile will be monitored with four large test sections. Two of the test sections will employ lysimetry for the direct collection of percolation, whilst the other two sections will remain open to the normal fluxes of landfill gas, heat and water vapour present in the landfill environment in order to observe their effects on the establishing vegetation coverNo Full Tex

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

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.No Full Tex

Phytocapping as a cost-effective and sustainable cover option for waste disposal sites in developing countries

Few waste disposal sites in developing countries are designed and operated as engineered sanitary landfills due to common technical and financial constraints. Phytocapping presents a natural soil-plant alternative to the conventional engineered landfill cover design. It requires less engineering input and has a lower cost than conventional impermeable covers as it only utilizes local recourses. It also offers the advantage of oxidating methane to reduce landfill greenhouse emissions. This type of covers has the potential to make a significant difference in the way that developing countries are capping their waste sites. This paper introduces the phytocap concept as well as discusses its relevance and advantages for developing countries.Full Tex

Phytocapping of landfills

Phytocapping presents a sustainable alternative to the conventional top barrier cover design. It relies on the capacity of a porous substrate (usually of locally available soil) to store water together with the natural processes of surface evaporation and plant transpiration to remove the stored water as a means of controlling water ingress into the landfill. This chapter is based on the Australian experience in researching and implementing phytocaps as final covers for municipal waste landfills. In 2006, the Australian Alternative Cover Assessment Program (A-ACAP) was established to compare the performance (in terms of drainage, landfill gas, and plant growth) of phytocapping against traditional compacted clay barrier caps. The trials showed that phytocapping has the potential to reduce drainage as effectively as compacted clay barrier caps and in a more predictable manner; to oxidize fugitive methane emissions more effectively than barrier caps; and to enable more variable and sustainable vegetation communities to be established. Guidelines published as an outcome of the A-ACAP have been adopted in Australia as a basis for design and are being referenced in regulatory guidance as they are reviewed and updated. Phytocapping has now been approved and constructed in all mainland States (with the exception of Western Australia, where construction is due to commence shortly). The full-scale experience has shown that phytocapping is an alternative to conventional barrier caps but requires specialized input into design and different techniques for construction and maintenance to ensure its continued performance