Why Waste it? Beneficial reuse of waste products
At SESL, we believe that waste materials, particularly soils and organic materials, have an intrinsic beneficial reuse value in our environment. Soils are are created at a rate between 1-10mm per year based on global estimates, so therefore the removal of 300mm or soil from a site is the equivalent of rewinding the clock between 30-300 years. We don’t have the time required to wait for new soils to be created, so we must protect and reuse what we have.
Some projects though do not have a supply of soil that can be readily available. Further, we rarely have soils that are immediately suitable for what we want to use them for, such as a developed landscape or the selected species. In these situations, we are forced to be more creative with how we identify and work with alternate sources of material.
SESL have been leading the charge in the scientific understanding of waste materials as a soil replacement. Recent project experience at Barangaroo Headland Park has taught us that we can take raw processed parent materials (i.e. sandstones) and create a viable soil growing media for the most sensitive of Australian native species. And it is not guess work. Through laboratory investigation in combination with our soil science expertise, SESL managed to formulate soil blends that are not just satisfactory, but create a vibrant and flourishing landscape.
It is also not just sandstone that we have had success with. By applying the same approach to other waste soils and overburden created by a project, SESL have been able to reduce landfill disposal costs, reduce the volume of materials imported to a project, and achieve the envisaged completed landscape at a fraction of the cost, while also achieving green star ratings for the project in the process. This has had proven success on the Pacific Highway upgrade in northern NSW and using tunnel spoil from inner city transport infrastructure projects.
Our work doesn’t stop with soils, and SESL develop reuse management strategies for a large variety of organic wastes, to facilitate the beneficial reuse back into the ecosystems where they were created. This closed loop, while reducing landfill waste, also aids in the viability of our productive soils. This is a story for another time.