Erosion and Sediment Control
Biotic Soil Technology for Efficient Landfill Closure - A Southeast US Case Study
A common issue encountered when attempting vegetative restoration for successful landfill closure is the lack of available quality topsoil to introduce a suitable environment for establishing sustainable vegetation. In most standard practices, topsoil is stripped and stockpiled until the another landfill cell reaches capacity and closure commences. When stockpiling topsoil, the amount of topsoil available for reuse is often lacking, as a result of the newly introduced terrain. The depth of topsoil that naturally and originally supported vegetation on the pre-landfill, horizontal footprint will now have a much greater surface area to cover as the typically flat terrain has expanded into substantial hills. Further, this topsoil that may have originally had properties indicative of healthy soil will have significantly degraded over the time period that the substrate is stockpiled and the time it will be utilized on cells are being prepared for closure. Another common practice is stripping and selling the topsoil for use on other construction projects. This often leads not only to added material and hauling costs when closing the landfill, but also issues with material consistency and quality from off-site sources.
In the absence of sufficient sources of quality topsoil, new technologies have been successfully implemented to treat and revive depleted soils to render them more capable of accelerating and sustaining vegetative growth. Essentially, on-site soils can often be “engineered” to improve their chemical and biological properties. Through prescriptively introducing materials to adjust soil imbalances and alleviate deficiencies, marginal soils become productive and sustainable vegetative cover is readily achieved.
Biotic Soil Technology (BST) is a generic term to describe the emerging field of manufactured growth media containing biodegradable fibers, biostimulants, biological inoculants and other components engineered to cost-effectively increase organic content, accelerate sustainable vegetative establishment and promote regeneration of denuded soils. The efficacy of BST is becoming more fully demonstrated with a growing portfolio of successful installations around the world on challenging sites involving civil construction as well as engineered cover systems for waste containment. Beyond the initial mission to cost-effectively foster more rapid and complete establishment of vegetation - yielding reductions in erosion and improved water quality, there is a need to monitor changes in organic matter levels, soil pH, microbial levels and other parameters that contribute to sustainable growing environments.
In this presentation we will review a local case study in the Southeastern US that outlines the site assessments required to determine the suitability and need for Biotic Soil Technologies, specifying appropriate materials and their sequencing, the execution of the plan and the outcome of the project.