The screening of soil infested with invasive plant material can be a very useful tool in many site specific, invasive species, management plans. Where ground conditions are good, the screening of infested soil can reduce the volume of material requiring off-site disposal by up to 75%, delivering substantial savings in haulage and waste disposal costs. Similarly, in the case of on-site programmes, such as deep burial or permanent underground cell construction, the reduced volume of material to be buried can have considerable cost benefits. On restricted or difficult sites, the use of soil screening can make the difference between being able to implement a wholly on-site solution and having to revert to a much costlier off-site disposal programme.
For some brownfield and reclaimed sites, the ground conditions can be such, that the screening of the soil will not substantially reduce the volume of infested ground requiring disposal or burial. Sites may have been used previously to hold materials, such as mixed building rubble and debris, and non-hazardous industrial by-products. In such cases, engaging the soil screening technique may have an adverse effect on the biosecurity of the site, without any tangible benefit, and may not be an appropriate treatment option.
Where screening is to be used as part of an on-site, deep burial process, or in permanent underground cell construction, there should be a designated area provided within the site to accommodate the screened soil material. Ideally, this should be an area that will not be subject to future disturbance, for example, a location that will be incorporated into the overall landscaping layout. The area should be recorded and mapped, and the site should be monitored and inspected for a number of years to ensure that no risk material has succeeded in escaping or getting through the screening process.