Screening Tool for Using Waste Materials in Paving Projects

The properties of soft fine grained soils sometimes require enhancement to facilitate road construction and increase long term road durability. One option for roadbed stabilization is to treat the soil with fly ash, which possesses several beneficial engineering properties. However, the concentrations of elements in fly ash may potentially pose an unacceptable risk to human health. The Screening Tool provides straightforward assessments of this hazard. This tool is intended to be used as part of the assessment of due diligence of these risks. The Screening Tool does not give permission for the use of fly ash and the screening tool was not designed to predict the effects on surface waters, which are regulated by the Minnesota Department of Natural Resources (DNR) and Minnesota Pollution Control Agency (MPCA). This computer program provides guidance to users, but users must make sure the proposed project complies with all applicable and relevant rules and regulations that govern use of fly ash. Details of the calculation and further discussion of the importance of site-specific data is included in this document.