This report presents the risk assessment methodology used to estimate the incremental increase in individual lifetime risk from the use of cement kiln dust (CKD) as an agricultural soil amendment. It includes the documentation and results of a central tendency and high-end deterministic risk analysis and a quantitative uncertainty analysis using commercially available Monte Carlo simulation software. RTI conducted this risk assessment in accordance with the U.S. Environmental Protection Agency (EPA) human health risk assessment guidance (U.S. EPA, 1991, 1988, and 1989). The risk estimates used for regulatory decisionmaking have been developed using a deterministic method, which produces point estimates of risk based upon single values for input parameters. The deterministic results in this analysis have been estimated using a double high-end risk assessment methodology. In this method, the input parameters are varied between the central tendency (50th percentile) value and the high-end (95th percentile) value one at a time and then in pairs of any two independent variables to produce a series of point risk estimates. The point estimate in which all variables are set at central tendency is assumed to be the central tendency risk estimate, and the highest risk estimate for any combination of double high-end variables is assumed to be the high-end estimate (approximately 95th percentile) of risk.