The Pacific Northwest National Laboratory (PNNL) is developing statistical methods for determining the amount of geophysical surveys conducted along transects (swaths) that are needed to achieve specified levels of confidence of finding target areas (TAs) of anomalous readings and possibly unexploded ordnance (UXO) at closed, transferring and transferred (CTT) Department of Defense (DoD) ranges and other sites. The statistical methods developed by PNNL have been coded into the UXO module of the Visual Sample Plan (VSP) software code that is being developed by PNNL with support from the DoD, the U.S. Department of Energy (DOE, and the U.S. Environmental Protection Agency (EPA). (The VSP software and VSP User’s Guide (Hassig et al, 2002) may be downloaded from http://dqo.pnl.gov/vsp.) This report describes and documents the statistical methods developed and the calculations and verification testing that have been conducted to verify that VSP’s implementation of these methods is correct and accurate.