Scale-dependent dispersion is a phenomenon that manifests as an increase in the magnitude of the dispersion parameters with the distance of travel, or the time after the spill. This implies that contaminant plumes occupy a larger portion of the aquifer at later times than that predicted by the traditional convection-dispersion models. Although it is an area of active research, scale-dependent ground water pollution modeling is now available through the practical application of a new hydrologic theory of dispersion, The KYSPILL software was developed as an application of this theory, KYSPILL provides an easy way to simulate and graph the movement of contaminant plumes in heterogeneous soils and aquifers, It has self-supported menus and windows that allow the selection of the type of spill, the input of hydrogeologic data, and the plotting of contours and breakthrough curves. It simulates biological or radioactive decay, adsorption, point or nonpoint sources in the unsaturated zone and subsequently in the saturated zone. An automatic self-diagnosis system tests every input data, and an on-line, context-sensitive, help system aids the user in the input data and running phases, KYSPILL is a simple tool for those chemical spills with little or uncertain data. It may be used for preliminary forecasting, monitoring planning, or remedial actions.