Lime sludge, an inert material mostly composed of calcium carbonate, is the result of softening hard water before distribution as drinking water. In the previous two parts of this series of articles, laboratory- and full-scale experiments verified the feasibility of using lime sludge as a substitute for limestone and for fill material that is stabilized for embankment construction. Further laboratory testing provided detailed geotechnical data to assist engineers in designing embankments using stabilized lime sludge. In this part, a scaled model embankment was constructed and tested, and the results are presented and discussed herein. In addition, the costs of using lime sludge as a fill material for Department of Transportation and municipal water and wastewater projects are discussed in relation to recent documented fill costs that did not use lime sludge. Using stabilized lime sludge fill below the frost line in deep embankments is a viable method to dispose of the large stockpiles of lime sludge in Iowa and may provide water customers with cost savings in lime-sludge disposal.