Methods of soil improvement that consider both the physical/mechanical properties and the environmental/geochemical aspects of soils have been studied and developed in recent years. This is due to the necessity of a nonhazardous soil improvement method that can alleviate the environmental concerns of current soil improvement methods. Several considerations such as the use of biological organisms and biopolymers have been researched for their applicability in soil improvement. In this study the use of casein proteins derived from bovine milk is purposed as a possible soil improvement material. With its biological origin and characteristics, casein treated soil is regarded to be harmless and safe to the environment. Additionally, with the large and growing amount of dairy wastes, this soil improvement method could serve as a possible sink for such wastes. Results of casein treatment have shown that a definite increase in strength is observed when casein based binders are integrated into the soil.