Summary: There are between 0.8 to 1.2 million leaking underground storage tanks (USTs) mostly storing petroleum by-products such as gasoline and fuel oil. Leaking petroleum products from USTs contaminate soil and move to contaminate ground water. In 1984 US Congress added Subtitle I to the Resource Conservation and Recovery Act to regulate leaking USTs. Now almost all the fifty states require removal and proper disposal of petroleum contaminated soils (PCSs) to prevent further contamination of groundwater. Excavated PCSs are disposed in Landfills, used for bioremediation and low temperature description, and disposed in highway industry as construction materials. The cost/benefit, engineering, and environmental aspects of disposal of PCS in highway industry as a construction material is discussed in this paper.