Investigators at the University of Notre Dame's Center for Bioengineering and Pollution Control have conducted research and development studies since 1980 in the broad area of hazardous waste management. These efforts have been primarily directed at the use of periodic processes. Many of the findings have been applied to the construction and operation of full scale bioreclamation facilities. Early research and development activities were directed at the suspended growth, Sequencing Batch Reactor (SBR). The SBR is an activated sludge-like, periodic process that has been used effectively for the treatment of both domestic and industrial wastewaters (Irvine and Busch, 1979; and Irvine and Ketchum, 1989). Due to the time-oriented nature of the SBR, simple operational modifications have allowed for nutrient removal (Alleman and Irvine, 1980a; Alleman and Irvine, 1980b; Ketchum et. al., 1987; Irvine et. al., 1979; Manning and Irvine, 1985; and Palis and Irvine, 1985) and the control of bulking sludge (Brenner et. al., 1992; Chiesa and Irvine, 1985; Chiesa et. al., 1985; and Dennis and Irvine, 1979). The SBR has been shown to be a cost effective and energy efficient means of removing hazardous organic compounds found in industrial wastes and leachates from landfills (Brenner et. al., 1992; Herzbrun et. al., 1985; Irvine et. al., 1984; Irvine and Wilderer, 1988; Smith and Wilderer, 1987; and; Ying et. al., 1987). The Soil Slurry-Sequencing Batch Reactor (SS-SBR) described by Irvine et. al., (1993) and the Sequencing Batch Biofilm Reactor (SBBR), a fixed film periodic system that can be used in conjunction with granular activated carbon (Chozick and Irvine, 1991), were developed in the late 1980's and early 1990's. Recent efforts have been directed at periodically operated in situ bioremediation systems. This paper provides a brief overview of how such systems can be used to bioremediate contaminated leachates and soils.