Leaky faults provide important flow paths for fluids to move underground. It is often necessary to characterize such faults in engineering projects such as deep well injection of waste liquids, underground natural gas storage, and radioactive waste isolation. To provide this characterization, analytical solutions are presented for groundwater flow through saturated aquifer-fault-aquifer systems assuming that both the aquifers and the fault are homogeneous and that the fault has an insignificant effect on aquifer hydraulic properties. Three different conditions are considered: (1) drawdown in the unpumped aquifer is negligibly small; (2) drawdown in the unpumped aquifer is significant, and the two aquifers have the same diffusivity; and (3) drawdown in the unpumped aquifer is significant, and the two aquifers have different diffusivities. Methods are presented to determine the fault transmissivity from pumping test data. , 1985]. Storing natural gas in aquifers is an effective way to accommodate the significant seasonal difference in natural gas consumption. More recently, constructing huge repositories in a low-permeability unsaturated zone in an arid region is thought to be a practical option for disposing of high-level radioactive waste. In all these
an estimated 423 million gal. (1.6 million m 3) of waste water were injected into 181 wells in the United States [U.S. Environmental Protection Agency