Transport of Dissolved Chemical Contaminants in Ground-Water Systems*
Contaminants of various kinds frequently enter the ground-water system. The history of these contaminants after entering the saturated zone is important from the standpoint of pollution control. This history is determined by the manner in which the contaminants enter the system and by the physical and chemical characteristics of the system. The manner in which the contaminants enter the system determines one of the boundary conditions used to solve the differential transport equation. The physical and chemical characteristics of the system appear as parameters in the solutions of the transport equation. One-dimensional solutions are obtained for the important cases of radioactive contamination from (1) an underground nuclear explosion and (2) reactor waste disposal. These solutions can be applied to non-radioactive contamination by assuming an infinite half-life of the contaminate.
The solutions assume complex forms consisting of exponential and complementary error function terms. It is possible that some of these terms can be neglected without materially affecting the accuracy of the solution of a practical transport problem. However, before this can be done, methods must be developed for evaluation of the parameters describing the environmental physical and chemical conditions.