Disposal of petroleum industry wastes containing natural occurring radioactive material (NORM) via subsurface injection is modeled using two different methods to estimate the potential radiological doses to individuals consuming water from a shallow aquifer. In the case study, it was assumed that the NORM was accidentally released into the drinking water due to casing failure during disposal. This study models the transport of radium in the aquifer to receptor points located at various distances from the injection well. Radionuclide concentrations at the receptor points were compared to drinking water standards recommended by the U. S. Environmental Protection Agency. The potential doses associated with subsurface injection of NORM were below drinking water standards even assuming a casing failure during disposal and the subsequent release of the entire volume of NORM wastes.
This paper compares a new analytical model for radial injection with a step-function source term with a simple mixing model and shows how these tools can be used to evaluate subsurface injection of NORM wastes.