Ground water flow on the Oak Ridge Reservation (ORR) is dominated by permeable fractures within the relatively impermeable rocks. It is possible to detect the fractures which intersect a borehole using conventional logging tools (electrical, sonic, acoustic televiewer, caliper, temperature), but not with any certainty which of these fractures are permeable and are part of a connected network. This poses a problem for the groundwater modeler. Should all known fractures be included in the model Only major fracture
