[en] This report is the fifth in a series describing experiments conducted by the Colorado School of Mines for the Office of Crystalline Repository Development (OCRD) to determine the extent of blast damage in rock surrounding an underground opening. The report describes the instrumentation and method for testing permeability in crystalline rock masses. We applied the instruments in the CSM/OCRD test room in the Colorado School of Mines Experimental Mine (Edgar Mine) in Idaho Springs, Colorado. Even though this mine will not be a repository site, the equipment and methodology developed in this research program is applicable to other sites. The results presented in this report consider the variation of permeability measured with injection techniques. Preliminary results of core logging and deterministic fracture mapping program are briefly discussed. An attempt has also been made to relate the permeability variations to the stress field modification due to removal of the supporting rock mass