This technical memorandum was prepared to summarize results of drilling, construction, equipping, and testing at hydrologic test wells DHRES-03, DHRES-04, and DHRES-05/DHRES-05B. The wells were installed to characterize hydrogeologic conditions in the Gila Conglomerate and Apache Leaf Tuff west of the Concentrator Fault in the vicinity of West Plant site and to provide monitoring locations for the aquifer west of the Concentrator Fault during dewatering operations in 2010 and 2011. Groundwater level data obtained from DHRES-03, DHRES-04, and DHRES-05/DHRES-05B has been incorporated into the RCM hydrologic monitoring program.