ABSTRACTIn recent years, the practice of artificially recharging wastewater such as storm runoff, sewage effluent, and various industrial wastes into the subsurface has become of growing importance in Hawaii. In 1970 the Kahului Development Company began construction of a collection basin and four deep injection wells for the disposal of storm runoff from a residential development in Kahului, Maui. This presented a unique opportunity to evaluate the response of a basaltic Ghyben‐Herzberg aquifer to well injection, and to measure the rate of movement of injected water in the aquifer. The results of pumping and injection tests of one completed well and one test hole indicate that the finished injection wells should be able to transmit sediment‐free water at rates in excess of 5500 gallons per minute per well. Observation well measurements indicate that injected water moves at a gross velocity of one foot per minute in the basalt aquifer in the vicinity of the injection we