The discovery of contamination of the potable groundwater supply on the island of Oahu aroused public concern in the early 1980s. Pesticides used in growing pineapple and pipeline spills of aviation fuels caused several essential wells to be taken out of service. Federal and state officials took immediate action to meet the crisis and developed long-term strategies to address public health concerns. The state legislature mandated closer reporting on the sale and distribution of pesticides and took other steps to strengthen the authority of state environmental officials. From this experience, the authors outline several measures other water utilities can take to forecast or meet similar contingencies. Includes 19 references, tables, figure.