In 1998, the Norwegian government issued White Paper Number 58, followed by the "Zero Discharge Report" that requires the oil industry operating in the Norwegian sector of the North Sea to develop a strategy for reaching zero environmentally harmful discharges of produced water (PW) by 2005. A management tool that uses environmental risk and hazard assessment has been developed to identify the most potentially environmentally harmful discharges of PW and to quantify the environmental benefit of different actions to reduce these discharges. The Norwegian Oil Industry Assn. working group for PW developed the environmental-impact factor (EIF) that compares the potential benefit of measures to reduce PW discharges and forms a basis for a cost-effective total approach to PW management.