The Environmental Impact Factor - a proposed tool for produced water impact reduction, management and regulation

Abstract

Abstract The Norwegian government issued in 1998 White Paper No. 58 followed by the "Zero discharge report" requiring the oil industry operating in the Norwegian sector of the North Sea to develop a strategy for reaching "zero environmental harmful discharges" of produced water (PW) within 2005. As a result Miljøsok proposed to develop a management tool based on environmental risk and hazard assessment to identify the most potential environmentally harmful discharges of PW, and to quantify the environmental benefit of different actions to reduce these. The Norwegian Oil Industry Association (OLF) working group for PW was asked to develop the Environmental Impact Factor (EIF), and the tool has so far been applied for PW management on a single platform level. The plan is to elevate this work to a regional scale in order to compare the potential benefit of measures to reduce PW discharges in the whole area, and to form a basis for a cost-effective total approach to PW management. The EIF is based on a combined environmental risk and hazard assessment of PW discharges, accounting for both composition and amount of the discharge. The EIF is also linked to the environmental impact assessment (EIA) studies in the area and the environmental monitoring programme for the water column, initiated in 1999. Determination of the EIF for a single platform allows the operator to rank the available technologies for PW discharge reduction on a cost-benefit basis. The EIF identifies the source of potential environmental damage and quantifies the benefit of any action taken to reduce this. Technologies like PW re-injection, treatment and removal or replacement of process chemicals can thus be ranked based on cost and environmental benefit.