Redefining Acceptable Hydrocarbon Levels in Water Discharge
The UK has a long, arguable successful, history of industrial pollution control, particularly within its chemical sector – with it’s first real pollution control authority being the Alkali Inspectorate dating back to 1906. As the offshore industry developed, the Prevention of Pollution Act of 1971 came about to prohibit the discharge of any oil or oil waters into the sea, although exemptions are granted which allow produced water discharges to contain up to 40 ppm oil-in-water, on average. It is understood that this limit was derived on the basis that process equipment then available could achieve this and that below this value no visible oil sheen could be seen on the water surface. With an increasing public awareness of environmental issues, it is appropriate for the relevant authorities and industry prepresentatives to reconsider the limits on hydrocarbon levels in oilfield water discharges, and various factors related to this are presented in this paper.