23. Water Column Monitoring of Offshore Oil and Gas Activities on the Norwegian Continental Shelf: Past, Present and Future

As a result of aging offshore fields discharging higher volumes of produced water, and after the discharge of oil contaminated cuttings was terminated on the Norwegian Continental Shelf (NCS) in 1993, oil originating from produced water has become the dominant contributor of the Norwegian E&P industry to hydrocarbon and chemical input to the marine environment. To reflect the present situation, the environmental monitoring programmes have also changed. The Norwegian requirements related to offshore environmental monitoring are given in the HSE regulations for the petroleum activity. The water column monitoring consists of two parts: the condition monitoring and the effects monitoring. The programmes have developed through dialogue between the authorities, the scientific community, consultants, and the E&P industry, but will still be subjected to revision and improvement in the years to come.