When produced water from offshore production is discharged to sea, it contains some oil (aliphatic and aromatic components), production chemicals and NORM (Naturally Occurring Radioactive Substances). These groups of substances are traditionally treated in different ways in the regulations and standards.Regulations of oil in produced water are mainly related to max concentrations and the total discharge of the aliphatic (dispersed) fraction. Regulation of chemicals is based on the environmental risk profile of each production chemical, although efforts are made towards regulations based on risk assessment of the discharge of the mixture of substances. For discharge of NORM dissolved in the produced water, no limit values are imposed. For NORM solids (scale, sludge, sand) from process equipment, discharge to sea is in general not allowed -it is re-injected or taken to a deposit onshore.

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