This standard deals with installations for the separation of light liquides (e.g. oil and petrol), i.e. those with a density up to 0.95 g/ cm3 from waste water by means of gravity and/ or coalescence. The standard is not primarily intended to apply to installations that are required to treat large quantities of trade effluent (e.g., oil refinery effluent). The standard may, however, still be appropriate for this purpose depending on local requirements.