Bilge water treatment is an environmental technology, and as such must meet the strict requirements of international laws. Any discharge of untreated bilge water into the ocean is prohibited, and carries stiff financial penalties, especially in protected areas. The MARPOL regulation that is currently in force allows discharge into international waters only up to a residual oil content of 15 ppm. Some national, regional, or local regulators require even lower levels of residual oil.

Resolution MEPC.107(49) from the IMO (International Maritime Organization) defines the performance requirements for bilge water treatment systems on ships. Filtration Group separation technology also conforms to the European MED (Marine Equipment Directive) 2002/75/EC. Many manufacturers of bilge water oil separators have met the requirements for approval under the various regulations, but a majority of their systems actually fail to meet the required separation refinement in practice.