International and European regulations permit the use of scrubbers to comply with the sulfur limits for marine fuel. Some scrubbers generate wastewater, which is discharged into the marine environment. The current environmental status of German coastal waters is moderate to poor. The contaminated wastewater adds a further stress factor for marine organisms in the North Sea and Baltic Sea as well as the adjacent catchment areas supporting shipping traffic. In principle, the use of clean liquid (diesel) and gas (⁠LNG⁠) fuels is preferable to an exhaust gas aftertreatment for the purpose of sulphur reduction. Based on legal and regulatory policy considerations, current knowledge indicates that imposing limitations of wastewater discharge generated by scrubbers is the best way to prevent the potential damage which results from their use.