For many years, the European Union has been promoting the development of inland, rail and intermodal transport with the aim of reducing road transport, which has a negative impact on the environment. It was assumed that river transport should be a priority in the transport system of the European union community. The European Parliament, introducing the regulation (EU) 2016/1628 in 2016, established a new emission standard for machines not running on the road (NRMM) - the Stage V standard. This standard defines the emission limits of carbon oxides (CO), hydrocarbons (HC), oxides nitrogen (NOx) and particulate matter (PM) which from 1 January 2021 will apply to all newly built units. Ecoexhaust solutions based on DPF and SCR technology are able to meet these requirements. Since units operating in inland waters often face the problem of the amount of available space in machinery rooms, we know how much importance should be paid to the optimization of the structure so as to use the available space in the most effective way.