This post is an extract from EMSA’s publication “Addressing Illegal Discharges in the Marine Environment” focusing on the various ways oily waste are being produced onboard vessels. The volume of oily waste generated and/or stored on board a vessel depends on various factors. These include, for example type, age and size of vessel; type and age of equipment related to oil separation and storage; maintenance of vessel and equipment and external factors such as availability of Port Reception Facilities.