🔍 Key Concepts

• Engine room drain systems (clean vs contaminated) • Typical sources connected to a contaminated drain tank • Environmental rules about overboard discharge of oily mixtures

💭 Think About

• Which system would collect liquids that CANNOT legally be pumped directly overboard without treatment? • What types of drains in machinery spaces are normally routed to the oily water separator or sludge handling system? • Among the options, which type of contamination is most tightly controlled and monitored on ships?

✅ Before You Answer

• Identify which drains in machinery spaces go to a bilge/contaminated drain versus those that can go overboard • Recall MARPOL/USCG focus on oily mixtures and their discharge limits • Confirm which kind of contamination requires special treatment equipment (e.g., oily water separator), not just simple discharge