When discharging oil from a tankship, what is done with the remaining oil after the main pumps have pumped out the tank's contents?

After the main pumps have pumped out the tank's contents, the remaining oil that cannot be removed efficiently by the pumps is typically stripped to one tank. This process ensures that as much oil as possible is recovered from the tank to minimize waste and environmental impact. The remaining oil, which is often referred to as "sludge" or "tank bottom," is then pumped out using the main pumps or dedicated stripping pumps, which are designed to extract the last traces of oil from the tank. This practice is crucial for ensuring compliance with environmental regulations and for maximizing cargo recovery.

Storing leftover oil in a separate tank or immediately discarding it would not be practical or sustainable, as it could lead to significant environmental hazards or loss of valuable resources. Mixing with water is also not a standard practice during this stage, as it complicates the recovery process and can introduce further environmental issues. The stripping process is therefore the most effective and responsible method for handling residual oil after discharging.