An oil-contaminated water drainage system is a system that serves the engine room and other areas where oil-contaminated materials are likely to leak. This system must be isolated from the main bilge water system. Typically, this is a low-power system that uses low-performance pumps with good suction parameters. The water pumped from the wells of this system enters bilge water bilge tank.
About 1% of all ship fuel consumption is waste. There are usually two types of oily waste on board: oily waste in the bilge (also known as oily water from the engine room) and oily sludge-type waste from fuel cleaning plants.
There are two ways to deal with this waste generated during the operation of a ship:

  • Store them on board in appropriate containers and deliver to port waste reception facilities.
  • Pump oily mixtures through the oily water filtration system into the marine environment.

NOTE: Oil-contaminated water filtration system is a special equipment designed to separate oil products and water, leaving up to 15ppm of oil particles, which must comply with international standards.
The ship should be provided with containers of sufficient size to allow the waste generated to be stored throughout the ship's voyage and pumped to reception facilities on shore. However, the water content of such oily mixtures is usually quite high, so its delivery to the port reception facility is often not financially viable. Therefore, to reduce the amount of oily water, it is pumped to the oily water storage tank in the bilge, where the oil is separated and begins to float on the surface of the water. This oil is pumped out and placed in a separate bilge oil storage tank and delivered to waste reception facilities in the port. The remaining water in the bilge oil storage tank is pumped into the oil water filtration system. The amount of oil discharged from the filtration system into the marine environment must not exceed 15 ppm. Thus, the filtration system must be fitted with a stopping device to ensure that emissions are automatically stopped when the oil content of the effluent exceeds 15 ppm. The oil remaining in this equipment also travels to a separate bilge oil storage tank. Part of this oil may be incinerated at the ship's fuel incineration plant and the remainder must be delivered to port reception facilities.

Example of engine room drainage

Last modified: Friday, 27 January 2023, 3:37 PM