Waste oily water is a by-product created by ocean going vessels which runs into millions of tonnes annually. A mixture of water, oily fluids, lubricants and greases accumulate in the lowest part of each vessel known as the bilges. The fluids come from a variety of sources including engines, piping and other mechanical and operational equipment required on board. Bilges are periodically pumped out to holding tanks which can be transferred to a facility on shore, or the contents can be processed with a separator on board and discharging clean water back to the ocean.
Discharge to the ocean is highly regulated, and the oil content of such water must be accurately monitored and remain within set limits. Bilge water monitors provide this data.