Marine Discharge Glossary

Ballast Water: Water stored in tanks on a ship to provide stability. This water can be pumped on or off a ship.

Bilge Water: Water that collects in the lowest inner part of the ship's hull. Bilge water is frequently contaminated with oil and other lubricants from the engine room. Under various national and international standards, discharged bilge water must not exceed a certain maximum oil concentration (for example, 15 parts per million).

Black Water: Water contaminated with human waste, collected from shipboard toilets. Under various national and international standards, black water must be treated before being discharged from a vessel.

Discharge: In this context, any solid or liquid material that emanates from a vessel to a body of water, including anything spilled, leaked, poured, pumped, emitted or dumped from the vessel.

Doughnut Holes: A name given to several small areas of ocean within the Inside Passage that are more than three miles from the mainland and any islands. The federal Alaska cruise ship law "Title XIV--Certain Alaska Cruise Ship Operations" disallowed the discharge of raw sewage in the doughnut holes.

Gray Water: Used water from showers, sinks or basins, including used kitchen water.

Large Cruise Ship: Passenger vessels for hire that have accommodations for over 250 passengers.

MARPOL: Name given to the standards and requirements adopted by the International Convention for the Prevention of Pollution from Ships governing the discharge of oil and other hazardous substances, sewage and garbage.

Small Cruise Ship: Passenger vessels for hire that have 50 to 249 berths or other overnight accommodations for passengers.

Sewage: General term used to describe all liquid and solid waste material that is carried off in sewers or drains, including waste from toilets, sinks, showers, etc. Sewage may include both black water and gray water (see definitions).