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Key Oil Pollution Laws

An Oily Water Separator is required by MARPOL /><p class=Photo Credit: Common Good Productions

Alert! Fifteen parts of oil per million of water is an invisible amount of oil in water. Any release of oily waste that produces a visible sheen is illegal.

Oil pollution is prohibited under both international and US federal law.

International Treaty: MARPOL

The international treaty governing marine pollution is known as the MARPOL Convention. MARPOL was written in 1973 (and revised in 1978) by the International Maritime Organization (IMO), an agency of the United Nations responsible for the safety and security of shipping and the prevention of marine pollution by ships.

MARPOL has six sections, each addressing a different kind of pollution. The first section, Annex I, deals with oil pollution.

In addition to setting standards for oil tanker construction, this section establishes three key laws relating to commercial ships and oil:

1. All ships weighing more than 400 gross tons must maintain an accurate oil record book to document the movement and fate of all oil brought on board.

2. No waste oil or oily water can be discharged into the sea unless the ship is en route and the mixture is passed through an Oily Water Separator that reduces the oil content to less than fifteen parts per million of water.

3. All discharges of oily water within 50 miles of shore are prohibited.

One hundred and thirty-six countries, including the United States, have signed the MARPOL convention. This covers 98% of the world’s shipping tonnage, and every signatory is required to enact domestic laws to implement the convention and enforce compliance. In the United States, the legislation implementing MARPOL is known as the Act to Prevent Pollution from Ships.

Learn more about MARPOL

Key U.S. Laws



The Act to Prevent Pollution from Ships (APPS) was passed by Congress in 1980. APPS is the US law that implements MARPOL. It makes it a crime to knowingly violate the oil pollution provisions of MARPOL.

The APPS regulations governing oil pollution can be found at Title 33, Code of Federal Regulations, part 151. Read regulations


1. APPS/MARPOL requires that oily wastewater on ships be processed by a properly working oily water separator and oil  content monitor and that any discharge contain no more than 15 parts per million of oil.

2. APPS/MARPOL requires that all discharges be accurately recorded in an oil record book.


The operation of large marine vessels generates large quantities of oily sludge and oily waste. Engine departments produce oil-contaminated bilge waste when water mixes in the bottom of the vessel, known as the bilges, with oil that has leaked from machinery, engines, lubrication, or fuel systems.

These oily mixtures should be collected, stored, and processed to separate the water from the oil using a pollution prevention control device known as an Oily Water Separator and an oil-sensing device known as an Oil Content Monitor.

After passing through the Oily Water Separator, bilge waste containing fifteen parts per million or less of oil (as measured by the Oil Content Monitor) may be discharged overboard. When properly installed and used, a sensor that detects oil content in concentrations greater than 15 parts per million sounds an audible alarm and automatically shuts down any overboard discharge.


Oil Record Book used as evidence in an oil pollution crime case

Photo Credit: Common Good Productions

Ships are required by APPS and MARPOL to maintain an Oil Record Book. The disposal of oil residue and oily mixtures, slops from bilges, and oily bilge water should be recorded here. Full and accurate notes must be kept about the discharge of this material overboard, by incineration, or through other forms of disposal without delay by the person in charge of the operations. The oil record book must also keep records of any emergency, accidental, or other exceptional discharges of oil or mixtures, including a statement of the circumstances of, and reasons for, the discharge. This book must be available for inspection at all times.

WHO IT COVERS: APPS covers almost all US-flagged and foreign commercial ships in US navigable waters. For US-flagged ships, APPS also covers their actions in waters around the world.

PENALTIES FOR INDIVIDUALS: Violating APPS is a class D felony. Individuals can receive a fine of up to $200,000 per count or up to twice the gross gain or loss from the offense. Individuals can also be imprisoned for up to six years.

PENALTIES FOR CORPORATIONS: Corporations that violate APPS can face fines of up to $500,000 per count or up to twice the gross gain or loss from the offense.

WHISTLEBLOWER PROVISION: People who provide information about violations to APPS that leads to a conviction can receive up to half of the fine. In recent years, awards have ranged from $40,000 to more than $400,000.

Whistleblower provision -- [33 U.S.C, Section 1908 (A)]

Alert! Maintaining a false oil record book and lying to U.S. Coast Guard officials is one of the most common charges brought against polluting ships. Lying to a Coast Guard officer, presenting a falsified oil record book, hiding evidence, or telling seafarers not to tell the truth can be all be felony offenses and can lead to heavy fines and imprisonment.

Alert! Under the Clean Water Act/OPA 90, a “harmful quantity” of oil is any amount that causes a film or sheen to appear on the surface of the water or causes sludge to be deposited beneath the surface.


BACKGROUND: The Clean Water Act was passed in 1972 to protect fish and wildlife by ensuring water quality. One section addresses oil pollution and bans any discharge of oil into the navigable waters of the U.S. or any waters that affect natural resources in the U.S. exclusive economic zone in harmful quantities.

The Clean Water Act was amended by the Oil Pollution Act of 1990 following the devastation of the Exxon Valdez oil spill in Alaska.


1. It is a crime to negligently or knowingly discharge a “harmful quantity” of oil into US waters.

2. Failing to report an oil spill to the government is also a crime. Any “person in charge” on a vessel that has discharged oil must immediately report the spill to the National Response Center.

PENALTIES FOR INDIVIDUALS: Up to $200,000 per incident and up to five years in prison.

A negligent violation of the Clean Water Act is a misdemeanor and can result in up to one year in prison.

A knowing failure to report a spill or a leak is a felony and can result in up to 5 years in prison.

PENALTIES FOR CORPORATIONS: Corporations in violation of the Ports and Waterways Safety Act can be fined up to a million dollars.


The Ports and Waterways Safety Act is mostly concerned with ensuring safety aboard vessels in US waters. It is a crime for “a person in charge” to fail to report a hazardous condition onboard a ship to the Coast Guard.

“Hazardous condition” is defined in this act as “any condition that may adversely affect the safety of any vessel, bridge, structure, or shore area or the environmental quality of any port, harbor, or navigable waterway of the United States.”

Failing to report a hazardous condition is a felony.

Penalties: For individuals, up $200,000 per incident and up to five years in prison

For corporations, up to a million dollars