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Illegal Dumping

The US Coast Guard and Department of Justice use aerial surveillance to see illegal oil dumping by commercial ships

Photo Credit: US Department of Justice

An illegal “magic pipe” used to bypass a MARPOL oil pollution prevention equipment

Photo Credit: US Department of Justice

From aerial surveillance by governments around the world, we can see that illegal dumping by commercial ships is commonplace.

Five to fifteen percent of all large vessels are believed to break the law by discharging waste oil into the oceans.

The world’s shipping fleet is comprised of nearly 88,000 vessels. About 50,000 of these ships trade internationally.

It is believed that 85-90% of the world fleet complies with the law. Unfortunately, that means that the remainder, some 5,000-7,500 vessels, routinely and intentionally pollutes the seas.

Estimates of illegal dumping range from 70 million to 210 million gallons of waste oil spilled into the world’s waters each year.


Oil pollution is illegal, not to mention extremely harmful to the environment. So why do some ship owners and crewmembers still decide to pollute?

It comes down to money.

Modern cargo and container ships are amazing feats of industrial engineering. The machines that power them require oil-based fuels and lubricants to run smoothly, and oily leaks are commonplace.

Nearly all of the foul water and liquid waste on a ship drains into the bottom, an area known as the bilge tanks. Oil from leaky machinery also accumulates in the bilge.

Commercial ships often use a heavy fuel oil that produces an oily sludge when burned.

Oil tankers, in addition to accumulating regular operational waste, must also wash out their tanks between each trip, adding thousands of gallons of waste oil to the bilge tanks.

These sludge oil and bilge tanks must be emptied regularly.

Until the mid-twentieth century, it was general practice to simply pump sludge and oily bilge water into the sea.

However, as the environmental impact of oil pollution became clear, this practice was banned by the International Convention for the Prevention of Pollution of the Sea by Oil in 1954. These rules were strengthened in the 1970’s following the wreck of the Torrey Canyon in England by the creation of an international marine pollution treaty known as MARPOL.

MARPOL was designed to eliminate oil pollution in the seas.

It established that all ships must have functioning oil pollution control systems and keep a detailed and accurate oil record book.

It also requires that ships use an oily water separator to ensure that all waste water pumped overboard has an oil content of less than 15 parts per million.

Learn more about MARPOL and other Laws.

Oily hose found on polluting ship caught dumping oil overboard

Photo Credit: US Department of Justice


A 2002 report by the European Organization for Economic Cooperation and Development estimated that the average annual cost of meeting the MARPOL regulations runs from $30,000 a year for an average sized cargo ship to $55,000 for a large container vessel, and the cost can rise to $150,000 per year for a very large oil taker.

These costs represent, on average, between 3.5% and 6.5% of a ship's overall operating expenses.

Unfortunately, sometimes crewmembers or ship owners try to save money or the time it takes to unload waste oil in port by breaking the law.

Crewmembers may install a pipe or hose, known in the shipping industry as a “magic pipe,” to bypass the oily water separator and pump the polluted water directly into the ocean.

Alert! Intentionally dumping oily waste in the water is illegal and is actively prosecuted in the United States, resulting in large fines and jail sentences.

Crewmembers who blow the whistle on oil pollution crimes can often get awards of up to half the total fine. Read more about whistleblowers.

See a list of recent cases that show why the US Department of Justice has become renowned for its tough stance against oil pollution.

To learn about oil and the law click here.