Cruise ships have been described as "floating cities" and like cities, they have a lot of pollution problems. Their per capita pollution is actually worse than a city of the same population, due to weak pollution control laws, lax enforcement, and the difficulty of detecting illegal discharges at sea. Cruise ships impact coastal waters in several US states, including Alaska, California, Florida, and Hawaii.
All cruise ships generate the following types of waste:
A 3,000-passenger cruise ship (considered an average size, some carry 5,000 or more passengers) generates the following amounts of waste on a typical one-week voyage:
In addition, these ships take in large quantities of ballast water, which is seawater pumped into the hulls of ships to ensure stability. This water is typically taken in at one port and then discharged at the ship's destination, which can introduce invasive species and serious diseases into U.S. waters. A typical release of ballast water amounts to 1,000 metric tons.
Cruise ships (and other ships) are required to have "marine sanitation devices", which are designed to prevent the discharge of untreated sewage. Sewage must be treated to specified standards before discharge if the ship is stationary of if it is within a specified distance (generally three miles) of shore. When the ship is beyond three miles from shore, there are no restrictions on the release of untreated sewage.
There are no restrictions on the release of gray water, except in the Great Lakes.
Discharge of oil or oily water into US navigable waters, adjoining shorelines or waters which may affect natural resources within 200 miles of shore is prohibited, unless the oily water is passed through an oil-water separator designed to reduce the oil concentration to 15 parts per million (ppm) within 12 miles of shore or within 100 ppm beyond 12 miles from shore. Ships are required to keep Oil Record Books to record their disposal of oily residues and bilge water.
Hazardous wastes should be properly packaged and labeled and disposed in permitted on-shore facilities, but the applicability of the Resource Conservation and Recovery Act (RCRA) to ships and Cruise Lines is not clear.
The dumping of garbage at sea is prohibited within certain distances from shore, generally ranging from 3 to 25 miles. Dumping of plastic is prohibited everywhere at sea, and all discharge or incineration of garbage must be recorded in a Garbage Record Book.
Although there are pending new rules from the EPA on diesel engine emissions, there are essentially no present emission restrictions and the proposed new rules are still much weaker than for land-based emission sources.
The cruise ship industry does not have a good record of compliance with the existing weak regulations.
Pollution from cruise ships is totally preventable. The technology exists. We simply need effective regulations that are enforced.
The Bluewater Network (now Friends of the Earth) issued a report on Cruise Ship Pollution in March 2000 that urged the EPA to conduct an in-depth review of the impact of waste discharges from cruise ships, examine the existing applicable regulations, develop recommendations on how to better control cruise ship waste discharges, and ensure that the regulations were implemented. Surfrider joins Friends of the Earth, The Ocean Conservancy, and other environmental groups in urging EPA to respond to the March 2000 request to identify and regulate pollution from cruise ships.
In California, a protest by The Ocean Conservancy and other environmental groups resulted in an agreement by Princess Cruises not to discharge wastewater while located in the Monterey Bay National Marine Sanctuary. More recently, it was announced in August 2010 that new federal regulations, scheduled to go into effect in 2011, would bar cruise vessels and large commercial ships from discharging sewage within three miles of California's coastline. On February 9, 2012, EPA finalized a rule in response to an application from the State of California, and established a No Discharge Zone (NDZ) for large vessels in all California marine waters that will go into effect in March 2012. More info.
In Maine, a bill was introduced in March 2003 which would make Maine one of the first states to establish statewide wastewater quality standards for passenger ships by prohibiting ships from dumping any partially treated sewage or other wastewater in or around Portland Harbor.
On an individual level, if you are planning a cruise, investigate the cruise line to be sure their ships do not have a record of pollution (see Cruise Ship Report Card). If you are on a cruise ship and observe any dumping of plastic or hazardous materials to sea, you should report it to the National Response Center at 1-800-424-8802.
Every year Friends of the Earth releases a Cruise Ship Report Card that gives an A through F grade to 15 cruise lines. The cruise lines are graded on sewage treatment, air pollution reduction, water quality compliance, and overall environmental footprint. Here is their 2014 report card and an article from Discovery News about that.
Getting a Grip on Cruise Ship Pollution (Friends of the Earth)
2014 Cruise Ship Report Card (Friends of the Earth)
Cruise Ship Pollution Overview (Oceana)
More Cruise Ship Information (Oceana)
U.S. Keeps Wary Eye on Cruise Ships for More Pollution, by Marilyn Adams, USA TODAY. November 8, 2002.