EPA: Cruise Ship Discharges Exceed Standards

EPA recently released an assessment of cruise ship pollution in U.S. waters, which found that cruise ships routinely dump poorly treated sewage and highly contaminated raw gray water into harbors and coastal waters.

The assessment was a response to a lawsuit filed by the University of Washington Environmental Law Clinic on behalf of Friends of the Earth in May 2007. The group was seeking a response to a seven-year-old petition calling on EPA to analyze pollution from the rapidly expanding cruise ship fleet and find ways to prevent environmental harm. EPA provided detailed pollution data.

The federal agency found that cruise ship discharges contain concentrations of bacteria, chlorine, nutrients, metals and other pollutants that often exceed federal effluent and water quality standards and are harmful to human health and the marine environment. The report estimated that cruise ships produce an average of 21,000 gallons per day of sewage and 170,000 gallons per day of raw graywater that can contain as much bacteria as sewage. Large volumes of sewage sludge and oily water are routinely dumped overboard.

A majority of sewage samples taken by EPA from cruise ships equipped with Coast Guard-approved marine sanitation devices (Type II MSDs) violated national effluent limits for both ship and land-based sewage—and often exceeded national water quality criteria at point of discharge. EPA determined that treated sewage and raw gray water from cruise ships contain such high concentrations of bacteria such as fecal coliform, contaminants like chlorine, and nutrients including ammonia that the discharges can degrade water quality, threaten shellfish beds and contaminate beaches and swimming areas—even when diluted.

The report found that even the advanced wastewater treatment systems required in Alaska often do not meet national water quality standards at discharge for metals, chlorine or nutrients such as ammonia. EPA suggested that dilution might solve the problem but also incorporated an overview of equipment that could better remove contaminants.

EPA said that in 2006, 23 of 28 vessels operated in Alaska using the better systems. About 115 cruise ships operate in U. S. waters and more than 12 million passengers are expected to take a cruise next season. Ships are getting bigger, growing by about 90 feet every five years, EPA estimated.

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