Ocean Gets Raw Sewage Overload from Cruise Ships

Few things act as catnip for cable news producers more than some kind of unfolding sanitation and sickness disaster on board a cruise ship. Witness the ongoing coverage earlier this year as the Carnival Triumph limped under tow into Mobile, Ala., amid horror stories of the vessel being "caked in urine and raw sewage" to the extent that there was reportedly "sewage running down the walls."

All immensely unpleasant, to put it mildly. But while such catastrophes are fortunately few and far between, particularly given the huge number of trips that take place each year, the industry's critics have long focused on the impact of cruse ship sewage that ends up, not in passengers' cabins, but in the ocean.

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Writing in Outside earlier this year, Mary Catherine O'Connor noted that modern cruise ships are "floating mini-cities." She cites Ross Klein, an industry watchdog who maintains the Cruise Junkie website, as stating that a 3,000-passenger ship produces "over 450,000 gallons of gray water, 4,000 gallons of oily bilge water and as much as 19 tons of solid waste" every day, and that a ship's carbon footprint can be, per passenger, three times that of a Boeing 747.

While cruise ships operating are required to discharge only treated wastewater within three miles of the shore, beyond that limit, pretty much anything goes in terms of sewage discharge. According to Friends of the Earth (FoE), the Environmental Protection Agency estimates an average cruise ship with 3,000 passengers and crew produces 21,000 gallons of sewage daily - which, calculates FoE, is "enough to fill 10 backyard swimming pools in a week. That adds up to more than 1 billion gallons a year for the industry - a conservative estimate, since some new ships carry as many as 8,000 passengers and crew."

The organization notes that sewage pollution "can cause gastrointestinal diseases, diarrhea, hepatitis and other illnesses in people exposed through contaminated seafood or water. Fish, shellfish, coral reefs and other aquatic life can suffocate due to surplus nitrogen and phosphorous from ship sewage." And that's just the sewage: cruise ships also dump untreated "graywater" from showers, sinks and baths, which can contain many of the same pollutants.

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Fortunately, not all cruise companies are quite like the others, and some appear to be making good faith efforts to improve their practices. FoE's 2013 Cruise Ship Report Card, which has just been posted online, gives Disney Cruise Line an environmental grade of A, judged on three criteria: sewage treatment technology; whether ships can plug into shore-based power and if they use cleaner fuel than required by U.S. and international law; and compliance with water quality regulations unilaterally established by the State of Alaska to protect the coast of the Last Frontier.

Carnival Cruise Lines, on the other hand, received an F for sewage treatment and an overall C-, while Costa, Crystal, MSC and P&O Cruises all achieved a big fat overall F. Anyone concerned over the environmental impact of a cruise they may be considering can consult the card, not just to see how FoE grades different companies, but also to look at the rankings of individual ships.

In a statement provided to Discovery News, the Cruise Lines International Association (CLIA) called the FoE report "very misleading and distorted" and argued that "the cruise industry advocates best-in-class environmental stewardship practices that seek to fully protect the communities, ports and waters wherever we operate. CLIA member lines continue to invest extensively to implement a wide range of innovative environmental solutions that reduce air pollution and emissions, as well as treat sewage prior to discharge. Additionally, our industry in many areas employs practices and procedures that are substantially more protective of the environment than are required by regulation."

According to FoE's Marcie Keever, the progress shown by some cruise lines such as Disney is good news, but stricter government regulations are needed to push the industry as a whole into action.

"This is an industry worth billions of dollars that could install the most advanced sewage treatment technology available for the cost of a single can of Coke per passenger," said Keever. "We're encouraged that some cruise lines are taking incremental steps to improve their performance, but the entire industry must stop hiding behind weak regulations and take action to make sure the oceans remain as clean as in the photos in cruise brochures. But we also need the EPA to adopt tougher treatment standards to protect our oceans and coasts from the waste of these floating cities."

IMAGE: The Carnival Triumph cruise ship is towed towards the port of Mobile, Ala., Feb. 14, 2013. (Corbis)

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