Cruise Ships & Sewage — FOE Misses the Point

ship-islandHere is yet another case of the media taking a wildly inaccurate sets of claims about ships at face value.  The news media has been touting a new study by the environmental group Friends of the Earth. The title of the FOE press release of December 4th makes their claim quite clear — Cruise ships flushed more than a billion gallons of sewage into oceans again this year.  And who is FOE? Their website claims that “Friends of the Earth is a bold and fearless voice for justice and the planet.”  They may be “bold and fearless,” but do they have the first clue about ships?  Or are their claims just so much, err… sewage?

To be fair, the cruise lines do have an uneven record, at best, related to waste handling. Fifteen years ago, Royal Caribbean paid an $18 million fine for illegally dumping tons of waste oil and chemicals into US waters. In 2003, Carnival Cruise Line paid a $200,000 fine for violating California’s ballast water law.  Toward the other end of the spectrum, in 2013, Princess Cruise Lines paid $20,000 for dumping water from a swimming pool into Glacier Bay.  So while the cruise lines may not have always followed the rules in the past, the regulators are doing a somewhat better job at enforcing the rules overall. Could the cruise lines really be dumping all that sewage?

The FOE press release’s title give it away. They claim that “cruise ships flushed more than a billion gallons of sewage into oceans again this year” Is that possible?  The answer is no.  The billion gallons referenced is FOE’s estimate of the total sewage generated on all cruise ships in one year. To claim that all the raw sewage produced was then dumped into the ocean is a wild exaggeration at best. Calling it a boldfaced lie might be a more accurate characterization.

Ships are not allowed to simply “flush sewage into the oceans” to use FOE’s terminology.  From Annex IV of the International Convention for the Prevention of Pollution from Ships, known universally as MARPOL. the general rules are:

“The discharge of sewage into the sea is prohibited, except when the ship has in operation an approved sewage treatment plant or when the ship is discharging comminuted and disinfected sewage using an approved system at a distance of more than three nautical miles from the nearest land. Sewage which is not comminuted or disinfected has to be discharged at a distance of more than 12 nautical miles from the nearest land.”

Why 12 miles? Again from MAROL Annex IV: “It is generally considered that on the high seas, the oceans are capable of assimilating and dealing with raw sewage through natural bacterial action. Therefore, the regulations in Annex IV of MARPOL prohibit the discharge of sewage into the sea within a specified distance of the nearest land, unless they have in operation an approved sewage treatment plant.”  Even when more than 12 miles from shore, there are rules for the amount and manner in which raw sewage may be dumped. As many, if not most, cruise ships spend much of their time within 12 miles of shore, they all have and use approved sewage treatment plants.

In addition to MARPOL requirements, states set their own standards.  Some, like Alaska, require a higher standard of sewage treatment than is required internationally. Many states also set No Discharge Zones where, as the name implies, no discharge of even treated sewage is allowed.

FOE also goes on claiming that most cruise ships use outdated 35 year old technology for sewage treatment. What is this claim based on? On their ‘Cruise Ship Report Card‘ they make this strange claim: “Cruise ships can use traditional Marine Sanitation Devices (known as Type II MSDs). Although cruise ships can legally use 35-year-old MSD technology to treat sewage, the U.S. EPA has found that sewage treated with this older technology often contains significant amounts of fecal bacteria, heavy metals, and nutrients in excess of federal water quality standards..

This assertion is very odd. The EPA and the US Coast Guard jointly administer the standards for Type II MSDs.  Only EPA and USCG approved Type II MSDs can be installed on boats and ships. How then is it likely that the EPA would determine that the MSDs it approved, do not meet its standards?  Fro reference, Type II MSDs are designed to meet the EPA standards for surface water discharged from a shorebased sewage treatment plant.

FOE prefers Advanced Wastewater Treatment Systems, (AWTS) sewage treatment, which is indeed superior to Type II MSDs.  It is the sewage treatment system required of all ships which cruise to Alaska. The reason that many modern cruise ships have AWTS installed is to allow their operators the flexibility to move the ships between Alaska and the Caribbean or Europe.

Ultimately, FOE gives too much away when it expresses it preference in shipboard sanitation. In their ‘Cruise Ship Report Card’ they write: “The last and most environmentally protective method is for cruise ships to hold treated sewage onboard and not dump near our sensitive coasts and marine protected areas.

So if FOE prefers that cruise ship retain sewage in holding tanks, where will the sewage ultimately go?  It will have to be pumped ashore to be processed in shorebased treatment plants. And this is where FOE misses the point.

When cruise ships are tied up to a pier in New York or Miami and it starts to rain, there is a very good chance that raw untreated sewage will start flowing int the waters of either harbor.  But it won’t be coming from the cruise ships.  The sewage will be flowing directly from the city sewers.  The title of a Newsweek report from last summer, summarizes it perfectly — If It’s Raining, NYC’s Raw Sewage Is Probably Pouring Into the Waterways.  New York, like many cities, has a combined sewage and rain water system. In heavy rains, the system overflows and carries sewage into the harbor.

Miami, a major cruise ship port, has similar problems. Just this April, Miami-Dade County and state and federal regulators entered into a consent decree to begin a multi-year $1.6 billion repair to the very leaky sewage system.

It is not just New York and Miami with sewer problems. According to the EPA there are over 770 cities in the United States where sewage flows untreated into the waterways when it rains or snows heavily.  And what is the effect of these sewage overflows? Last summer over 1 in 10 US beaches was unsafe for swimming due to seawage contamination.  As reported by USA Today: The EPA estimated that up to 3.5 million people become ill from contact with raw sewage in swimming water each year.

Could this sewage contamination be from cruise ships?  It is possible, but not likely. Many of the worst regions are not frequented by cruise ships. USA Today notesRegionally, the Great Lakes showed the highest level of polluted beaches, followed by the Gulf Coast, New England and the West Coast. The regions with the lowest level of pollution were the Delmarva (Delaware, Maryland and Virginia) region, the Southeast and the New York-New Jersey region. Of all the states, Ohio was the individual state with the highest rate of failure in its beaches – with seven beaches on the “repeat offender” list.

So no, cruise ships do not dump 1 billion gallons of untreated sewage into the oceans as FOE would have you believe.  Rather than obsessing over cruise ships, which follow international, federal and local standards for sewage treatment, perhaps FOE should focus on the the tons of sewage from more than 700 cities that flow into our waterways whenever it rains or snows.

Thanks to Irwin Bryan for contributing to this post.


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5 Responses to Cruise Ships & Sewage — FOE Misses the Point

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  2. Doug Bostrom says:

    Well, we can’t vanish nitrogen.

    FOE does a poor job of explaining themselves, but their point “…hold treated sewage onboard and not dump near our sensitive coasts and marine protected areas.” is defensible in the sense that treated sewage while microbiologically benign from the perspective of infection can still be seriously disruptive to an ecosystem adjusted to function without loads of what is at root fertilizer in the water.

    A little less hysteria and a little more science in these press releases would be welcome. Every word wasted on histrionics is one that can’t be used to convey facts.

  3. Rick Spilman says:

    Maybe I am missing something here. What I do not understand about the suggestion that sending sewage ashore is a better choice, is that the sewage will then be treated and sent back into the waterways, usually from a point discharge, where the nitrogen concentrations will be even higher. In that respect sewage treated on a moving ship at least has the advantage of a wider dispersal of the nitrogen-rich organic matter.

    I also find the harping on Type II MSDs as 35 year old technology to be dishonest, as while the Type II MSDs can be certified back to around 1973, the technology has been improving on the newer shipboard units.

  4. Pat Byrnes says:

    So, what do the cruise lines * actually * do?
    Do they hold it until 12 miles offshore and then dump it all?
    Do they pump it for treatment ashore?
    Do most of the ships have treatment plants approved for 3 mile discharge? What is the reality on board?

  5. Rick Spilman says:

    I suspect there is not one answer. It is probably highly dependent on the ship and the deployment. A ship that shuttles between New York and Bermuda might dump at sea and treat the sewage in New York. In Bermuda the ships pump the sewage ashore where it is pumped by the Bermuda authorities, untreated, out to sea. Ships deployed in Alaska use AWTS systems while the international standard, Type II treatment plants seem to be more common in the Caribbean.