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Water Supply on Cruise Ship..How do they do it?


Trnkk
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Has anyone ever wondered about water supply on the cruise ship? With thousands of people using water every day, and also restaurants, spa, pool... Where does the water come from? Will it ever be out? How do they refill the water, where and when? I kept this question in my mind ever since I came back from our first cruise in Feb' 08. We are cruising again in Feb' 09 I am going to ask them (captain) this time but I think I ask you guys here on CC may be someone has already asked this question and would like to share this information so I can get it out of my head beforehand. Am I nuts?

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http://www.westbasin.org/WaterResources/OceanWaterDesalination/AboutDesalination/tabid/106/Default.aspx

 

Ocean-water desalination creates a safe and reliable water supply that is local and not dependent on varying weather conditions or water rights. Ocean-water desalination is the process of removing salt, other minerals and impurities from ocean water so that it can be used to supplement the existing water supply.

Desalination is a time-tested process that originated in the Middle East, dating back to Julius Caesar around 49 BCE. There are more than 21,000 desalination plants in the world today. Saudi Arabia produces more than 70% of its drinking water from desalinated ocean-water and Australia is using desalinated ocean-water to supplement the water supply for some of its cities.

The United States’ first known experience with desalination was in 1791 when Thomas Jefferson had a simple distillation process printed on the backs of all papers distributed on ships, giving sailors an option to produce drinking water in case of emergency.

The first desalination plant built in the U.S. occurred in the 1960’s at Guantanamo Bay, Cuba. When water supplies to the naval base were cut off in retaliation for the Cuban Missile Crisis, the base became self-sufficient, desalinating 3.4 million gallons of water every day.

 

 

Today, cruise ships and submarines desalinate ocean-water to meet the needs of their passengers, but less than 1% of the U.S. population on land currently receives desalinated water to drink. Ocean-water desalination has been in practice in the U.S. for hundreds of years, though, and as the technology continues to improve, it is becoming easier and more affordable to produce desalinated ocean-water for everyday human uses.

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Good to know! I have wondered about that. I've also wondered what they do with all the waste... food, toilets, etc. Not trying to sound gross, but...

 

Waste food gets pulverized and thrown overboard.

 

Sewer waste gets filtered, treated, and dumped overboard.

 

There's nothing gross about it, it's all biodegradeable and gets eaten by the fish and plants.

Edited by gtalum
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Good to know! I have wondered about that. I've also wondered what they do with all the waste... food, toilets, etc. Not trying to sound gross, but...

 

 

No different than a motor home. Waste goes into Grey water holding tanks or BLACK water holding tanks. Showers etc, to grey water. "Terlets" to black water. Some ships dehydrate the waste and compress it.

 

Dan

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The water on a modern cruise is produced using sea water, heat (from the engines cooling system or hot engine exhaust gases), and a wonderful piece of technology called an evaporator.

 

This takes the heated sea water, (heated to over 80C, 180F), and pumps it into a chamber which is at lower than atmospheric pressure. The water boils, and the steam is collected as very pure water. The now cooler slightly saltier sea water is then pumped into another chamber which is at lower pressure, again it boils, the steam is collected, and so on. The pure water is then treated to make it taste nice (distalled water tastes horrible!), and to ensure it's safe to store and drink.

 

The stored drinking water is continuously tested, and several times a day samples are taken and kept.

 

A large ship such as the Zuiderdam or Queen Victoria can produce well over a thousand tons of fresh water per day.

 

VP

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You probably don't want to know about the waste: (taken from oceana.org)

 

Sewage

The average cruise ship with 3,000 passengers and crew generates about 30,000 gallons of human waste and 255,000 gallons of non-sewage gray water every day. Cruise ships are allowed to release treated sewage almost anywhere they sail. They are also permitted to release untreated

gray water—non-sewage wastewater from galleys, dishwashers, baths, sinks, showers, and laundries—anywhere they sail, except Alaska. Cruise ships can also lawfully release untreated sewage, or black water, anywhere beyond three miles from the shore (except in certain areas of Alaska). Cruise ships are required to have onboard waste treatment systems, known as

marine sanitation devices (MSDs), the industry is required to keep logbooks of their discharges, but are not required to monitor the quality of the waters into which they routinely dump their waste.

 

Solid Waste

The average cruise ship produces seven tons of garbage and solid waste every day.

Under Annex V of the International Convention for the Prevention of Pollution from Ships, or MARPOL 73/78, (implemented by the federal Act to Prevent Pollution from Ships, Marine Plastic Pollution Research and Control Act and

their regulations), cruise ships are barred from dumping plastics anywhere

at sea and floatable garbage within 25 miles of shore. They are permitted, however, to dump garbage that has been ground into pieces smaller than one inch when they are three miles from shore, and unground garbage when they are at least 12 miles from shore.

 

Toxics

The average cruise ship with 3,000 passengers and crew generates 15 gallons of toxic chemicals every day.

Toxic chemicals generated by cruise ships are generally waste products from photo developing, dry cleaning, painting and other activities. Under the Resource Conservation and Recovery Act, ships are required to store these wastes onboard while under way, and then, once in port, to transfer them to

certified chemical treatment and disposal facilities. Since this information is not made available to the public there’s no way to ensure that each ship is complying with this requirement.

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Some fresh water is bought in ports. Ever notice the 2 1/2" blue hose on stilts (those little X things) hooked up to the ship.

 

You beat me to it! :)

 

While ships produce alot of fresh potable water via desalination, they also take on potable water in their home port. While modern ships have the capacity to produce sufficient supplies of potable water the desalination process requires alot of energy. Fresh water taken on in port is less expensive.

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Some fresh water is bought in ports. Ever notice the 2 1/2" blue hose on stilts (those little X things) hooked up to the ship.

 

Just to be clear, its not primarily being bought in the for-future-use sense, its mostly that while they are in port they cant run the desalination plant (it requires the engine to be on), so they run off the port's water supply instead. Some of it ends up stored in tanks and used eventually, sure, but its not like this is anything like the main supply for your trip.

Edited by lanoitarus
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  • 5 years later...

I stumbled on this old thread link after doing research on the effects of sodium levels that are still present in cruise ship desalinated water.

 

We have been cruising for over 30-years, taking long and shorter cruises - i.e. 4-nights to 120-night world cruises and up to approx 10-years ago health problems associated with water used on board had not been a problem. It now seems that more and more salt is being absorbed into our bodies via a number of means, which have resulted in swollen legs and ankles etc. and possible heart failure

 

The probable means we assess to be, in descending order:

1) Desalinated water being given to us in copious quantities at dinner.

2) Ever increasing amount of salt being added to food

3) Breakfast/Lunch or casual fruit juice consumption (powdered or concentrated.

4) Heavily salted Ocean air whilst on deck or balcony.

5) Showering/bathing & cleaning teeth

 

In 2012 we were unfortunate in that we had a nasty bout of Gastroenteritis whilst on the NCL Star which led to us being seriously dehidrated, resulting in the doctor putting us both on saline drips. To rehidrate us further we were told to drink gallons of water, which was brought to our cabin in jugs (presumably desalinated water). On arrival back home, after spending five unplanned nights in a hotel to rest up, my wife was very weak and visited our doctor. He ordered a full blood count test which resulted in an emergency situation as she was deemed to be close to the minimum that would support life.

 

It took 6-months for her system to stabilise and her levels are now thankfully normal. During our last cruise in June 2013 we had a complimentary drinks package which included bottled water, so at the dinner table we instructed the assistant waiter not to fill our glasses up with desalinated water, getting a large bottle of spring water instead.

 

Call it a coincidence if you like - all I know is that neither of us experienced swollen legs or ankles !

 

Other comments on this thread have said that they have never heard of any problems with a ships water supply - WE HAVE.

 

Also in 2012, we were sailing on the MSC Opera from Beonos Aires, Argentina to Southampton, UK and had a suite. Those of you that have been in an Opera suite will know that what MSC deem as a suite is little more than a long standard balcony cabin, however, being disabled I wanted extra space.

 

A couple of days out of BA we noticed that whenever we put our soap in the hand basin full of water (desalinated) it turned blue immediately. It should be noted that for the previous three months the ship had been doing a series of 3-night fun cruises from BA to Montevideo and back, whereby most of the passengers were first-time cruisers.

 

As our cruise was for 21-nights, there was no way that we were going to put up with blue faces etc. - the past occupants having either accepted the situation, couldn't be bothered or thought that was normal ! On speaking to the cabin steward he said that his own washing water did the same thing and a woman in another suite had complained that her hair turned blue when she washed it. We told him that we wanted to see an engineer as we suspected that the water supply was contaminated.

 

An odd-job man arrived and said that this was normal and had happened in various sections of the ship for months. On telephoning the customer relations desk I reported that I wanted to see the First Engineer. Long and short is that a senior engineer came to our cabin and saw for himself that something was wrong. Our steward was asked why he had not reported it himself and he said that he had done so, but nothing had happened. He, and other stewards were afraid of losing their jobs if they questioned matters further.

 

The desalination plant was checked and a personal appology was sent to us from the captain. It appears that one of the sections of the plant was found to have a blocked filter system, causing too much chemicals to be added to the water. Had we filled a kettle with that over-chemicalised water we could have been ill. So there you have it - desalinated water can be lethal if not overseen properly.

 

During my Internet research of "Effects of Desalinated water" I descovered that way back in the 1970's a USSR controlled study found that desalinated water could be harmful if the water had high levels of sodium (not all can be filtered out), calcium or Boron are in it, which may cause liver/kidney failure and brain damage. The report said that only reports written in English have ever been used to assess the danger - this report was translated from Russian and written during the Cold War!

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After the water is processed, trace minerals are usually be added back into the water. One of these is sodium. Morton Salt is one of the leading companies making water treatment products. Unfortunately there is no way to know how much sodium is in the water you are drinking.

Once I switched to drinking primarily bottled water we bring onboard, I no longer experienced swollen feet and fingers.(And I have not changed my eating habits onboard.)

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To the OP. If you get a chance on your next cruise, sign up for the "behind the fun" tour. I think you would appreciate it. They will give you a 3-4 tour of the ship including the control room where your can see the panels that control all functions of the ship (including secondary navigation). You can ask questions of the officers on duty and they can show you via monitors exactly what the systems are doing.

 

The tour sells out fast and runs around $100 pp on larger ships but is well worth it if you're the kind of person that wants to see the goings on of ship function. It also includes the galley, laundry, theater, crews areas, and bridge tour with a picture of you with the captain. We did it on the Freedom in July and it was a very interesting tour.

Edited by rolaur
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In 2012 we were unfortunate in that we had a nasty bout of Gastroenteritis whilst on the NCL Star which led to us being seriously dehydrated, resulting in the doctor putting us both on saline drips. To rehydrate us further we were told to drink gallons of water, which was brought to our cabin in jugs (presumably desalinated water). On arrival back home, after spending five unplanned nights in a hotel to rest up, my wife was very weak and visited our doctor. He ordered a full blood count test which resulted in an emergency situation as she was deemed to be close to the minimum that would support life.

 

Considering how much you have cruised, I would consider that perhaps there was another cause for your dehydrated state other than the water on board. If it was the water, why did it take so long for the situation to occur with all the cruising you have done? I'll bet there was some bug going around that was the main cause.

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Cruise lines get drinking water from two places. They will sometimes buy potable water in port (you can sometimes see the large hose running to the ship on the pier), test the water, further filter and treat it and then use it as drinking water. Most modern cruise ships can also make enough drinking water to meet all their needs, but this does take a lot of electricity which does have a cost in the fuel used to make the extra power. The two basic processes involve flash evaporation and reverse osmosis. From what we understand (from a ship's environmental officer) the water produced is essentially pure distilled water with only a trace amount of salt (probably less then you get in bottled or tap water at home). In fact, the water is so pure and tasteless that the ship actually adds back a formula of minerals to give it some flavor (try drinking distilled water and you will understand why they need to add some flavor). As to the salt issue (many of us have had swollen ankles on ships) most of it comes from the food served onboard. Professional chefs add salt to nearly everything (just watch the Food Network sometime) to improve the flavor.

 

Hank

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We sail a LOT on Carnival's Fantasy out of Charleston, SC. (A 4 1/2 hour drive!) The ship fills up with their water and we can't stand it. Someone from Charleston told us once why their water is awful but don't remember why. Anyway, we bought a water filter from Lowes - under $20- and put it on our bathroom sink. Now our water tastes fine!

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Considering how much you have cruised, I would consider that perhaps there was another cause for your dehydrated state other than the water on board. If it was the water, why did it take so long for the situation to occur with all the cruising you have done? I'll bet there was some bug going around that was the main cause.

 

Sorry - you have misunderstood my comments - In NO WAY was I suggesting that the water we drank had anything to do with the Nirovirus we contracted. We figure that the bug either infected us after eating a salad in Belize or it was brought on ship by one or more of the children. The point I meant was that we were rehydrated by the ships drinking water which therafter caused secondary problems.

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Good to know! I have wondered about that. I've also wondered what they do with all the waste... food, toilets, etc. Not trying to sound gross, but...

It depends on what ship. For example, we know what happens to human waste on the Carnival Triumph. :eek:

(Sorry -- Couldn't resist.)

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Okay, a few misconceptions and misrepresented facts here, so I as a Chief Engineer of 38 years standing will weigh in on this topic:

 

1. Most water onboard is produced from sea water. This is done in two ways; distillation and reverse osmosis. Distillation is done as one previous poster eloquently spelled out. It is pure distilled water. Reverse osmosis presses water molecules through a porous membrane at high pressure, with the pores of the membrane sized to only allow water molecules, or smaller to pass through. Both sodium and chlorine ions in the sea water are too big to pass. This water will have some minerals in it, but usually not sodium as many cruisers submit when complaining about water retention, since the pore size is too small. Both types of watermakers can only be operated when outside 12 miles from shore. The evaporator uses the heat from the cooling water (think your car's radiator) of the engines, so the ship needs to be running several generators (like at sea) to run the evaporators. Reverse osmosis units are strictly electrical, but again, you are not allowed to take in sea water for de-salinization while in port.

 

2. Some water is taken while in port, not necessarily the "home port". This happens when the itinerary is port intensive, so the ship cannot operate the watermakers enough time to make up for the port time.

 

3. All water, whether produced onboard, or taken from port, is treated with chlorine to kill bacteria, before it is placed in the ship's tanks. The water that is circulated through the ship's piping is constantly being monitored and treated with chlorine to maintain the required USPH residual chlorine level. This is why many say the water tastes funny. Chlorine is also an agent of water retention in humans.

 

4. The drinking water dispensers, soda guns at the bars, and ice makers all have carbon filters attached to remove the chlorine (it causes problems with the internals of the machinery), so many swear by only drinking the water in the buffet, and this is why.

 

5. A ship of 2200 passengers and 900 crew will use about 800-1000 metric tons (200,000-260,000 gallons) per day.

 

6. Some water is also reclaimed from the A/C units (if you've got one at your house, you know about the condensate pump to take away the water). Depending on the itinerary and time of year, this can be 100-200 metric tons per day. This water is generally used in the ship's laundry.

 

7. Food waste is ground to the consistency of oatmeal, and is pumped overboard at night. This can amount to 10 cubic meters of food waste.

 

8. Most cruise ships these days have what is called an "Advanced Waste Water Treatment" system. This system takes ALL of the water used onboard: gray water from sinks and showers, galley water from sinks and dishwashers, laundry water, black water from toilets, and processes it before sending it over the side when at sea. These plants can treat water to nearly pure drinking water status. They are tested every other month for whether they meet the requirements for coliform bacteria that they are sending over the side. It is better than 90% of municipal systems. There is one engineer whose sole duty is to operate and maintain the waste water treatment system. These systems will handle the full amount of water used onboard (800-1000 metric tons/day on the ship I referenced above), in a constant treatment flow, and when in port, the water is stored in tanks for discharge at sea.

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After the water is processed, trace minerals are usually be added back into the water. One of these is sodium. Morton Salt is one of the leading companies making water treatment products. Unfortunately there is no way to know how much sodium is in the water you are drinking.

Once I switched to drinking primarily bottled water we bring onboard, I no longer experienced swollen feet and fingers.(And I have not changed my eating habits onboard.)

 

You are thinking of the types of water softeners used in homes. Generally, the only thing added back to distilled water is to neutralize the slightly acidic nature of distilled water. This acidity can erode copper piping on the ship, and leach minerals from your body if consumed over long periods. The mineral most commonly used is CALCIUM carbonate, which has no sodium in it at all. As I've stated in many posts here, chlorine in the ship's water is probably one culprit in water retention, not sodium.

 

And, if you are that interested, you can get a sodium testing device for water, for about $20. Just dunk it in a glass of water and it will tell you how many grains of sea salt per milliliter there are. Then check your tap water at home.

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You probably don't want to know about the waste: (taken from oceana.org)

 

Sewage

The average cruise ship with 3,000 passengers and crew generates about 30,000 gallons of human waste and 255,000 gallons of non-sewage gray water every day. Cruise ships are allowed to release treated sewage almost anywhere they sail. They are also permitted to release untreated

gray water—non-sewage wastewater from galleys, dishwashers, baths, sinks, showers, and laundries—anywhere they sail, except Alaska. Cruise ships can also lawfully release untreated sewage, or black water, anywhere beyond three miles from the shore (except in certain areas of Alaska). Cruise ships are required to have onboard waste treatment systems, known as

marine sanitation devices (MSDs), the industry is required to keep logbooks of their discharges, but are not required to monitor the quality of the waters into which they routinely dump their waste.You are correct in the letter of the law, but most cruise lines have adopted Advanced Waste Water Treatment systems, which treat all water, black and gray to near purity before discharging. With an AWWTS, NCL ships have been granted permission to discharge the effluent from the treatment system WHILE AT THE DOCK IN ALASKA, where the most stringent waste water regulations exist.

 

Solid Waste

The average cruise ship produces seven tons of garbage and solid waste every day.

Under Annex V of the International Convention for the Prevention of Pollution from Ships, or MARPOL 73/78, (implemented by the federal Act to Prevent Pollution from Ships, Marine Plastic Pollution Research and Control Act and

their regulations), cruise ships are barred from dumping plastics anywhere

at sea and floatable garbage within 25 miles of shore. They are permitted, however, to dump garbage that has been ground into pieces smaller than one inch when they are three miles from shore, and unground garbage when they are at least 12 miles from shore.From my experience, they generate much more than 7 metric tons/day. Again, you are quoting the letter of the MARPOL regulations, while most cruise companies have learned that there are way too many camera phones out there, and way too many people who know that turning in a tip about potential pollution can result in a large reward. Therefore, very few cruise ships discharge anything other than ground FOOD waste overboard. Nearly everything else is compacted (plastic and metal), ground (glass and china), or baled (cardboard) for disposal ashore. Most paper, and cardboard is incinerated while at sea, and the ash is baled for disposal ashore. Cooking oil is frequently landed for "bio-diesel" refiners to collect.

 

Toxics

The average cruise ship with 3,000 passengers and crew generates 15 gallons of toxic chemicals every day.

Toxic chemicals generated by cruise ships are generally waste products from photo developing, dry cleaning, painting and other activities. Under the Resource Conservation and Recovery Act, ships are required to store these wastes onboard while under way, and then, once in port, to transfer them to

certified chemical treatment and disposal facilities. Since this information is not made available to the public there’s no way to ensure that each ship is complying with this requirement.

While the information is not available to the public, it is monitored by the USPH/CDC and the USCG as part of its port state control function of monitoring MARPOL requirements. It is also monitored by the classification society that underwrites the ship's seaworthiness, and the International Safety Management system, required by the IMO. There is an Environmental Officer onboard whose sole duty is to deal with the waste stream, ensure it is properly segregated, documented, and landed ashore.
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This water will have some minerals in it, but usually not sodium as many cruisers submit when complaining about water retention, since the pore size is too small.

 

Thank you. I always suspected there was a scientific reason to take those dubious claims with a "grain of salt". :D

Edited by boogs
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