- When on a cruise ship, you may notice little difference between the ship's restroom facilities and the ones in your own home. The toilet flushes. The sink and shower faucets pour out water that disappears down the drain. But what happens to the waste once it is flushed down the toilet, and to the water that disappears down the sink and shower drains? The answer to these questions is the dirty secret the cruise industry doesn't like to advertise.
- There are two types of sewage on a cruise ship:
1) Gray water, which is water that goes down sink and shower drains; and
2) Black water, which is the waste that flushes down the toilet.
Gray water drains to a tank called (logically enough) the gray water tank. Black water drains to a tank called the black water tank. Both are large, central tanks hidden from the passengers' view, and into which all of the restroom facilities drain.
Gray and black water tanks fill up quickly on a cruise ship. To handle the large amounts of waste, the cruise ship must empty the tanks. Ideally, tanks are treated before dumping to minimize contaminants--either with chlorine or an environmentally friendly bacteria solution. After treatment, the tanks are emptied into the ocean. There you have the cruise-ship industry's dirty secret: Cruise ships regularly dump human waste into the ocean! - Just like the plumbing in your home, the plumbing on cruise ships can get clogged. If waste gets stuck in the pipes before it reaches the gray or black water tank, it can cause a blockage. If a blockage occurs, a plumber must be called to clear it. In 2006, passengers aboard the Thomson's Destiny cruise ship were stuck without working toilets for 3 days due to blockages in the plumbing.
- According to Oceana (an organization whose mission is to protect the world's oceans}, the cruise-ship industry dumps 255,000 gallons of gray water and 30,000 gallons of black water into the ocean every day. The United States allows cruise ships to dump untreated sewage into the water as long as the ship is 3 miles away from shore. If the cruise ship treats the sewage, the 3-mile restriction does not count, and the sewage can be dumped anywhere. Alaska is the only place within United States waters that does not allow dumping. Even sewage and gray water treated with chlorine or environmentally friendly bacteria are often highly contaminated. It is hard to effectively treat such large amounts of sewage and wastewater in a short time. Bacterial solutions are made up of bacteria that are designed to destroy more harmful bacteria. The process is lengthy and cannot be performed in a short period of time. In addition, chlorine is harmful to aquatic life.
Oceana is urging the Environmental Protection Agency to set and enforce better regulations to stop cruise-ship pollution in the oceans.
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