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This bad stuff must be coming from somewhere! Have you ever looked into a waterway, seen floating trash or debris, and asked yourself the question of where is this trash coming from? Your challenge is to take water samples from various locations in a port waterway and find out which ship or location is placing the dangerous substances into the water. Are you ready to air some ship’s dirty laundry? Then, shove off and sample.

Planning and Carrying Out Investigations

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What chemicals are commonly spilled into waterways?

Many different chemicals are spilled into waterways. Fertilizer and pesticides can run off of lawns or farmland into waterways. Heavy metals such as lead, aluminum, mercury, and arsenic can enter waterways from industrial sources or as parts of household chemicals that spill into the water. The chemical benzene is a common pollutant in waterways. Cargo ships that have damaged containers are also a possible source of leaking pollutants into waterways. Lastly, some personal watercraft owners, with or without thinking, dump toxic chemicals into the waters believing that "dilution is the solution." They have the mistaken notion that a small amount of a dangerous chemical placed in a larger body of water cannot harm the environment. This thinking is horribly wrong.

What is a pollutant point source?

Pollutants in water either come from a point source or a non-point source. A point source of pollution is where the pollution is directly introduced into the water. For example, a sewage pipe that empties directly into the water would be a point-source. A non-point source of pollution is an indirect source of pollution. An example of a non-point source is fertilizer that runs off of farmland into a waterway.

How is oil released into waterways?

Oil that leaks onto the road can be washed away into a waterway by rain. Oil can also be introduced into a waterway if an oil tanker spills. In addition, oil can enter waterways through ballasting practices used by oil tankers. The ballast is a tank at the bottom of a ship that is filled with liquid to help balance the ship and keep it afloat. Oil tankers often fill this with oil, and when they deliver the oil they empty the ballast and fill it with sea water. When the tanker is filled again, the sea water is ejected to be replaced with more oil. This sea water is contaminated with oil from the ballast, thus polluting the water with oil. Every year, humans release three to six tons of oil into the ocean.

What is benzene?

Benzene is a commonly used chemical that is a clear or yellow liquid at room temperature. Benzene occurs naturally as a product of forest fires and volcanoes, and is used by humans in crude oil, gasoline, and cigarettes. It is also used to make plastics, rubber, nylon, detergents and pesticides. Benzene interferes with a cell's ability to do its job. Benzene is a carcinogen, meaning that it can cause cancer. Symptoms of exposure to benzene include dizziness, drowsiness, confusion and rapid and irregular heartbeat.

What are heavy metals that are common pollutants in waterways?

Examples of heavy metals that are common pollutants in waterways are mercury, lead, cadmium and arsenic. Mercury is a product of coal burning and is found in acid rain. Lead is found in older paint and water from lead pipes will absorb some of the lead from the pipe walls. Both mercury and lead can affect the nervous system and kidneys. Lead can impair learning ability as well. Cadmium is found in sewage and can cause kidney disease. Arsenic is found in treated wood and can seep from wood through the ground into waterways. Arsenic may cause cancer and can damage the skin, eyes, and liver.

How does human waste get into waterways?

Believe it or not, sometimes human waste is pumped directly into waterways. In the Anacostia River in Washington D.C., billions of gallons of sewage are pumped directly into the river. Runoff from septic tanks can also pollute nearby waterways. Additionally, some owners of small watercraft purge the tanks of their toilets directly into waterways without doing any sewage treatment. Dock areas are particular problematic for having high bacteria level counts from raw sewage that has been released into the water.

Ship Location

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