Question

Beyond the Classroom-Field Trip
Visit a water body like a river, lake or large pond in your city. Observe the water and note the
pollutants you can see in the water. What human activities going on near the water body appear to
be polluting the water?
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Answer 1

Answer:

Water pollution (or aquatic pollution) is the contamination of water bodies, usually as a result of human activities, in such a manner that negatively affects its legitimate uses.[1]: 6  Water pollution reduces the ability of the body of water to provide the ecosystem services that it would otherwise provide. Water bodies include for example lakes, rivers, oceans, aquifers, reservoirs and groundwater. Water pollution results when contaminants are introduced into these water bodies. In addition to damage to many species, water pollution can also lead to water-borne diseases for people.[2] Water pollution traditionally is attributed to four sources, which provide the organization of this article:[3]

sewage

industry

agriculture

urban runoff including stormwater.

Raw sewage and industrial waste in the New River as it passes from Mexicali (Mexico) to Calexico, California

Water pollution can also be classified as surface water pollution (for example lakes, streams, estuaries, and parts of the ocean in marine pollution) or groundwater pollution. Sources of water pollution are either point sources or non-point sources. Point sources have one identifiable cause, such as a storm drain or a wastewater treatment plant. Non-point sources are more diffuse, such as agricultural runoff.[4] Pollution is the result of the cumulative effect over time. Supplying clean drinking water is an important ecosystem service provided by some freshwater systems, but approximately 785 million people in the world do not have access to clean drinking water because of pollution.[5