Water Pollution

Point Source PollutionPollution source can be specifically

identified

Non – Point Source Pollution

• As water from rainfall, snowmelt and irrigation flows across the surface of the land, it picks up contaminates from many different sources and deposits them into local lakes, rivers, streams, and wetlands

Runoff from roadways

Melting snow and ice carry surface contaminants into the watershed

Parking lots and marinas are non-point source pollutants

Farms and Landfills

Eutrophication

• The process in which a body of water develops high levels of nutrients such as nitrogen and phosphorus. (usually from sewage or fertilizer)– Nutrients cause an increase in the growth of

aquatic plants– Also cause an increase in amount of blue-green

algae– Algae forms surface mats which shade the lower

levels of plants from sunlight

• As bacteria and algae die, the decomposing bacteria multiply.

• The decomposing bacteria uses up all the ocean in the water

• Other, oxygen breathing, organisms also die

Cultural Eutrophication

•When the increased level of nutrients in the water is a result of human activities

Group Work• Construct Multi-flow maps for the following

water pollution events.• North Carolina Bay of Pigs pp 463-464• Outbreak in Milwaukee, Wisconsin pp 468 • Outbreak in Walkerton,Ohio pp 469• Medical Lake pp 469 –70• Eutrophication of the

Gulf of Mexicopp 472

Exxon Valdez pp 471 -474