What measures can be taken to prevent water pollution?
In developing countries, improvement in sanitation to reduce sewage contamination of drinking water is the most important way to control water pollution. Even in developed countries like the United States, there is room for improvement in municipal sewage treatment. In many U.S. cities, heavy rains can overwhelm storm sewers so storm water becomes contaminated with sewage from wastewater sewers. The most effective way to control the majority of water pollution, however, is to control runoff and the contaminants it picks up. For example, contour plowing and cover crops can reduce runoff from agricultural land, and cutting down on the use of pesticides and fertilizers can reduce pollution of runoff when it does occur. Creation and protection of wetlands can also help control water pollution, because wetlands filter pollutants from runoff before it enters bodies of water.