There are many ways that our nations water is being polluted.
Scientists have specified eight general categories for the major kinds of polluntants. These categories include sediment, sewage and organic wastes, plant nutrients, infectious agents, organic chemicals, salts and mineral substances, radioactive substances, and thermal (heat) pollution. We need to do our best to help keep these and other polluntants out of our streams, rivers, and lakes. Sediment runoff is when the loose, rich top soil erodes, and is washed into rivers, streams and lakes. Much of the sediment runoff comes from poorly managed land in rural areas. A good portion of sediment run off also comes from unprotected areas in or near cities. The solution to preventing water pollution by sediment runoff is to control erosion.
Plant nutrients is another category of water pollution that creates special problems. There are three main plant nutrients that cause problems: nitrogen, phosphorus, and potassium. The plant nutrients are the main problem mostly because of the large amounts of them that into surface waters. Infectious Agents such as microorganisms and bacteriaare especially significant pollutants of water because they cause diseases. The solution to plant nutrient pollution as well as infectious agent pollution is to properly treat all sewage and waste.
Organic chemicals include a wide variety of materials that pollute water including pesticides andherbicides used to get rid of undesirable plants and insects. These chemicals get into the water by being washed into rivers, streams, and lakes, and are usually carried in the sediment runoff. It is vital that we do as much as possible to keep these chemicals out of our rivers, streams, and lakes by disposing of the harmful products properly.
Sewage and Organic Wastes are extremely significant pollutants because of the quantity involved. In addition to the wastes being carried from homes, large amounts of organic wastes result from food processing and industrial operations. Salts and Mineral Substancesare polluntants that can be very troublesome. As water moves across the land, it picks up natural salts and minerals. Salt in water is a major problem especially in irrigation. Mining waste has caused severe damage to some streams and rivers. There have been laws made to regulate mining which have helped to reduce the pollution of water from erosion and drainage of mines.
Thermal pollution is when the temperature of water is raised, like when water is used to heat or cool something. When water is heated and then put back into rivers, streams, and lakes, it causes a lot of problems for plants and animals that depend on that water. Plants and animals cannot survive for long when the temperature is much higher than normal. Some industries are using cooling towers and other things to help reduce the temperature of water they have used so that they can reuse it for cooling purposes.
These different kinds of polluntants are only a few of the many things that pollute water. You may have noticed that these pollutants are each related to the ways people use water. This means that if we are going to have clean, pure water we are all going to have to work together to see that our water is not damaged by the necessary ways we use it.