Water pollution comes from a myriad of sources, both natural and from human activity. The most destructive causes of water pollution are man made, however. The largest sources include:
The burning of coal in power plants emits ash particulates that contain toxic metals like arsenic and lead. Coal and petroleum also contain sulfur compounds. Combustion generates sulfur dioxide, a toxic gas, and oxides of nitrogen. When emitted from exhaust stacks, these two compounds combine to form sulfuric acid in the atmosphere. When this toxic compound coalesces with water molecules, it falls to earth as “acid rain”. It contaminates land and bodies of water, and is one of the major causes of water pollution. Even though coal-fired plants have been mandated to install special chemical scrubbers to filter their emissions, a lot of pollutants still reach our environment. Despite what the pro-industrialists say, there is no such thing as “clean coal”.
Transportation vehicles (cars, trucks, planes, trains, etc.) burning petroleum distillates, gasoline, diesel, and various other fuels derived from petroleum, emit compounds of sulfur and nitrogen, and carbon oxides as well. Like coal burning, these compounds also contribute to smog and air pollution. They precipitate to earth and can make it into our drinking water sources. Basically anything that contributes to air pollution can also be causes of water pollution.
Mining operations of all kinds expose naturally occurring traces of heavy metals, sulfides, and radioactive materials. When exposed, or processed, these materials often end up in our waterways through runoff. In producing fertilizers for the agricultural industry, the phosphate mining industry generates fluorosilicic acid. It's a concentrated toxic waste that has radioactive components in it. Fluorosilicic acid is so toxic that it was listed on the Superfund list of compounds that pose the most significant risk to human health. It was once