The World's Most Polluted River - The 200-mile long Citarum River in Indonesia, Jakarta hosts more than 500 factories along its banks and is quite possibly the most polluted river in the world. There is so much garbage coating the surface that in many places you can’t see the water, and it is more profitable to forage for garbage than making a living fishing the river, though you do risk catching a nasty disease by spending any time in it.