Water Cycle The oceans contain 97 percent of the water on earth. That leaves 3 percent of water as fresh water, and of that, only 2 percent is available for our use. Because our water supply and Pollution is so small, it is important to protect our water. Sadly, humans have impacted that small bit of water through pollution. Let's look at some of the major causes of water pollution. Clouds with sulfuric acid Acid Rain The chemicals present in smoke pollution from sources such as factories, power plants and vehicles are transported with water vapor. This polluted water vapor follows the water cycle, eventually falling back down to earth as precipitation and is known as acid rain. After this polluted water is on earth's surface, where else can the water cycle transport it? Factory Pollution Acid rain harms aquatic life. Acid Mine Drainage Precipitation Infiltration WASTE ROCK Seepage OLD MINE WORKINGS O2 Acid Mine Drainage (AMD) is one Pennsylvania's worst pollutants. Most AMD comes from abandoned coal mines. Acidic water is formed when sulfur from minerals meets ground water. This polluted ground water reaches the surface through seepage. AMD can be easy to see. Sediments can be red, orange or yellow. ACIDIC WATER HEAVY METAL LOADED WATER DEAD FISH This stream has been affected by Acid Mine Drainage.