In the year 2010, more than 12.7 million pounds of toxic chemicals such as nitrates, arsenic, benzene, and mercury were dumped into the Mississippi River. Over 50 cities up and down the river rely on it for their water supply. Treated water from the Mississippi is suitable for drinking, but the Minnesota Pollution Control Agency is still working to get the river to suitable swimming and fishing conditions. 

Earth has large reserves of oil underneath its surface that naturally develops cracks, allowing oil to seep onto the surface in low quantities. This is natural and does not harm the environment. However, human interference may cause this to occur on a large scale, resulting in major damage to marine ecosystems. Oil spills occur when liquid petroleum is released into the environment by vehicle, vessel or pipeline due to human negligence. Most animals living in the water or shore die from suffocation, difficulty floating and regulating body temperature, the toxicity from ingesting the oil, and starving to death. To aid in the cleanup of these oil spills, scientists turn to hydrocarbon-consuming microbes that break down the hydrocarbon rings in oil using their enzymes and the oxygen in the ocean.

The United States alone has 32 slaughterhouses responsible for the dumping of 55 million pounds of pollutants into waterways annually. Their wastewater contains solid material such as fat, grease, and manure as well as other contaminants such as nitrogen, phosphorus, and ammonia. These wasteproducts are disposed of my the agricultural industry through spraying it as irrigation over crop fields, further contaminating soil and groundwater. To break down these wastes, anaerobic fermentation is now used. This process degrades hydrophobic lipids contained in the water.