Diseases carried by animals and which can be transmitted to humans are called zoonotic diseases. Diseases become waterborne when animal feces enter a water supply system. Runoff from animal farms contaminates surface water quality by flowing into water systems, either directly from livestock feces or from precipitation runoff. “Livestock farming depends on the use of antibiotics, vitamins, fertilizers and pesticides. Because of this, it is possible to produce more animals and crops by avoiding the natural conditions they would normally need to survive and thrive. Having these animals stuck in small areas with a large amount of other animals causes stress. For example, the use of antibiotics makes it possible to confine many animals to a smaller area where the disease would normally contaminate or kill the animals. Using fertilizer allows the farm to grow as many crops as it wants if the land is cultivated.