Besides the fact that it is illegal to dispose of used oil improperly, there are several other good reasons to dispose of it correctly. Recycling used oil conserves future oil supplies and reduces our dependence on imported oil. Approximately 42 gallons of crude oil are needed to refine 2 quarts of lubricating oil. Furthermore, improperly disposed used oil is a hazardous waste. Oil poured into the ground or into a storm drain will eventually find its way to the nearest stream or river and ultimately contaminate groundwater.
Oil pollution can be extremely detrimental to aquatic ecosystems.
Fish can be smothered by oil coating their gills or can be killed indirectly by reduced resistance to infection. Bottom-dwelling organisms such as oysters and clams can be smothered directly by settling of oil suspensions or indirectly by the reduced oxygen levels caused by coating of the water surface. Oil can stunt or kill marsh vegetation or submerged grasses. In addition to initial effects, once the oil begins to dissolve, toxics can be released, exposing marine organisms to potentially carcinogenic matter. It does not take a large quantity of oil to cause serious damage.