Crude oil is a fossil fuel formed from long-dead organisms subjected to intense heat and pressure underground. This resource is the main ingredient in the production of gasoline, diesel fuel, lubricants, kerosene, propane, and asphalt. All of these products can be made in a single refinery through a complex branching series of chemical processes. The central refining process is atmospheric distillation whereby the crude oil is fractured into different components based on their differing boiling points. Each of these fractions will be sent along to separate process to be turned into the different oil products. Therefore, remediation of refinery wastewater from these different processes can be quite complex.