Petroleum refineries and petrochemical plants all generate oily wastewater to some extent, and the oils contained in those wastewaters can vary widely. Removal of oils from wastewater is normally one of the first and most important step.

Produced water is generated in the process of lifting oil and gas from water-bearing formations–typically sea or lake beds. As oil and gas is lifted to the surface, water is brought along with it.

Meeting water quality specifications for injection or reinjection is essential for protecting the permeability of a reservoir. It is also necessary for developing the water drive required for enhanced oil recovery.