This chapter summarizes the three groups of floatable and their removal strategies as follows: organic particles and fibers; oil, grease, and fats; and gas bubbles. A good oil removal system has the following features: removing oil, taking care of suspended solids, taking care of tight emulsions, providing a good turndown ratio, able to handle the flow surge, and able to handle the oil content surge. Stagnant oil gravity separation is done in large ponds when the feed water flowrate is very small in comparison with the oil gravity separation pond. The chapter shows a gas-assisted flotation system, and liquid–liquid hydrocyclones. Centrifuges separate oil from water through the combined effects of two mechanisms: more effective separation by exerting several thousands of g-force, and shallow separation distance by placing discs few millimeters apart from each other. There are two main types of centrifuges as follows: stack type, and horizontal type.