(a) Oleophilic disc skimmers use the principle of oil adhering to a solid surface, and typically include a series of discs that are rotated through the slick. As each disc is rotated through the oil/water interface, oil adheres to the disc surface and is then removed by scrapers mounted on both sides of each disc. Product is collected in a common sump and pumped away. Disc skimmers are typically powered by a remote power pack (hydraulic or air-driven), which results in a light, compact skimming head that is easily transported and highly maneuverable.