A mobile chamber has an inlet for receiving polluted water and an outlet for pollution-free water to flow out. A mobile trap operating system includes an output pump, an input pump, a pollution tank, and a liquid tank, all operably connected to the chamber. Within the chamber is a collection reservoir with a skimming edge for skimming off floating pollutants such as motor oil, other hydrocarbons, and detergents. Alternative embodiments include a screen, baffles, and/or pivotal filter for further separating the pollutants from the water. A method for separating the pollutants from the water includes directing the water from the water tank at the pollutants and into a collection pool of polluted water, drawing the polluted water into the chamber, receiving the skimmed pollutants from the collection reservoir into the pollution tank, and receiving the pollutant-free liquid from the chamber into the liquid tank.