Abstract: A method of dewatering a mixture of coal tailings, water and contaminants comprising the steps of (a) providing a tank having a base surface and introducing said mixture of coal, tailings, water, and contaminants to said tank and allowing said coal tailings to settle on said base surface, (b) removing the coal tailings from said base surface of said tank along with water and contaminants and then separating said water and at least some of said contaminants from said coal tailings wherein said separated contaminants are suspended in said separated water, (c) adding an agent selected from one or more of the group consisting of a coagulant and a flocculent to said water and suspended contaminants separated from the coal tailings in step (b), (d) allowing the agent added in step (c) to coagulate or flocculate with the suspended contaminants to form a coagulated or flocculated mass and a quantity of supernatant water, and (e) separating the coagulated or flocculated mass formed in step (d) from the quantity of sup