A process and apparatus are disclosed for separating drilling mud and waste materials into pure water and a concentrated solid waste phase which is easily handled and disposed of. The process and apparatus provide for adjusting the pH of the drilling mud and waste materials to be separated, mixing the thus pH adjusted mud and waste materials with a flocculating agent and allowing the solids to settle out. The solids are then removed and further dewatered to produce a relatively dry concentrated solid waste phase. If desired, the clarified water is mixed with finely divided activated charcoal to remove various impurities from the clarified water. The mixture of clarified water and charcoal are then filtered to produce a filtrate stream which is further separated to produce pure water and a liquid phase containing dissolved solids. The pure water can then be reused in the drilling process or safely discharged into the environment.