The dual axis grinder includes a support frame with a plate and a mast. The mast is connected to the boom of an excavator and to a hydraulic stick control cylinder. An auger tube is journaled in a bore through the support frame plate for rotation about a vertical axis. Auger flighting may be attached to the auger tube. A central support housing is attached to the bottom of the auger tube. Two cylindrical drums with grinder teeth are journaled on the central support housing for rotation about a horizontal axis that intersects the vertical axis. The auger tube is rotated by a reversible hydraulic motor. The cylindrical drums are driven by one or two reversible hydraulic motors. Hydraulic fluid is provided to drive the two drums cylindrical through a rotary hydraulic manifold. Chemicals to treat environmental contaminates are supplied through a nozzle adjacent to the cylindrical drums.