Abstract: A settling tank for drilling fluids is provided, having a first compartment. The first compartment has confining walls, an inlet, an outlet weir, and a source of secondary fluid. At least one of the confining walls has a downwardly sloped confining wall. The inlet is provided for supply of drilling fluids into the first compartment. The outlet weir is positioned in at least one of the confining walls. At least one source of secondary fluid is provided. The source of secondary fluid is configured to direct fluids down the downwardly sloped confining wall towards a collection area. By directing fluids down the downwardly sloped confining wall, solids that may accumulate in the compartment are more efficiently moved towards the collection area where they can be removed. The apparatus and method disclosed herein describe an efficient approach to processing drilling fluids on site.