A system for removing hydrocarbons and other contaminants from sand and/or drill cuttings includes screening large debris from a first loading inlet hopper (101) to a screen covered receiving hopper (102) that may contain a chopper and chemical additive nozzles (105). A first inclined auger (104) receives the material from hopper (102) at its lower inlet port and conveys the material upwards dropping it into a hopper (106) and then to a unit (107) either of which may include a crasher (106). Unit (107) includes an eductor (109) which feeds the screened and treated sand slurry to desanding units (112) such as hydro cyclones. The underflow from the desanders is sent to an auger tank's (114) first compartment (113) while the overflow is sent to its second compartment (115) where a flow distributing conduit (117) that disperses it over the surface of both compartments (113), (115). The auger tank (114) employs horizontal augers (116) that are arterial both the first and second compartments (113) and (114). Second compartment (115) contains inclined plate separators (118) and sparging tubes (119). Overflow from auger tank (114) is sent to another two compartment separator (120). The first compartment (121) which receives the overflow from auger tank (114) includes a weir-type partition topped by an oil skimmer (123) connected to a voiding pump (125) feeding an oil tank (124) and defining a horizontal gap with the two compartment separator tank bottom as at (121). Clean water passing through the bottom weir is allowed to spill over the top of the an uppermost weir in the two compartment separator tank (120) into clean water collection tank (122) from when it is recycled to other components of the system. The undertow recovered from the auger separation tank (114) may be further decontaminated by sending it via an inclined conveyor to a serial connection with a second system similar to the one described herein above.