A system for removing paper and other contaminants from shredded plastic film, the system comprising a plurality of receptacles, means for moving the plastic film sequentially through the receptacles, means for recirculating aqueous solution through each of the receptacles, and means for filtering the recirculated aqueous solution, said recirculating and filtering means comprising at least two independent recirculation modules, each recirculation module having means for recirculating and filtering an aqueous solution and for restricting carryover of solution between modules, at least one recirculation module having means for introducing flocculant into the solution in response to measured or observed turbidity.