a system for cleaning vessels that have been contaminated with oil field drilling and production waste materials such as oil well drilling fluid or hazardous waste using recycled wash water . as dirty wash water accumulates in a vessel during cleaning , it is transferred to a settlement section of the waste receiving barge . a cationic polymer is injected into the suction side of a waste water pump during transfer of dirty fluid from the vessel to the receiving barge . the polymers react with fluids to begin an initial settling process within the waste receiving barge . decant water is subjected to secondary settlement and secondary chemical treatment after it leaves the primary settling section of the waste receiving barge . the laundered water is returned to the wash water storage facility for reusing and cleaning the same vessel or additional vessels . in this fashion , waste is continuously concentrated in the receiving vessel for ultimate disposal at a remote site and wash water is recycled for reuse .