A system for recirculating ozonated liquid, comprising: a contactor including at least four inlets and at least two outlets (155,156), the contactor configured for being in fluid communication with (i) a first liquid source comprising a tool at a first contactor inlet and a third contactor inlet and (ii) a second liquid source comprising a fluid delivery system at a second contactor inlet, the second contactor inlet adapted to receive gas that purges at least a portion of an unwanted gas from the ozonated liquid received at the first contactor inlet from the first liquid source, the purged gas exiting the contactor at a first contactor outlet, wherein the contactor is configured for being in fluid communication with the fluid delivery system at a second contactor outlet, the fluid delivery system configured for being in fluid communication with the tool, the contactor draining at least a portion of the purged ozonated liquid in the contactor, the drained liquid exiting the contactor at the second contactor outlet; a first pump configured for being in fluid communication with the contactor via a) at least one inlet of the first pump configured for being in fluid communication with the second outlet of the contactor, and b) an outlet of the first pump configured for being in fluid communication with the fluid delivery system, the first pump being configured for pumping the drained liquid from the contactor to the fluid delivery system connected to the tool, wherein the first inlet and the third inlet are in fluid communication with the first liquid source, and the third inlet in cooperation with the first inlet allows the first liquid source to release the ozonated liquid at an ambient pressure into the contactor by allowing gas to flow out of the third inlet; and wherein the fourth inlet is configured for being in fluid communication with a third liquid source, the fourth inlet receiving fresh liquid from the third liquid source that replaces at least a portion of the liquid drained from the contactor, the fresh liquid being substantially free of ozone. a contactor including at least four inlets and at least two outlets (155,156), the contactor configured for being in fluid communication with (i) a first liquid source comprising a tool at a first contactor inlet and a third contactor inlet and (ii) a second liquid source comprising a fluid delivery system at a second contactor inlet, the second contactor inlet adapted to receive gas that purges at least a portion of an unwanted gas from the ozonated liquid received at the first contactor inlet from the first liquid source, the purged gas exiting the contactor at a first contactor outlet, wherein the contactor is configured for being in fluid communication with the fluid delivery system at a second contactor outlet, the fluid delivery system configured for being in fluid communication with the tool, the contactor draining at least a portion of the purged ozonated liquid in the contactor, the drained liquid exiting the contactor at the second contactor outlet; a first pump configured for being in fluid communication with the contactor via a) at least one inlet of the first pump configured for being in fluid communication with the second outlet of the contactor, and b) an outlet of the first pump configured for being in fluid communication with the fluid delivery system, the first pump being configured for pumping the drained liquid from the contactor to the fluid delivery system connected to the tool, wherein the first inlet and the third inlet are in fluid communication with the first liquid source, and the third inlet in cooperation with the first inlet allows the first liquid source to release the ozonated liquid at an ambient pressure into the contactor by allowing gas to flow out of the third inlet; and wherein the fourth inlet is configured for being in fluid communication with a third liquid source, the fourth inlet receiving fresh liquid from the third liquid source that replaces at least a portion of the liquid drained from the contactor, the fresh liquid being substantially free of ozone.