NOVELTY - The system has a fiberglass baffled reaction chamber (250) coupled to a vent and comprising a gas container. A seal seals openings in a containment vessel in fluid communication with ambient air except for the vent, a liquid inlet and a liquid outlet. An ozone generator is operably coupled to a control system, and controllably produces ozone and supplies the produced ozone to the reaction chamber. The control system controls the production of ozone by the ozone generator based upon a determined parameter indicative of odiferous gasses emitted from a gas outlet.    USE - Ozone-based system for reducing odiferous gasses e.g. hydrogen sulfide and residual ozone, emitted from an odor source i.e. wastewater lift station or pump station. Can also be used to reduce ammonia, carbon dioxide and methane.    ADVANTAGE - The reaction chamber with ozone treats hydrogen sulfide and other foul odors. The system does not require a fan or blower to suck or force the foul gasses from a wet well through the reaction chamber, thus making process more energy efficient. The system monitors volume of flow and direction into and out of the wet well via sensors, thus allowing to make ozone when foul gas is being discharged by a rising liquid level and shutdown of ozone production when the liquid level is being fallen and ambient air is being pulled into the wet well, and hence making the process more energy efficient and preventing excessive ozone, which can damage wet well components from entering the wet well in any significant quantity. The system monitors residual discharge of hydrogen sulfide and ozone with transducers and using Proportional-Integral-Derivative (PID) closed loop control with a Programmable Logic Controller (PLC) for control of ozone production. The PID closed loop monitoring and control allows for energy efficiency manufacturing of the ozone production. The system allows highly enriched oxygen to be sparged into liquid to decrease formation of hydrogen sulfide when the ozone is not being produced, thus benefitting odors being treated at a site due to aeration and giving downstream benefit due to decreased hydrogen sulfide production.    DETAILED DESCRIPTION - The ozone generator is one of a high voltage plasma ozone generator and a UV ozone generator.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of components of a reaction chamber and exhaust.    Wastewater well (205)    Wet well vent pipe (210)    Nozzle (215)    Gaseous mixture (230)    Reaction chamber (250)    Sensors (265)