An oxidation filtration system for cleaning groundwater, the system having an aeration tower and a filtration tank. Within the filtration tank is an upper chamber and a lower chamber. Contained within the lower chamber is a plurality of Styrofoam.TM. filter media. Separating the upper chamber from lower chamber is a filter media mash which keeps the filter media from entering into the upper chamber. The aerated water from the aeration tower enters into the base of the lower filter chamber and rises through the filter media into the upper filter chamber. As the water passes through the filter media, the dissolved solvents fallout of the groundwater and attach themselves to the Styrofoam.TM. media. An automated back flushing and clarifying process is also provided using a back flush port and a clarification port, a higher level water sensor in the aeration tower and a programmable logic controller. The controller opens and closes the back flush and clarification port depending on the settings within the resident software, the controller interfaces with a remote computer to remotely operate the back flushing, clarification and filtering of the groundwater. The controller receives signals from the sensor to determine emergency back flushing requirements. The controller operates at a minimum one, and maximum five oxidation filtration systems at one time.