The goal of sewage treatment systems is to reduce the concentrations of organic pollutants in raw sewage such that the clarified waste can be discharged into natural bodies of water without disrupting the ecosystem. While liquid sewage can also result from agricultural and industrial operations, Oxford's is primarily domestic, resulting from everyday human activities such as showers, sinks, and toilets. The City of Oxford Sewage Treatment Plant treats Oxford's three million gallons of sewage per day using a combination of two microbial processes known as aerobic digestion with activated sludge followed by anaerobic digestion .
Raw sewage enters the plant via large, underground pipes .
It is initially filtered to remove large, non-biodegradable solids by passage through bar screens . The resultant debris is deposited in Rumpke dumpsters and hauled away to the landfill. The liquid component of the sewage is piped to a large tank for grit removal where large particles of sand and grit settle out. Resultant effluent then goes to sedimentation basins where more sedimentable solids and grease are removed via settling and microbial degradation. The clarified sewage then enters the activated sludge component of the treatment plant.