Ewalt Sequential Batch Reactor system is a modern approach to treat domestic and industrial wastewater. ESBR is a automated PLC based biological treatment plant for biodegradable wastewater. ESBR represent a variation of the activated sludge process. Like any other activated sludge process, ESBR works by developing a mixed culture of bacteria, which is effective in removing BOD, COD and nutrients commonly found in wastewaters. ESBR can treat a wide range of domestic and industrial wastewater, at flows ranging from a 1m3/day to 1000 m3 per day in a single unit. ESBR is a single reactor system. These units are normally installed in situations where there are space constraints & compatible work force is not available in remote locations. The ESBR can treat domestic as well as small industrial effluents to a very high standard like ≤10mg.litre BOD discharge. Ewaltz Sequential Batch Reactors are controlled and monitored by a Pre Logic control system for easier, safe & automatic operations. The operation principal in ESBR is the same “Batch of each process & reaction will take place in series, in a single reactor or batch chamber. The waste water from common collection tank will flows into a set of ESBR, and after the process of fill, react, settle, decant, idle, 95% COD could be removed .There are some sets of standby electromechanical rotary which could make the system trouble free & smooth.