This work is concerned with the detailed study of Asia's largest sewage treatment plant of 345 Million Litre per Day capacity based on Up flow Anaerobic Sludge Blanket reactor, installed at Bharwara, Lucknow, Uttar Pradesh, India. The performance evaluation and design analysis of the sewage treatment plant has been carried out to comment on the adequacy of design and capacity. It will also prove quite useful as its a compiled information for ready reference in the area of wastewater engineering.