Feasibility of Sewage Treatment plants: a case Study of co-treating with Septage in Indian Cities

IJEP 43(6): 552-560 : Vol. 43 Issue. 6 (June 2023)

Anil Dutt Vyas*

Manipal University, Department of Civil Engineering, Jaipur, Rajasthan – 303 007, India


Since India got independence water supply and liquid waste management projects in the country are not integrated with each other. The biggest challenge is that almost 63% of India’s sewage, that is 38,791 MLD is not getting treated. with 1200 sewage treatment plants (STP) in India only 612 STPs are operational. Ministry of Urban development has estimated that almost 25,000 MLD of STP capacities is under utilized in 400 cities in India. Co-treatment of septage at existing STPs with spare capacity is an emerging domain of Government of India. Four STPs used for co-treatment or which are planned for co-treatment in different states of India are selected for this study. Since limited information is presently available on compatibility of STPs for co-treatment in India, varying concentration of biochemical oxygen demand (BOD) is taken as key factor for analyzing this study to develop a new mathematical model. Optimum figure on on-site sanitation population which can be catered through the STPs is obtained by changing the concentration of BOD of septage and sewage. Model also predicts the percentage of septage volume and number of desludging trucks used. At around 300 mg/L of influent sewage BOD and 30,000 mg/L of septage BOD, the STPs are not in a position to accommodate any population.


Biological oxygen demand, Co-treatment, On-site sanitation, Population, Septage, Sewage treatment plant


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