Application of Multi-Criteria Analysis in the Selection of Individual Sewage Treatment Plants

The development of sewage systems leads to an increase in people’s living standards and an improvement in the comfort of their daily lives. In 2021, the use of septic tanks is still a big issue; many of them are not properly sealed and can be harmful to the environment because of leakage. A good alternative for them is an individual sewage treatment plant. There are many types of such investment. This paper focuses on the selection between three types of sewage treatment plants (a biological wastewater treatment plant with activated sludge and a constructed wasteland) using MCDA–AHP and TOPSIS methods.