The article describes the features of wastewater and water treatment plants in settlements. An example of decentralized wastewater treatment with the presence of two treatment plants in an urban-type settlement with a population of 14.4 thousand people was considered. The composition of buildings and structures for wastewater treatment plants for settlement was proposed. As a result of the research, the most appropriate technological scheme for wastewater treatment, sludge treatment and disposal were developed. The efficiency at each treatment stage was analyzed. It is concluded that the described technological scheme of wastewater treatment for settlement meets the fishery standards for effluent discharging into the river.