A complex of basic technological objects, designed directly for treatment of wastewater and auxiliary facilities located at one area, necessary for supply of electrical energy, water, working conditions and servicing of a wastewater treatment plant.

In terms of the type of wastewater treatment methods and related processes, wastewater treatment plants are divided into the following types: mechanical, chemical, biological, with increased biogene removal.

• Biochemical oxygen demand (BOD)
• Chemical oxygen demand
• Population connected to wastewater treatment plants
• Biological wastewater treatment plant
• Chemical wastewater treatment plant
• Municipal wastewater treatment plants
• Municipal and rural sewage wastewater treatment plant
• Mechanical wastewater treatment plant
• Wastewater treatment plant with increased biogene removal