Due to the considerable costs involved in industrial wastewater treatment, the introduction of open (low-discharge) and closed water circulation systems is the most sensible way to prevent environmen-tal pollution at industrial companies. Since the level of circulating water treatment can be much lower than that required for discharge into a water body, the installation of closed water circulation systems can achieve both the economic and total effects of environmental protection. Despite the seemingly obvious advantages of this approach, it requires a serious feasibility analysis. The life cycle costs of a construction project can be estimated according to GOST R 58785-2019 Water Quality. Life Cycle Cost Estimation for Efficient Operation of Water Supply and Sanitation Systems and Facilities. However, at the initial (pre-project) stage, the analysis can be based on benchmarks. Large industrial companies make extensive use of foreign estimation methods. The paper presents the results of a feasibility analysis obtained using different methods to justify investments in the reconstruction of wa-ter treatment facilities at an oil refinery.