Ocena ekonomicznej efektywności komunalnej oczyszczalni ścieków w gminie Sokoły

Two methods for evaluation of economic effectiveness of water pollution control investments, as illustrated by the Podlaskie voivodeship municipality of Sokoły, are discussed in the paper. They include costs-benefit analysis (CBA) and cost-effectiveness analysis (CEA). Initially, an analysis of the level and structure of investment expenditures incurred on construction of the municipal wastewater treatment plant is carried out. It shows that expenditures on bioreactors and the technical building jointly constitute the highest share of the total costs. In turn, analysis of the structure of operating costs of this wastewater treatment plant show that electric energy consumption costs as well as remuneration costs compose the greatest segment of the total real operating costs. Evaluation of costs-benefits analysis of construction of the municipal wastewater treatment plant is carried out by means of the absolute effectiveness index. The ecological effect of this wastewater treatment plant was expressed by the level of losses generated by pollution of the water environment avoided in consequence of operations of the wastewater treatment plant. The nation-wide unit loss index was applied to determine the level of the avoided losses. Thus calculated, the E absolute effectiveness index complied with the effectiveness terms, i.e. E ≥ 1. The cost effectiveness index for the municipal wastewater treatment plant in Sokoły was also determined. This index corresponds to the annual unit wastewater treatment costs.