The Sava River within the territory of Croatia is significantly polluted due to the untreated domestic, commercial, public and industrial wastewaters from Zagreb City and the neighboring municipalities, although the Government of Croatia are undertaking water pollution control of the river by constructing and operating wastewater treatment plants in Zagreb City and these municipalities.

Under these circumstances, a master plan was formulated, setting the target year of 2015, and a feasibility study was conducted, focusing on the improvement of the water related environment of Sava River. Technology transfer to the staff of the Environmental Conservation Division has been also provided under this study.