(ANSA) - BELGRADE, JANUARY 20 - The authorities of the Serbian capital Belgrade have signed an agreement with the China Machinery Engineering Corporation (CMEC) for the realization of a waste water treatment plant for the city of approximately two million inhabitants, local media reported. The initial stages of the project will cost 271 million euro, the construction of the plant between 400 and 500 million euro and another 100 million will be invested to build four more waste water treatment plants, the news agency Beta reported. Belgrade is the only European city that does not have waste water processing plant in function, the Serbian minister for Construction and Infrastructure Zorana Mihajlovic said, anticipating that a financial contract related to the project will be signed within six months and the research will begin immediately. The goal is to have the treatment system operative in five years after signing the financial contract. Mihajlovic recalled that some 190 million cubic meters of waste waters are ending into the Sava and Danube rivers every year, the agency Beta informed.