The rivers play a crucial role in the development of the living world of the Danube-Tisa-Cris-Mures region. The preservation and improvement of water quality of surface and groundwater bodies is of utmost importance in the cross-border areas. Water as a vital force is very important to us. Our cross-border rivers: Cris, Mures and Tisa represent shared value and resource for Romania and Hungary.During summer the natural flow of rivers is low. The flow of the rivers slows down due to the swelling and at the same time due to urbanization and industrialization an increasing amount of not always purified wastewater encumbers mainly the Cris and Mures and therefor Tisa as well. Even treated wastewater may have adverse effects on rivers, as it can easily lead to water plant proliferation. Floods in the rivers are unevenly distributed and are usually attributable to heavy rainfall. Floods covering the entire length of rivers have been rarely recorded.An improvement in the ecological condition of our rivers is the established goal of this joint project developed by Waterworks of Arad and Szeged. Improving water quality is a shared responsibility of partners, although technical solutions can may differ. Both companies are constantly striving to meet the priority set out in the EU directives in order to preserve our common natural values.Within the framework of this project, both waterworks have set out to improve the ecological condition of their treated wastewaters. The goal of wastewater treatment is to remove as quickly as possible pollutant and potentially toxic infectious substances in dissolved and floating form, most ofnitrogen, phosphorus and potassium. The purified water can then be discharged into various water courses.With the knowledge of the rules and regulations the partners operate multiple wastewater treatment plants using different technologies and with different efficiency to meet their expectations. The aim of the project is to further develop the operation of 6 wastewater treatment plants in three river sections: Cris, Mures and Tisa (2 plants on each river).Compania de Apa Arad is planning to improve treatment plants at Gurahont and Ineu thus affecting 2 measurement points on Cris (Cil and Ineustatiehidro) and the plants at Arad and Lipova affecting 2 measurement points on Mures (RadnaLipovaandZadareni). In all 4 cases the goal is to increase the efficiency of treatment processes at their facilities. The selection of the measuring points was made taking into account the requirements for compliance with the quality requirements of Ineu, Gurahonţ, Lipova and Arad wastewater treatment plants in order to improve the quality of the Crisul Alb and Mureş rivers and to ensure the long-term sustainability of a proper water quality discharged into the landfill in accordance with the requirements of Directive 91/271 / EEC on urban waste water treatment as amended by Directive 98/15 / EC, aimed at ensuring that the requirements of Directive 2000/60 / EC establishing a Community policy framework water.Szeged VízműZrt. is planning improvements at 2 of their facilities (treatment plants at Algyő and Szeged) influencing 2 measurement points on Tisa (Szeged, TápéikikötőandTiszasziget, országhatár). In addition to procuring traditional tools and equipment, innovative tools are also envisaged for achieving more effective, energy-efficient technological development for the decomposition of organic materials.During the project, SzegediVízműZrt. Will carry out continuous research and analysis in order to develop a joint study of technological developments and changes on both sides of the border, and publish it in a final report.