The ÉlőDuna project is currently the largest environmental investment to be implemented in Europe by 2010, which will fundamentally modernise the waste water treatment system and technology of Budapest, resulting in a significant increase of capacity, and as a result, the water of the Danube at Budapest will be clean again within a few years.

Beside its environmental significance, the project is not only outstanding in terms of its total budget, but it is also considered to be one of the most outstanding European projects in terms of the seven project elements to be constructed, the public procurement processes involved and the numerous cooperating partners to be included.

The wastewater treatment plant to be built on the northern part of the Csepel Island will ensure that the proportion of the biologically treated wastewater discharged to the river will rise to 95%, from the current value of 45 % due to the fact that the plant will be able to treat 350 thousand m3 of the daily 600 thousand m3 wastewater. The technology to be used will allow the complete vicinity of the plant to remain a green belt zone by occupying only the smallest area possible from the surface available. The plant will employ a closed-loop technology, complying with stringent noise and odour emission norms.

From the 790 thousand households of Budapest, approximately 600 thousand cubic meters of wastewater is discharged into the Danube every day. Only less than 50 % of this amount is treated biologically with the present capacity of the capital’s wastewater treatment plants. Taking into account the amount of rainwater, it can be concluded that the larger proportion of wastewater is discharged into the river without biological treatment. This is not only a significant environmental load, but also has public health effects on the life of citizens living in the capital and along the banks of the Danube.

The Central Wastewater Treatment Plant will provide an answer to these problems, which, along with the necessary facilities, will be built by 2009 on Csepel Island. With the implementation of this environmental super-project with a budget of €529,1 million (of which €428,7 million was acknowledged to be cost by the EU Commission) and €304,7 million in support from the Cohesion Fund, Budapest – converging to numerous other European cities – will also have the capacity suited to manage the wastewater treatment services of the city with a population of 1,8 million.