Works to extend the thermal waste utilisation plant at Zwentendorf/Dürnrohr started on schedule, in June 2007. They involve the construction of a third line to supplement the two lines already operated by the plant, in response to a marked growth in the garbage volumes to be treated by EVN Abfallverwertung NÖ, which has caused the plant to be constantly operated at its full capacity on a permanent basis.

Accordingly, the plant is to be extended from its current output of 120 MW to 210 MW by 2010. The third line will be constructed in parallel with the two existing lines and will mirror their technical concept. A new addition will be the so-called “initial bunker” which is designed to hold the additional waste as an extension of the current waste bunker. This initial bunker is currently under construction. Excavation works, already completed, had to accommodate walls which will reach down to a depth of 21 m, submerged below the shallow groundwater table of the Tullnerfeld plain, so that they need to be designed as special walls of a thickness of 1.20 m – a major engineering feat since the bunker naturally needs to be totally leakproof.

The existing bunker will be given a longer craneway. The two cranes, each designed to a capacity of 10 cubic metres, will get a third clamshell crane of the same type. The requisite conversion works, which made for an immense structural engineering challenge, have meanwhile been completed.

Same as Lines 1 and 2, the new Line 3 will incinerate waste and generate steam which will then be fed to the Dürnrohr power station to produce electricity, district heating and process steam for industrial use. With this project, EVN Abfallverwertung NÖ will not just add another substantial contribution to environmentally friendly waste disposal but will, through the combined-cycle operation with the Dürnrohr station, provide for further savings in the consumption of fossil fuels and reduce CO2 emissions: aided by the future extension, it will be possible to save on 100,000 metric tons of coal and 10 million cubic metres of natural gas per year.

The autumn of 2007 saw the completion of the ground slab for the Line 3 boiler and for the wet and dry flue gas cleaning system and the awarding of contracts for the plants of the boiler and flue gas cleaning systems. Assembly of the boiler and flue gas cleaning systems will be started in March 2008.