Denys is building 7.6 km of sewers on the left bank of the Canal of Willebroek and the Senne River in North Brussels, as part of a Build-Own-Operate-Transfer (BOOT) contract awarded to Aquiris, a Franco-Belgian consortium led by Veolia Water for the Brussels North wastewater treatment plant. The entirety of the sewers is constructed by no-dig techniques. There are 11 rectangular start and exit shafts and 15 pipejacked sections built at a depth of 10-18 m, with variable diameters (900 cm, 1.6 m, 1.8 m, 2.2 m and 2.5 m), in alluvial water-bearing ground composed of sand and grind, with lime and clay layers. Five Herrenknecht mixshield TBMs, four already owned by Denys and one newly purchased machine, are being used to excavate the sewer sections. The longest section totals 1,023 m and is driven with the new 2.2 m-diametre TBM. Laser guidance is provided for each drive by SLS-RV systems from VMT GmbH with reinforced concrete pipes supplied by Socea. Warman hydraulic pumps and 6" to 8" discharge ducts remove the slurry. Difficult conditions under Leopold II tunnel requiring to clear wood piles at the cutter head through a man-hole air lock access. Glassfibre rebar cages supplied by Fortius to allow smooth, efficient arrival of TBM at exit shafts. Total investment by Aquiris will be around EUR290 million. Sewers to be complete in September 2005. The plant will be commissioned in September 2007. Visit www.denys.com, www.herrenknecht.com, www.vmt-gmbh.com and www.fortius.be 35/04.