The Dutch this month signed a 30-year design-build-operate-transfer peliminary contract for what officials say would be the largest wastewater treatment plant in Europe. The plant, at Harnaschpolder near The Hague, would be designed for advanced treatment, including phosphorous and nitrogen removal and serve 1.3 million people. An existing plant at Houtrust, some12-km away, will be upgraded to include nutrient removal under the same contract, rasing the combined capacity on completion in about 2008 to nearly 50,000-cu-m-hour, says a spokesman for the utility Hoogheemraadshap van Delfland. A consortium led by Paris-based Vivendi Water S.A. will complete financing arrangements and design, allowing it to start construction in about a year, says project manager Christophe Debelmas. Other members of the team include Dutch water distribution firms Delta Water and Waterbedrijf Europoort. Costs are estimated at $225 million for the new plant and nearly $1.5 billion over the life of the contract, including operations and maintenance.