At the waste water treatment plant (WWTP) Harnaschpolder a pilot with the name ‘Delft Blue Water’, investigates the possibilities to produce clean water, in a sustainable way, for the direct environment (canals) and the green houses (irrigation water). Delft Blue Water is a cooperation between the Delfland Water Board, Delfluent Services B.V., Evides Industriewater, Rossmark Water Treatment and Veolia Water Netherlands. Together, these five organizations investigate a sustainable alternative for the sweet water supply in the the Delfland Water Board area. Parallel to this investigation, the Technical University of Delft executes scientific research.
There is an increasing demand for sweet water in the the Delfland Water Board area. Besides the slow saliniszation of the area, the greenhouse industry of the Westland requires more and more good quality irrigation water. Up to now, the greenhouse sector abstracts brackish groundwater from the first acquifer and desalinizes this water, after which the salty concentrate (brine) is pumped back into the second acquifer. Although this is actually not permissible, this practise is tolerated by the legislator given the non-availability of financially-economically feasible alternatives.
On the other hand, WWTP Harnaschpolder discharges the treated waste water (effluent) into the Northsea, while the Delfland Water Board has to import sweet water from neighbouring areas to flush the polder canals. Under the name “Delft Blue Water” the project investigates the useful application of this effluent. The investigation aims at testing the production of flush water and irrigation water in a sustainable and cost effective way.
In the demonstration hall, which is built at AWZI Harnaschpolder, per hour 50 m3 of effluent can be used for research. At this moment, two research lines are operational in this hall, one reference line and one innovative line. The reference line, operational since April 2010, consists of a combination of proven technologies. The innovative line, operational since August 2010, consist of a combination of innovative technologies, which have not yet been applied in the practice of treating effluent. At the moment a second innovative line is under construction. The pilot will be operational for four years. www.delftbluewater.nl