Pilot Desalination of Brackish Ground Water and Injection of the Brine in a Deeper Consolidated Aquifer in the Netherlands

Vitens, the largest water company in the Netherlands, supplies 330 million cubic meters high quality drinking water to 5.4 million domestic and industrial clients. Water abstraction at the 100 well fields is performed with respect for nature and the environment at all times.   In the Northern part of the Netherlands problems have arisen through salination of three well fields. One well field was left due to high salinity. Two others were reduced in capacity to stabilize the salination process. Due to the reducing of capacity and lightly growing water consumption new sources have to be explored. Different strategies are investigated at this moment.   One strategy is to desalinate brackish groundwater from the abandoned well field with reverse osmosis membrane techniques. Solutions have to be found for the disposal of the left brine residuals. By Dutch law it is not allowed to dispose brine in large amounts on surface water. There are possibilities to inject the brine into a deeper aquifer below a thick clay layer.   A pilot project will start in January of 2009. During one year about 0.5 million cubic meter brackish water will be extracted and treated with reverse osmosis. As it is not allowed to infiltrate any non-natural products into the subsoil of the Netherlands no anti scaling products will be used. In the test period about 220.000 cubic meters brine will be injected into the deeper aquifer. A monitoring program will start on the different types of water flows. Also the effects of the bubble of brine in the deep aquifer will be monitored. Aim of the project is the show that it is possible to use this technique of treatment and disposal of the brine. Another aim is to test and understand the legislation rules before a large-scale project is started.