Vitens is applying a smart Freshkeeper well at the SUBSOL reference site in Noardburgum, Friesland, Netherlands. The Noardburgum well field was abandoned in 1993 because of salinization and Vitens is evaluating options to reopen the well field to fulfil the water demand in the area.
The Freshkeeper extraction well consists of three separate well screens: one for freshwater extraction, one for saltwater interception (to prevent saltwater intrusion in the freshwater filter screen), and one to dispose of the saltwater in the underlying (saline) aquifer. The smart well has been in operation for a full year now and has produced around 500.000 m3 freshwater, while intercepting and disposing about 30.000 m3 saltwater during parts of this period. Electrical conductivity is monitored online in six monitoring well screens along the well, providing insights in the behaviour of the groundwater system. An important finding is that saltwater intrusion is a very slow process at Noardburgum and that it is not necessary to perform EC measurements every day. This helps to simplify the automated control unit of the smart well in the future. In the coming months the Subsol team will perform several tests to find the most robust way for automated control and operation of the well.
In addition to the above work, preparations are made for full-scale application of the Freshkeeper concept and reopening of well field Noardburgum in 2018/2019 (2 million m3/year freshwater production). The project-team has set up a regional scale groundwater model and will run future scenarios in the next month. This modelling work will provide insights in the regional hydrological effects full-scale application, amongst others in relation to one of the nearby well fields. If proved positive, Vitens will start preparations for reopening the well field in 2018.
This article belongs to D1.2