Posted on 23 May 2016
Soil drilling company Haitjema, water utility Vitens and research institute KWR have developed a new method for drilling large diameter groundwater wells.
With the new drilling technique, Expanded diameter gravel well (EDGW), a groundwater well with a diameter of 1.7 m has been drilled successfully in the Netherlands.
Using conventional mechanical drilling techniques groundwater wells with diameters up to 1.2 m can be drilled.
Large diameter wells are needed to achieve a high abstraction rate in fine-sand aquifers and to increase the lifespan of the sources.
In October 2015 the first well was drilled using the EDGW technique at groundwater extration location of Vitens. This involved drilling conventionally at first and then using the new technique to achieve a diameter of 1.7 m from a depth of 53 to 68 m below ground level.
The diameter increase is achieved by washing sand away over the desired depth with a special drill head and sucking it up out of the drill hole.
Diameter up to 3 meter
The new drilling method has proved technically viable and the EDGW capacity tests are promising.
There is potential to improve the drilling process to obtain an even better source. A second test well is about to be drilled, with a diameter of approx. 3 m.
This second EDGW groundwater well will then be taken into use and extensively monitored by Vitens.
Analysis of the measurements will show whether the lifespan of the source is greater than that of conventional wells of far smaller diameter.
The project is part of TKI Water Technology’s programme that stimulates the development of international relevant innovative Dutch water technologies.
This news item was originally published on the website of KWR watercycle research institute.
KWR watercycle research institute
Nieuwegein, the Netherlands
+31 30 60 69 756
Dedemsvaart, the Netherlands
Utrecht, the Netherlands
+31 88 884 61 11