A screen can now be applied to horizontal pipes as well
An innovative but tried method now makes it possible to use an artificial screen for a horizontal filter pipe as well. In this process, a sand pack that has been made artificially homogeneous is placed around the pipe. This makes it possible to calculate the proper size of the filter crevice again. When constructing an HDDW, the sand pack can be applied both above and below ground. An artificial screen prevents sand delivery and keeps the capacity at optimum level.
The choice between a natural and an artificial screen makes it possible to install the HDDW in almost any soil.