In the case of water between water -resistant layers, drilling well can be to a depth of 90 meters.
Drilling of a filter well is carried out by a dry way. The drill crashes into an aquifer with a sufficient amount of water, then a casing is inserted into the resulting well. A filter column is located on the bottom of the pipe. A filter for water purification is placed in it. The type of filter is selected, focusing on the character of the sand. For this, a test water fence is made.