How to fill a well around a pipe

Hello! We drilled a well, and the question arose of how to fill it up, since there were 4-5 cm gaps on each side between the casing and the ground (trunk diameter - 200 mm, and pipes - 125 mm).

Rustam.

Answer

First of all, you need to understand what you plan to fall asleep - the well (the aquifer of the trunk) or the so-called annulus (the rest of the pit). In the first case, filling with fine gravel is used (approximately 5X20 fraction or even less). It will create a framework for smaller sand inclusions and will not allow clay to float on the filter. In dusty sands, it is better to add coarse river sand in a 3: 1 ratio to the gravel. This will increase the throughput of the filter zone. Dumping is made low - otherwise flow from the upper aquifer is possible. As a rule, in order to create a high-quality natural filter, 12-14 buckets of the mixture will be enough.

As for the annulus, it is best to fill it with clay - it will allow you to create a reliable waterproof castle. At a distance of 1.5-2 m from the surface, clay can be changed to sand. Such a trick is needed to obtain a drainage channel through which water from the pit will go into the upper layers of the soil. Finally, I would like to recall that when backfilling the casing pipe, it is necessary to strictly monitor its vertical position. Otherwise, there is a possibility of grinding the walls with a retaining cable or damage to the filter by the pump housing.

Detailed information on how to equip a well can be found in this article:https://aquatech.tomathouse.com/en/vodosnab/kolod-skvaj/skvazhina-na-dache-svoimi-rukami.html