When we were intending to buy what would later become the Trullo EVO, one of the first things we asked ourselves is
They had told us about the car barrels that we could call whenever we needed them. But honestly it seemed to us an inconvenient and expensive solution. Especially because our intention was also to make a part of the land a garden and we would have to call a car barrel every week practically.
That’s when we realized that we would have to dig an artesian well.
We clearly knew what a traditional well was but, to be honest, we didn’t know the artesian well at all.
What is an artesian well
Meanwhile, the name “artesian” derives from a geographical connotation: “artésien”, or “of the Artois” region of France where this type of well, called artesian, has been in use for a long time.
An artesian well is a well where groundwater flows naturally and manages to reach the surface without the need for mechanical means or aids. There are no pumps that pull up the water, but it rises to the surface by itself.
But how is it possible that the water goes up by itself? This is explained in this picture:
According to the so-called communicating vessels principle, once the drilling has been carried out, groundwater naturally rises to the surface to reach the highest level of the other vessels.
Having the opportunity to enjoy an artesian well near your home, has a number of advantages not only economic but also ecological.
A land like that of the Trullo EVO, needs a continuous series of interventions such as irrigation and watering. To draw continuously, especially during the hot season, to the state water resources, would involve a considerable waste of water that, in the long run, affects the world system as a whole.
Having the possibility to use water that spontaneously rises from the subsoil is therefore an ecologically sustainable choice that acts in an optimal way on pollution and environmental impact.
How to build an artesan well
An artesian well is quite deep. In particular, in the area of Ostuni, the aquifer is about 180/200 meters deep.
There are drills that, mounted on trucks or tracks, drill into the ground until they reach the aquifer. The hole is only about 30 cm.
In general, a test drill is performed before the actual drilling is carried out. This is done by making a simple small compressed air hole, so you intercept the aquifer, you understand what depth it is at, what capacity it has and you can get a more precise idea of the type of soil you are dealing with.
At this point, the drilling machine, by rotating a hollow shaft equipped at the end with a toothed chisel capable of drilling the rocks, performs the excavation and at the same time pumps the bentonite mud into the hole in order to avoid the failure of the well walls, bringing the debris to the surface and lubricating the head of the shaft.
When the water table is reached, a smaller diameter tube is inserted in the hole, which will constitute the well itself. The deeper parts of the pipe, at the water table, are equipped with slots so that water can enter. Siliceous gravel is placed in the cavity between the pipe and the walls of the hole, while the most superficial part of the well is cemented, so as to avoid the entrance of sewage water into the well itself.
At this point the artesian well is ready, but it must be purged to extract all the bentonite mud and kept under pumping for a few hours, so as to completely clean it from the silt and sand that pass through the cracked area at the bottom of the pipe.
The artesian well does not appear as a classic well of our collective imagination.
Elements like those bricks placed in a circle, that bucket of wood tied to a rope that goes up and down from a pulley are not in a modern artesian well.
However, the artesian well does its duty and it is thanks to this work that we can make the best use of water for our land and for all the crops present.