One of Mira’s specificity is the quality of the spring water, which is almost as old as the two-headed chimera! Indeed, – hardly – 22000 years ago, this water ran through the soils of the Arcachon Bay and formed an underground reservoir. Today, thanks to our highly resourceful malter-brewers, this water is mira-culously used to brew our Mira!
It was during the ice age, long before the Lascaux man [17,000 years ago], that the rain infiltrated the soil and gathered under a rocky limestone. The water went slowly to the depth, through the grains and the cracks of the rock.
This water is now pumped through Mira’s borehole, between 240 and 300m deep. The pressurized aquifer water, protected by a large and impermeable layer of clay, gets up the borehole at 14 meters from the surface. Warmed up in the depth, its temperature when it gets out is 21°. It is a great quality water, containing the right amount of mineral salts, free from pollution.
The hole was drilled from February to April 2017. It is made up of a stainless-steel tube, full up to the tank, and of a tube with an inlet filter from 240m deep. It is a steel tube with small gaps allowing the water to go through. The tube is also surrounded by gravels in order to filter water.
It has been subjected to a number of investigations (pumping, well logging…), for example a video camera was used to check the tube was in good state.