Artesian water — Explainer video

Transcript

Artesian water: when the spring rises on its own.

Artesian water is groundwater under pressure. As soon as a borehole opens the way, it rises on its own. The name goes back to the Artois region, where such wells were drilled as early as the 12th century.

Three conditions must come together: a permeable layer of rock, dense layers above and below it and a catchment area that lies considerably higher than the well or spring. The trapped water “wants” to rise to the height of its catchment area.

Does it always bubble up on its own? No. Without a pump, it only flows out if the pressure level lies above the ground surface. Otherwise the pressure merely reduces the pumping lift: a pump is still needed.

Artesian water is considered well protected. The covering layer acts like a lid, and as long as water is rising in the borehole, nothing can seep down from above. But this protection is not absolute: the covering layer has to be impermeable and the well properly constructed.

“Artesian” is not a seal of quality. The word describes the pressure underground, not the mineralisation or purity. An artesian water can be very pure. But it is not inherently healthier.

Natural mineral water must come from an underground water resource that is protected from contamination. Covered reserves under pressure meet this requirement particularly well, but an artesian origin is not a prerequisite. What matters is the protection, not the pressure.

The water of the Castels spring in Mels seeps into the ground at more than 2,000 metres above sea level. It travels through the rock for around twelve years. At the end of its journey, it is a naturally alkaline mineral water with a pH of 8.0.

More on this in the Piz Sardona Academy.