In the context of Indian urban water, more precisely groundwater, Bore-well is a ubiquitous term. Borewell is essentially a deep hole usually of 9-inch diameter going deep into the earth to tap into the water which is present in what is called the ‘confined aquifer’. It is not uncommon to see borewells going as deep as 1800 to 2000 feet in search of water. Confined aquifers are formed over decades or centuries and the recharge areas of these deep aquifers are usually very far from the point of withdrawal.
On the Other hand, another geological formation called ‘unconfined aquifer’ is the water available in the soil pores at a much shallow depth. The Seepage of this water into the unconfined or shallow aquifer is much faster and the recharge of this water happens very locally. Extraction of this water is much cheaper and usually, the water from the shallow aquifers (Unconfined aquifer) will be much better than the deep bore-wells (Confined aquifers).
The dynamics of formation and recharge of these two aquifers are totally different. Hence, it is very much possible that water may not be available at a depth of 1500 feet in the bore-well (Confined aquifer) but water may be available just 10 feet away at a shallow depth of 15 feet in the open well (Unconfined aquifer)
In this Video, an attempt is being made to explain the aquifers in the context of Urban water and rainwater harvesting. Real-world example is taken to show the availability of water from both the aquifers. The water from the open well is tested for drinking water standards (IS 10500).
A detailed video explaining the economics of Open well (Unconfined aquifer) is here: • Groundwater , Groundwa...
Music Credit: Bensound (www.bensound.com/)
DISCLAIMER: Hinren Engineering or its promoters do not claim any credit for the excavation of Recharge wells shown in this video.