What is bore well water?
Bore water which is also commonly known as ground water is amongst the most common source of water that is used in India. This bare well water is generally rainwater that gets absorbed by the ground and seeps into the layers of earth. It gets trapped within the layers of rock.
This water is brought to the surface by drilling the ground and pumping water from aquifers. When such water is pumped out it carries various dissolved salts, chemicals and microorganisms such as bacteria that can be very harmful for human health in case of continuous consumption.
Bore well water can be safe to drink at times but is definitely not pure in its natural extraction form. This is because of the water hardness and high levels of contamination. Apart from bacteria and viruses, heavy metals such as lead and fluoride can cause drastic harm to human health. A combination of these unwanted components with calcium and magnesium cause water hardness that makes the taste sour.
An aquifer refers to water holding permeable rock or clay that helps in holding ground water. The amount and level of contaminants that are present in this water is based on the depth of the bore well.
What are the 2 main types of bore wells?
The bore wells can be majorly classified into 2 main types- Deep and Shallow
Deep bore wells are generally used when an aquifer is below 20 meters from the surface. The quality of water in deep bore wells can be drastically affected by a high concentration of naturally occurring hazardous chemicals and minerals due to the depth of storage. Shallow bore wells can be used for pumping water that is below 15 meters. Since the water of shallow bore wells is not protected by layers of clay, soil or rock the microbial and toxic chemical contamination levels are very high that makes this water unfit for human consumption.
Water contamination in bore well water:
Water contamination is a major problem faced by regions that largely depend on bore well water for consumption. The water that is extracted can carry substance that can cause serious health issues. The level of total dissolved solids is generally much higher in bore well water as compared to municipal water or tank water. These high levels of contamination can lead to the water tasting extremely saline and often very difficult to consume.
Water received from any source should always go through a purification process. Consuming clean and pure drinking water not only helps the body prevent any disease caused due to regular consumption of contaminated water but also helps the human body fight off any pervading bacteria and viruses.
Technologies to filter bore well water:
Reverse osmosis and ultra violet filtration systems are the most commonly used yet advanced purification technologies that are used to treat bore well water. Water with low levels of total dissolved solids can be treated using ultra violet purifiers that eliminate all bacteria and microorganisms that may exist in the water with the use of ultra violet light rays.
Reverse osmosis technologies help in adding back minerals such as calcium and magnesium in the purified water. This helps increasing the effect of water consumption in a positive manner. Using a combination of the two technologies can help removing any excess and unwanted solid contaminants while adding back essential minerals at the same time.
Bore well water for agriculture:
Apart from consumption for human needs, India is primarily an agrarian country where farmers highly depend on ground water for irrigation. There has been a continuous rise in the population of the country that creates a scarcity for water levels. Urbanization and decrease in land holdings have together contributed to the need for digging deep bore wells. The levels of ground water abstraction are constantly increasing with the use of underground aquifers in the earth surface.
However, even with the increasing demand for bore wells it is important to identify a correct site to dig a bore well in order to prevent future damages. Vertical Electric Sounding is amongst the most common geophysical method used to explore domestic bore wells. There must be enough open area around the potential location in order to conduct the tests and surveys.
Things to keep in mind while digging a bore well:
Conventional modes of identifying potential sites of bore wells such as using wooden sticks and magnetic blocks are successful to an extent. But these methods may not always be successful based on the geological formation which is a critical factor in identifying bore well sites. There are other more expensive modes of geophysical surveys that can also be used.
Summer months are generally the most preferred time to dig bore wells as the location can be accessed freely without the hindrance of naturally occurring factors such as snow, rains etc. there is however no prescribed time for drilling the bore wells. If the site location is appropriate and levels of ground water available are satisfactory to the digger, the bore well can be dug up as needed.
Almost all agricultural can be accessed by drilling rigs only in the summer months due to their availability in this season. Thus identifying a suitable bore well site and drilling the bore well in summer months will give the best possible scenario and numerous advantages to the location at that time.
Bore wells that are dug up for domestic purposes are generally limited between 4.5- 6 inches diameter. 6 inches bore wells are drilled when the yield that is required is high, generally for large apartments, commercial buildings or small agricultural practices.
The large diameter bits are initially used to place casting pipes o the hard rock zone prior to drilling specified size of the bore well.
There are various charges that may have to be incurred during the process of setting up a bore well. The most common of these are drilling costs, cost of casting pipes, cost of drilling and instillation charges, flushing costs and transportation costs.