Many people do not have the idea that water can be complex. There are various types that are available today. Sometimes, you can get overwhelmed and confused about what is the best type to use for the family.
One of the controversial water today is the artesian water. Know more about it in this article.
What is Artesian Water?
The term artesian is from a province in France named Artois. In this place, it is stated that water wells were first used. Thus, it is a term used for the natural phenomenon.
Artesian water is the confined natural underground reservoir that contains water under positive pressure. The aquifer is the geologic layer of rocks or limestone that provides as the source of the artesian well.
Such aquifers are commonly found underneath the surface of the earth. This is where the preserve deposits and massive amounts of the finest water.
The majority of the artesian aquifers around the world are replenished non-stop by the groundwater and the rain. The water flows down from the porous substances. Examples of which are the gravel, rock, and sand. Around these porous substances are rock or other hard materials. As such, the water cannot escape and reach the ground level.
In general, the artesian groundwater is similar to any type of groundwater in your property. The difference is with regard to the process of how it gets to the surface.
The artesian well does not need a pump to push the water into the surface. This is because there is so much pressure in the aquifer. It pushes the water out without any assistance.
How are Artesian Wells Formed?
Artesian wells are formed when water flows down a land decrease into a porous rock substance like limestone, sand, or gravel. This alone wouldn't push water upwards, however when the porous ground is enclosed by a layer of dense rock— the water source encounters critical pressure. This pressure powers the water upwards where it's delivered into a well and looks like a fountain (sans steam).
A portion of these artesian wells are solid to such an extent that they can give enough water pressure to multi-storied buildings!
So as to make an artesian well, you just need to take advantage of the source – truly. Therefore, drilling companies around the globe have made artesian wells to access this novel sort of spring water.
Artesian Well VS Flowing Artesian Well
The artesian well connects into the confined aquifer. With this, the well water will rise on top of the aquifer. However, it will not reach the land surface.
Meanwhile, the flowing artesian well is a type of well that has been drilled into an aquifer. The pressure that is present on the aquifer will force the water underneath to rise above the land naturally even without the use of a pump.
It can flow on a continuous or intermittent basis. It can originate from the aquifers which occur from unconsolidated materials. Examples of which are the gravels, sand, or bedrock. The depths range from a few meters to thousand meters. Take note that all flowing wells can be considered as artesian wells. However, not all artesian wells are known as flowing wells.
The Reason of Why Wells Flow
There can be two types of situations why the flowing artesian wells are found. These are the following:
- The aquifer is restricted by impermeable materials. Examples of which are the confined beds where the static water level is on top of the aquifer plus the surface of the land.
- There is no confinement on the aquifer. However, the static water level is above the surface of the land.
The conditions of the artesian water can be generated through various factors such as the topographical and geological controls.
With the geological controls, the water will rise above the ground due to the pressure restricted in the aquifer. If you drill a well from the surface of the land via the impervious layer, the pressure will lead to the rising of the water. As such, it will cause the flow of the artesian well especially in areas where the pressure is great.
Whereas in topographical control cases, the hydraulic head is higher versus the surface of the land. Usually, this occurs at discharge areas at lower elevations which are found near the lakes and rivers around steep slopes.
With depth, the pressure of the groundwater increases especially in the discharge areas where it is controlled by the topography.
The Importance of Controlling or Stopping the Artesian Flow
Learning to control or stop the artesian wells will prevent the wastage of the groundwater. For example, if an artesian well is uncontrolled and it flows at 10 USgpm, it can waste around 14,400 gallons of water every day. Each year, it can waste around 5.25 million gallons of water. This is enough to supply four homes already.
Wasting water may decrease the confining pressure available in the aquifer. The well will no longer flow at a reduced rate and affect the springs and wells near it.
Whenever the groundwater breaks outside the well, it can possibly cause flooding, sinkhole, and damage to the area. One reason to control its flow is to prevent the groundwater from the aquifer to overlying aquifers. If the situation is not contained, the clay, gravel, silt, sand, and other fluids can possibly carry the artesian groundwater to the surface water. As such, the surface water’s quality will be affected.
Moreover, the flowing artesian wells can lead to erosion. The accumulated flowing water in the ponds can contribute to mosquito problems.
Determining the Artesian Conditions before Beginning to Drill
Before drilling a well, it is crucial to do a pre-drilling assessment. This will determine the range of the flow and the pressure which can be found during the drilling. With this, you can know if there are instances of flowing artesian condition which you can possibly encounter.
The pre-drilling activities include determining geological conditions, gathering information, knowing the static water levels, and any history of the artesian water in the area. You can obtain this information from the following:
- Checking the reports available from the local well constructions
- Reviewing the available hydrological reports
- Interview with the government’s environmental hydrogeologists
- Consultation with the professional hydrogeologists and drillers within the local area
If such information is currently unavailable, the person-in-charge of drilling the well must consider the proposed depth of the well in accordance with the geological and topographical information of the site.
Also, the electrical survey or the geophysical logs can be used to have a better understanding of the subsurface conditions.
Whenever there is limited information available, it is best to take some precautionary approaches to the issue. Planning should be considered seriously, and one should assume that the flowing artesian conditions are always present.
- control the flow
- secure the casing or borehole
- ensure the drill rig
- expanding the weight of the drilling mud
- using plugs
- using a surge-blocking to limit flow
- introducing a drillable packer.
Controlling the Artesian Flow from the Well
One can say that the flowing artesian well is under control when the entire flow is through the production casing up to the wellhead. Thereafter, one can stop the flow indefinitely without surface leakage on the ground’s surface. This can also prevent leakage into other aquifers near the well.
If the flow of the artesian well is controlled, it will not stop the flow or even dry up the well. This is true especially if the well is constructed properly.
As a matter of fact, the opposite is true since the waste of the artesian water will cause a decrease in the artesian pressure. If you control the flow of the artesian well, it will prevent the unnecessary loss of the groundwater which comes from the aquifer.
Why Choose Artesian Water?
Nowadays, more people are considering the importance of drinking artesian water. The water is from the deep aquifers of the country. It reaches the land as it falls through the rocks and mountains for decades. As such, the water has a rich concentration of natural minerals. It is also considered to be free from contaminants. With this, many people choose the artesian water. This is true when they decide on safe and healthy bottled water for their family.
Now, here are the benefits of drinking artesian water:
Contains Natural Minerals
The artesian water is the type of water that the human body is designed to consume. It contains natural minerals that are just right for our health. Some of the minerals are:
- Calcium- Calcium is known as essential for life. It is crucial for building and maintaining bones. It prevents blood clots and makes the body healthy. It makes our muscles contract and our heart beating. 99% of the calcium in our body is found in our teeth and bones.
- Fluoride- The artesian water has been proven to have traces of fluoride on it. Fluoride is beneficial to cause good dental health. However, the content is not as high as that in the tap water. As such, you must not worry about the potential health hazard the artesian water can cause to consumers.
- Electrolytes- Artesian water contains natural electrolytes. With this, it is beneficial in regulating the pH balance of the blood. The bicarbonate found in the electrolytes can regulate the pH levels of the blood. It avoids the blood from becoming too acidic and prevents you from feeling too tired.
Indeed, the artesian spring water has various benefits. Its awesome natural taste can make it one of the best alternatives for soda and other sugar-based drinks.
Always Opt for Genuine Artesian Water
It is best to opt for companies that use natural artesian water, whether for your office or home use. Choose companies that use water from the springs and bottle it directly. There are also suppliers that deliver water bottles using certified food-grade material.
Water Quality Concerns of Flowing Artesian Wells
In sum, the quality of the flowing artesian wells is excellent. But in some cases, there are artesian waters that have poor quality. It can cause a serious issue on the overlying aquifer plus the surface water.
The quality of the water can be affected by the depth of the well. For example, if artesian water is deeper flowing, it can have poor water quality versus shallower flowing well. The water from the bedrock formations like the deep sandstone formations can have arsenic content on them. This can lead to serious health problems in the long run. Thus, those artesian wells with poor water quality must be closed permanently.
Meanwhile, the majority of the problems with flowing artesian wells are due to improper construction of the well or improper discharge controls. For example, the corrosion of the casing plus leakage is possible due to the constant flow of the water. This is true if the water contains fine sand or if it is corrosive.
If the artesian water is corrosive, a pipe that is smaller in diameter can be installed in the well. This pipe can be made of corrosion-resistant material. It can be replaced periodically when it becomes corroded. Remember not to use the thin-wall casing when it comes to artesian wells.
Failure of the surface seal or the casing during construction can be costly. It can even result in the eruption of a large amount of sand, silt, clay, or gravel. It can cause unstable conditions and potential flooding to nearby structures. This is possible through subsidence and erosion which can harm the living area of the aquatic organisms.
The screens of the well can yield water withstand if it is not developed properly. This can be an issue if the flowing artesian well in an aquifer is shut-off. Then, the sand will clog and settle in the area and beneath the casing. As such, the screen size should be coarse to prevent the buildup of pressure in the aquifer. It must be noted as well that the well should be developed properly.
Experts do not recommend the use of the perforated casing in artesian wells. In some instances, the smell of an unpleasant rotten egg is present. This can be controlled by stopping or reducing the flow of the artesian wells.
Hygiene in Relation to Geology
Selection of the Site
Before beginning the drilling, you must choose a good site. In the majority of the cases, the owner or the villagers will point you to the location which is suitable for the wells. However, this might not be the best location to get the best quality of water. Thus, you have the responsibility to get to know about the hygiene of the water and the most hygienic location for the well.
Indeed, there are two important factors that you have to take note of.
First, consider the presence of sources of pollution which are the waste dump areas, fuel stations, toilets, and fireplaces. Second, consider the shade or son of the location of the well.
Some homeowners might find it practical to build their well near to their house and latrine. But when you do so, you might not realize that the well is close to toilet which will cause contamination of microorganisms like viruses, bacteria, and parasites.
These organisms can cause illnesses like diarrhea whenever it is consumed. The pathogens found from the human wastes in the latrines can move downwards and contaminate the groundwater.
Thus, in the selection of the good site for the well, it is best to construct the well which is down-hill or down-stream from a latrine. If you find it difficult to determine the flow of the groundwater, build the well 30 meters away from the latrine.
Waste Areas, Fire Place, Fuel Stations, and Farms
The same principle applies to areas where wastes are dumped or burned. Or where fuel plus other contaminants can seep into the groundwater which can lead to contamination. Chemicals found in the drinking water can lead to serious health problems such as failure of bodily functions.
Sun or Shade
Drillers may tell you than they like to drill under a shade. But this is not a good location for a well. Many people will go to the well to fetch some water. But they are unaware that they are carriers of harmful pathogens from the soles of their feet.
For example, the bacteria can be picked from work or even from the latrine, especially if someone just went to the toilet. These contaminants will be washed off from your feet and into the well surrounding. These are considered as a threat to the quality of the water. Whenever a well is placed under a shade, algae and bacteria will thrive. But if the well surroundings can dry up each day, the sunlight will disinfect the area and kill the pathogens.
Migration of Pathogens
Pathogens which include viruses, parasites, and bacteria will move downward with the infiltrating rainwater through the permeable soil layers. When it is now in the groundwater, the chemicals and pathogens will spread horizontally and vertically deeper into the aquifer.
The groundwater will easily flow through the permeable layers like gravel and sand. Chemicals and pathogens which are dissolved and suspended in this groundwater will migrate through permeable layers.
Water with pathogens must be stopped before it reaches the surroundings of the well-screen. Luckily, impermeable layers can be found. Water and the pathogens do not flow well with these impermeable layers. Because of its fine texture, the impermeable layers prevent the pathogens from vertical migration down into the aquifer. Since the impermeable layer blocks the pathogens from downward migration, the lower aquifer is the one that contains the water without the harmful chemicals and pathogens from the surface.
But sometimes, only one aquifer exists within the reach of manual drilling equipment. For example, a 50-meter thick permeable sand layer.
Yes, there is no impermeable layer in this case. But down into the sand layer, the number of pathogens will decrease little by little. It takes time for the pathogens to go down and as they do so, they will die over time.
But there is no impermeable layer which will prevent the downward movement of contaminants and pathogens. This will mark the exact depth of which the contaminants are not present anymore. Thus, it is recommended to drill as deep as possible in places where only one aquifer is existing.
By drilling through the impermeable layer, there is a short cut created between the first and second aquifer. As you drill a hole into the impermeable layer, it will enable the contaminants to flow down from the polluted layer into the clean aquifer and well-screen.
When a hole is drilled, a well-screen and gravel pack will be placed. Thereafter, the impermeable layer has to be closed. This will prevent the contaminants from traveling down into the second aquifer. This is possible with a sanitary seal. This is a seal that is made of bentonite and cement which will now seal again the impermeable layer.
Whenever there is only one aquifer, a sanitary seal which is 3-5 meters thick must be installed above the gravel pack. This will prevent the contaminants from entering the well-screen. Pathogens and water can travel faster down into the loose material in the borehole than through the undisturbed soil. This will force the water to flow through the normal undisturbed soil. Then, it will increase the traveling time from the surface water and into the filter screen.
Water Quality Testing
Good quality potable water is free from disease-causing bacteria and excessive amounts of chemicals. The smell and taste of the water should be clear. To make sure that the water quality is suitable for drinking, the water must be tested.
Indeed, drinking water must be tested based on various parameters:
- Chemical parameters: hardness, pH level, electrical conductivity, heavy metals, iron, nutrients, artificial threats, and natural chemicals.
- Biological parameters: Pathogens, parasites, and viruses.
- Physical parameters: Color, turbidity, color, smell, etc.
Most of the water quality tests must be done in a laboratory. However, some tests can also be done in the field.
When taking water samples for testing, make sure to wait until the whole process is finished. Wait for another few weeks to allow some parameters to disperse. Do not take a sample immediately after well disinfection. This will make the result predictable but not useful in the study.
After the construction of the well is completed, make sure to disinfect it to kill the harmful organisms. The pathogens might have entered the well during the annular backfill or the installation process. Disinfect the well by chlorination.
Key Issues to Take Note When Drilling a Flowing Artesian Well
It is challenging to construct flowing artesian wells with high flow rates and pressure. Those flowing wells that are drilled deep in the ground are less prone to developing flow problems. They are easier to deal with. In bedrock locations, the rock allows for the easy installation of the seal.
If you drill a well into a confined aquifer, you can potentially disturb the overlying geologic layer which provides a potential pathway to the pressurized movement of the artesian water. As such, the close the above portion of the artesian formation is to the surface of the ground, the more challenging it is to control the flow.
As such, it is best for the qualified well drillers to observe the condition of the flowing artesian water. Do this for one to two weeks after the construction. Check if there are any leakages outside or in between the casings.
Disinfecting the Artesian Wells
In general, the flowing wells are less prone to bacterial contamination due to the protected nature of the artesian aquifer. Also, the positive artesian pressure can minimize the entry of the contaminants into the well. The contaminants introduced at the process of drilling can be flushed out via continuous discharge of the water.
To disinfect the flowing well with the use of the chlorine, you can put a temporary casing extension above the piezometric level. This can increase the chlorine and stop the flow. If the chlorine solution can potentially harm the environment, then you can use a neutralizing agent. Examples of which is Vitamin C. This can inactivate chlorine, and it is affordable. The reaction time of the Vitamin C is also instantaneous.
In case that the chlorinated water can possibly harm the environment such as fish, use a powerful killing agent like Vitamin C, to inactivate the chlorine. A solution of at any rate 1 percent (by weight) of ascorbic acid is the most savvy type of Vitamin C. Added to the sump or a stream of chlorinated water, reaction time is almost prompt.