- The type of well you choose to install depends on factors such as regional geology, water table depth, budget, and required water quality.
- There are three main types of wells: dug, driven, and drilled.
- Dug wells are shallow, and typically lined with stones to prevent collapse.
- Drilled wells, are very deep and access underground aquifers.
- Driven wells reach shallow aquifers, usually in areas with shallow water tables.
Wells have been a crucial source of water throughout history, providing access to essential water resources for agriculture, industry, and daily consumption.
There are three main types of wells: dug, drilled, and driven wells. Dug wells are shallow, and typically lined with stones to prevent collapse. Drilled wells are very deep and access underground aquifers. Driven wells reach shallow aquifers, usually in areas with shallow water tables.
After extensively researching welly types and installations, we will provide useful information and guidance to help you understand the advantages, disadvantages, and specific considerations for each type of well. This will equip you with the necessary tools to make an informed decision when selecting a well that suits your requirements and local geological conditions.
Types of Wells
There are various types of wells, with each being designed for specific needs and environments.
Well depths for drinking water vary based on factors such as soil type and local regulations, but a drinking well should be a minimum of 100 feet below the ground surface or 10 feet below the water table.
For all other uses, shallow wells are acceptable options. If the shallow wells have been properly fitted and covered, they should also be safe for drinking water. Let’s take a closer look at five common types of wells in more detail.
1. Dug Wells
Dug wells are shallow, man-made wells that are excavated by hand or with machinery.
These are often found in areas with soft or less-permeable materials like silt, sand, or clay, and are usually lined with bricks, stones, tiles, or other materials to prevent collapse.
Dug wells are typically capped with stone, concrete, or wood to protect the water source from contaminants. In the past, these were hand dug wells that were less complicated to install.
The main appeal of opting for a dug well is the relatively quick and easy installation.
This is a low-tech solution for accessing groundwater and you can do so with a small budget and fewer labor requirements.
Dug wells are not very reliable as a long-term groundwater source. Given that dug wells are usually only 30 ft deep, they are much more susceptible to contamination.
Who Should Install a Dug Well?
If you want to install a well on a budget and are looking for a quick solution to access groundwater, dug wells are a solid option to consider.
If you can take measures to prevent contamination, dug wells are very easy and affordable compared to more advanced well options.
2. Driven Wells
Another type of well is the driven well. These wells are constructed by driving a pipe into the ground, and they are often used in areas with shallow water sources.
Driven wells are comparatively cheaper to construct and can also be pulled out and moved, unlike dug or drilled wells.
A key selling point of driven wells is that they can be easily moved and relocated.
Installing a driven well is pretty simple and does not require a large diameter, provided that your ground materials are suitable for this type of well.
A major problem with driven wells is that they cannot be installed in every location. The ground material around your well needs to be quite soft such as fine sand, dirt, or clay (in most cases). You cannot install a driven well if your ground is made out of solid rock and only shallow water can be accessed with this method (30 to 50 ft deep).
Who Should Install a Driven Well?
If you want to install a well on a budget and have a soft ground material on your property, a driven well is an ideal choice.
You should also consider installing a driven well if you want to move the location of your well later on, as they are easy to relocate given the small diameter pipe.
3. Drilled Wells
Drilled wells are the most common and deepest type of well. They are constructed with either cable tools (percussion) or rotary-drilling machines and can be more than 1,000 feet deep.
If this type of well needs to be drilled through unconsolidated materials, requiring the installation of a casing and a screen to prevent the inflow of sediment and collapse.
The best thing about installing a drilled well on your property is that you can count on it for decades.
Given how deep drilled wells are dug, they tend to have a lifespan of at least 30 to 50 years.
Despite their longevity, drill wells need to be approached with caution.
This is mainly due to them accessing deeper groundwater that may contain sediments from harmful minerals such as arsenic and fluoride.
Who Should Install a Drill Well?
If you want your well to provide water for decades, you should opt for a drill well.
In addition, if the water source you are trying to reach is below 30 to 45 ft and the ground material is hard rock, a drill well may b your only option.
4. Artesian Wells
Artesian wells are a type of drilled well that taps into pressurized water sources beneath the ground at about 200 to 500 ft deep.
They access water from water-bearing layers called aquifers, which are under pressure due to their natural geology.
When flowing artesian wells are drilled, the water rises to the surface without the need for a pump, as the pressure from the aquifer forces the water upwards.
Artesian wells are generally self-pressurized. This implies that you do not need to install a water pump in most cases.
They also require less maintenance over the years, making them a relatively hassle-free solution for accessing groundwater.
The constant pressure that comes with Artesian wells can prove to be unreliable in some cases. It’s quite common for the natural pressure that comes with these wells to be inconsistent, resulting in fluctuating pressure changes.
This can be particularly problematic if the pressure becomes too high, as this can potentially damage the pipes and plumbing in your home.
Who Should Install an Artesian Well?
If you’ve tested the pressure of the well and have installed quality plumbing, an Artesian well is very reliable.
This is another great well option if the aquifer you need to tap into is quite deep, as most Artesian wells are dug between 200 and 500 ft.
5. Interceptor Wells
Interceptor wells are used to prevent contamination of underground water resources from nearby industries or other sources of pollution.
These wells are strategically placed to intercept contaminants before they reach a water supply, ensuring the quality of the water remains high.
If you are concerned about contaminants making contact with your water source or soil, an interceptor well offers exceptional defense to prevent pollution.
Installation needs to be handled properly to ensure the well does its job properly in case of contamination. This often requires costly and expert-level installation.
Who Should Install an Interceptor Well?
This kind of installation only makes sense if you have a legitimate concern about pollutants contaminating your natural resources such as water and soil.
Well Construction Techniques
Hand digging is one of the most traditional and oldest methods of constructing wells. Shovels and other simple tools are used to dig a hole into the ground until a water source is reached.
This technique is more suitable for shallow wells, usually around 10 to 30 feet deep, as it is labor-intensive and can become dangerous at greater depths.
Drilling is a modern method of well construction, which uses specialized drilling machines to penetrate the earth's surface.
There are various drilling techniques, including rotary, reverse rotary, air rotary, and cable tools.
Drilled wells can reach depths of more than 1,000 feet, providing access to deeper water sources.
When drilling through unconsolidated material, it is necessary to install casing and screens to prevent sediment inflow and collapse of the well.
Chemical techniques are utilized for constructing wells in specific contexts, such as for water wells in karst terrain, or for deep wells in sedimentary formations.
Such methods may involve the use of chemicals or explosives to break up and dissolve rock formations, allowing easier access to underground water sources.
Due to the specialized nature of these techniques and potential environmental risks, their application is typically limited to specific situations and under the supervision of experienced professionals.
Well Maintenance and Protection
Maintaining and protecting your well is essential to ensure a reliable water supply and to protect your family's health. In this section, we will discuss well inspection, water quality testing, and wellhead protection strategies.
It is crucial to inspect your well annually for mechanical problems and cleanliness to prevent issues that may compromise water quality.
A professional well contractor should assess the well's components, such as the well casing, well cap, and pump system. This ensures that any necessary repairs or replacements are conducted to maintain proper functionality.
During inspections, pay close attention to the following signs:
- Structural Damage
Additionally, ensure the well cap is secure and watertight, preventing contaminants from entering the well. If issues are detected, it is vital to address them promptly to prevent further deterioration.
Water Quality Testing
Testing the water quality annually is essential to ensure the safety of your drinking water. You can choose to either test your water at home or send a sample to a lab for a more thorough analysis.
At-Home Well Water Testing Kit
I personally recommend testing your well water at home at least once per year to ensure that it’s safe to drink and free of contaminants. Buying a well water testing kit is relatively affordable and easy to use.
If you find any sings of serious contamination in your well, you should report this to your local health department.
A state-accredited testing laboratory should analyze your well water for total coliform bacteria, E. coli bacteria, nitrates, nitrites, and any other local contaminants, such as arsenic or radon.
Regular testing helps detect contaminants before they pose health risks and provides an opportunity to address any water quality issues.
In case of contamination, consult a well professional to identify the source and implement appropriate treatment solutions. You should aim to have your well water lab tested at least every 3 to 5 years (preferably annually).
Protecting the wellhead and surrounding area is crucial to prevent contaminants from entering your well.
Keep the area around your well clean and clear of debris, chemicals, and other potential pollutants. Be mindful of activities and land uses near your well that might affect water quality, such as septic systems, agricultural activities, or industrial operations.
Ensure a safe distance between your well and any potential sources of contamination. Properly maintaining and regularly inspecting your well can also contribute to wellhead protection, by identifying and addressing issues before they affect water quality.
By following these guidelines on well inspection, water quality testing, and wellhead protection, you can help ensure the safety and reliability of your well water supply for years to come.
When discussing types of wells, it's essential to consider their environmental impact. In this section, we’ll focus on two critical sub-topics: Groundwater Conservation and Contamination Prevention.
Groundwater is a valuable natural resource, providing drinking water and supporting agriculture. As a result, it's crucial to manage it sustainably when constructing and maintaining wells.
While dug wells are usually shallow, drilled and driven wells can reach depths of more than 1,000 feet, impacting the overall water table in various ways.
To conserve groundwater, the proper siting and design of wells are imperative. Also, periodic maintenance checks and reducing wastage help to maintain groundwater levels.
Preventing contamination is important for both the environment and the health of individuals who rely on well water. Wells can become contaminated by heavy metals, pollutants, and other substances.
Proper well construction plays a significant role in preventing contamination. The casing material helps to protect the well from surface water. Additionally, sealing the space around the casing with grouting material, such as cement or bentonite clay, prevents water from seeping in from the surface.
A screened well point and a proper filtration system will also do wonders at preventing contaminants and sediments from sabotaging your water,
Property owners can also take steps to minimize the risk of contamination. Ensuring proper waste disposal, avoiding chemical storage near wells, and testing water quality regularly are just a few ways to keep well water safe and clean for consumption.
About THE AUTHOR
I have over a decade of experience in food and beverage management, including a ServSafe food safety qualification. As part of this qualification, I have been professionally trained in safe food storage.Read More About Mark Walker