How Deep Should A Well Be For Drinking Water?

by Jay | Updated on October 22nd, 2022

Although many variables affect this, drinking water wells generally need to be at least 100 feet deep to prevent surface contaminants from getting inside the well. 

If your location’s geology differs from that of another area of the country, you might need a more deep or shallower well. The kind of your soil and the presence of rocks in the earth will affect how deep your well is. Because some stones are impenetrable, the well will need to be bored deeper.

Large drilling machine, well drilling

The depth of your well must also be sufficient for you to draw water even when the water table is low. 

A well is a location where you can retrieve potable water. You may make wells by drilling through bedrock or similar hard surface or digging in the ground using manual equipment like shovels and hand drills. 

Wells are crucial because they can supply people with water when there may be no other options, such as during a natural disaster or if the public water supply becomes contaminated. Because they provide a reliable drinking water source independent of local infrastructure, wells are most frequently used in rural locations.

Additionally, farmers utilize them to irrigate feedlots for animals and crops. 

How to find out the proper depth in your area?

Old brick and concrete deep well

The best well depth for drinking water in your area might be something you’re interested in finding out. Getting some firsthand experience is an excellent method to learn more about this.

Talk to your neighbors or expert drillers to find out at what depth the water is safe to drink. The neighbors can provide precise information because they may have dealt with the issue of unclean water from shallow wells and dug further to obtain better-quality water. 

Surface contamination risks 

In terms of the subsurface water table, deeper wells face significantly less risk than shallower wells. Wells are constructed correctly with a suitable casing, and well caps shield water from impurities, including dirt, heavy metals, and microbes.

A shallow well’s water is likely unfit for drinking if it is situated next to an agricultural area or in the path of runoff water from rain. 

Fertilizers, insecticides, herbicides, pesticides, surface contaminants, dust, dirt, and other contaminants will contaminate the water. Because it will be challenging for pollutants to get there, a  deep well will have relatively less contamination. 

Well surrounding 

You can drink water from a shallow well if the environment is tidy and clean. Verify that no nearby livestock feedlots could contaminate the shallow wells. 

The volume of underground water

A well won’t be used just for drinking. It will also be used for other needs, such as bathing, cleaning dishes and clothes, gardening, and other things. The well must be deep enough to access a superior water potential with greater volume. For more information, confirm geological surveys and consult specialists.

Well Casing, Well Screens, and Well Caps

Installing a high-quality, properly-sized well casing is necessary to ensure water quality. The optimal well casing for a 100-foot-deep well has a 3-foot-tall mesh screen where water enters the hole before being pumped. 

It is crucial to install a high-quality well screen since it is the primary barrier between dirt and water. No matter how deep the well is, the water quality will decrease if there are streams in the excellent casing. A good cover is required to ensure that no environmental toxins reach the well. 

Seasonal rise and fall of the water table 

Due to local groundwater consumption and seasonal precipitation in the area, the water table in the well will rise and fall over the year. As a result, the well needs to be dug further than the water table’s lowest predicted elevation. Water levels may fluctuate over many years if there has been a drought. 

Therefore, it can be helpful to know the lowest point in the range of water levels across multiple years. 

Fresh water from a well flows out into an old bucket. Shallow depth of field for focus on water.

Low-yielding rock formations

The well may need to be bored deeply enough to act as a cavity for groundwater storage in low-yielding rock formations. The amount of water that can be held inside a suitable hole depends on the well’s overall depth, the distance from the top of the groundwater table (static level), and the diameter.

For a given well depth and water table height, a more considerable well depth, and water table height, a larger well diameter will be able to hold more water. Subtract the depth from the static water level from the well’s drilled depth to determine the “thickness” of the water stored there.

Building codes

The local health department does not keep an eye on the quality of private water. Water testing is up to you, but building codes are created to safeguard the drinking water supply in your region.

They established minimum good depth and pump installation standards using data on the water table. Contractors have a rough idea of how deep your well has to be before drilling starts, and that information helps them decide what kind of well you need. 

Frequently asked questions

How much does drilling water well cost?

The art of drilling wells is not perfect. Business bill by the linear foot, and the deeper the well, the more expensive it is. A hand-dug well could cost as little as $2,000, but deep drilling can cost up to $15,000, not including the casing and pump.

How do I know how deep my well is?

As you move past the pump, your body can feel a bounce. As you pass, remember that this may change from case to case. 

Mark the top edge of the casing with your thumb.

Pull out for a moment, then gauge the depth of your well. This is how far down you are from the drill hole. 

Is it better to have a deep or shallow well?

If your land can accommodate a shallow well, both the budget and the needs may be satisfied. Deep wells can be less expensive than conventional ones, despite being a better option for people suffering from drought and pollution. Your property might be an excellent location for shallow wells because you wouldn’t have to spend as much money there.


It is best to ensure the excellent depth is at least 100 feet if you rely on a private well for your potable water supply. This will shield against surface contaminants like motor oil, insecticides, or fertilizers. 

A shallow well should be regularly watched for changes in taste or odor because it may be prone to these contaminants.

Water should always be accessible because we all need it to survive. The benefits of drilling a well for drinking water are numerous. Use a whole house water filter for your well water as well.


Jay is a health and wellness enthusiast with expertise in water quality and nutrition. As a knowledgeable advocate for holistic well-being, Jay successfully manages Type 2 Diabetes through informed lifestyle choices. Committed to sharing reliable and authoritative insights, Jay combines firsthand experience with a passion for enhancing health."