“Artesian” is a term used loosely to describe water that comes from deep underground.
You may have seen artesian bottled water on the shelves and wondered what artesian water is exactly, and what makes it worth the extra cost.
Manufacturers claim that it’s healthier because it’s “naturally filtered,” but the truth is, it’s not much different than most groundwater. Still, there’s more to artesian water than meets the eye.
- Artesian water is water that is tapped from a deep well and flows to the surface naturally, as opposed to being pumped up.
- It originates from an aquifer, which is a layer of underground rock or sand saturated with water.
- Artesian water is often purer than surface water because it has been filtered naturally by the underground layers, and it has fewer pollutants.
- The water pressure from deep inside the earth pushes the water to flow up through the well without requiring a pump.
- Two of the largest Artesian wells in the US can be found in Georgia and Florida and are found in many parts of the world.
What is Artesian Water?
Artesian water is groundwater stored in a confined aquifer. Trapped between layers of impermeable rock, it’s effectively pressurized and will rise without a pump if given an opening. Known as artesian pressure, this is the natural pressure puts the “spring” in spring water.
The term artesian comes from the free-flowing wells that once served the Roman city of Artesium in the Middle Ages, but artesian aquifers are found all over the world. Georgia and Florida are home to two of the largest in the United States.
How Are Artesian Wells Formed?
Rain creates artesian aquifers in the same way that rivers carve canyons. Over time, water flowing through the soil can erode the bedrock, creating a confined, natural underground reservoir in which water collects. Artesian wells are formed when this water rises to the surface.
Is Residential Well Water Artesian Water?
Not all aquifers are confined. Many deep residential wells are drilled into unconfined aquifers deep within the water table. Only wells that tap artesian water are known as artesian wells. There are two different types based on how high the water rises once the aquifer is tapped — artesian wells and flowing artesian wells.
Artesian Wells Versus Flowing Artesian Wells
All artesian aquifers generate positive pressure, but some don’t have enough natural pressure to drive water all the way up to the Earth’s surface — they require a pump. Known simply as an artesian well, this is the most common type of drilled residential well.
A flowing artesian well or natural artesian spring is one that taps a high-pressure, confined aquifer. Water rises to the Earth’s surface naturally with no pump needed.
Popular for agricultural purposes, flowing artesian wells are drilled to water crops and feed livestock. Special permits are required to ensure they’re properly constructed to minimize soil erosion and wasted groundwater. A flowing artesian well with a flow rate of 10 gallons per minute could waste more than 5 million gallons annually.
How Deep Are Artesian Wells?
Only Mother Nature decides how deep artesian wells can be — there’s no upper or lower limit. But practically speaking, most are hundreds of feet deep with wells in some areas exceeding 1000 feet or more. Australia has the largest known artesian aquifer in the world. Known as the Great Artesian Basin, it reaches depths of nearly 10,000 feet.
Is Drinking Artesian Water Safe?
Like all groundwater, artesian water quality varies. But claims that it harbors fewer contaminants than surface water have some validity. Soil is a natural water filtration system, so water is purified as it flows through the permeable layers of rock into deep aquifers. And some confined aquifers are surrounded by such impermeable rock that contaminants can’t enter at all. We can’t, however, drink from an artesian aquifer with a straw.
Untreated artesian spring water that bubbles to the land surface could contain a witch’s brew of contaminants from the surrounding soil. Water from a drilled artesian well is usually safer than water from springs and shallow wells.
Still, all groundwater is vulnerable to contamination from the very rock it sits in, no matter how clean it may otherwise be. Artesian well water can be free of bacteria and chemicals yet laden with arsenic. And artesian spring water commonly contains sulfur — the mineral that makes drinking water smell like rotten eggs.
As long as there’s potential for poor water quality, artesian water should be tested annually like any other well water and treated if necessary.
Is Bottled Artesian Water Safer?
It’s no secret that many brands of bottled water are nothing more than filtered tap water. But because bottled water is treated, it’s a better bet than unfiltered spring water.
Is it safer than your municipal drinking water supply? Probably not. Your city water source is regularly tested and treated for nearly a hundred common contaminants, including biological pathogens.
Artesian water does, however, have a higher mineral content than most tap water. Natural minerals buffer off-tastes, so artesian bottled water may taste better than regular bottled water.
The Pros and Cons of Artesian Wells
If you’re building a new home and need a well, drilling deep into an artesian aquifer has advantages and disadvantages.
Artesian Wells Rarely Run Dry
Because artesian wells tap water far below the Earth’s surface, they’re less vulnerable to seasonal fluctuations in the water table. Neither drought nor floods will affect the flow rate of your well nor introduce any weather-related contaminants, so you’ll never run out of clean drinking water.
Add they Have a Brisk Flow Rate
Residential wells are notorious for low water pressure. Drilling into a confined aquifer reduces artesian pressure, but because artesian wells produce massive amounts of water, the flow rate and pressure are comparable to city water.
Artesian wells require special equipment to dig. The cost of renting a drill rig that can power through dense rock can break the bank. And in most cases, you’ll still need a pump to bring water to the surface.
The price of an artesian well can be double that of a dug well. Still, if you have a low water table, it’s a good investment if you can afford it.
Testing Artesian Water
Whether it’s well or artesian bottled water, the only way to know what’s in it is to test it. If you drink city water, your annual water quality report tells you where your drinking water comes from — ground or surface water — and the levels of problematic contaminants.
But if you drink from a well, doing a water test is up to you. The Centers for Disease Control and Prevention recommends testing private residential water annually for:
- Total dissolved solids
- Coliform bacteria
Testing artesian water is straightforward. You can bring water to a lab or purchase a home test kit. Test strips are available for as little as $15, but we recommend a comprehensive approach if it’s been a while since your water has been analyzed. We like SimpleLab’s TapScore test kits.
They offer panels for city, well and even bottled water. If you’ve always wanted to know what’s in your favorite brand without taking the manufacturer’s word for it, now there’s an easy way to find out.
Testing artesian well water is particularly important because it likely has nuisance contaminants, such as sediment, that you’ll want to filter out. Knowledge is power when it comes to water safety and choosing filtration equipment.
Filtering Artesian Water
It’s a rare artesian well that doesn’t benefit from some type of filtration. Confined aquifers often contain sulfur compounds. And once water reaches the top of the aquifer, it’s likely to pick up sediment and other ground contaminants that may affect your water quality.
The above-average mineral content in artesian water can cause limescale build-up in your plumbing system — a costly problem you can solve with a water softener or TAC water conditioner. Filtration may protect your home and make artesian water taste better.
Artesian water is one of Mother Nature’s many gifts. So, have a drink and celebrate one of the most unique geological features on the planet we call home.