What Is Artesian Water?

How It's Different and Why It Matters

Artesian water is a natural source of groundwater contained under pressure within a confined underground layer of rock or sediment called an aquifer. Because it is trapped between impermeable layers, the pressure forces it upward to the surface through a well or natural opening like a spring, without any pumping required.

Believe it or not, that's the simple answer. But what really makes artesian water special is everything that goes on underground, so in this article, we’re going to explain our water on a deeper level: the geology that protects it, pressurizes it, and shapes its mineral content long before it ever reaches your table.

How Is Artesian Water Made?

Artesian water starts as natural, abundant rain and snowmelt, which sinks into the ground at a high-elevation recharge zone like a mountain range, or hillside.

From there the water slowly travels downward, sometimes for over hundreds or thousands of years, filtering through layers of sand, gravel, and rock. Over time the water gets trapped between two impermeable layers like clay or dense rock (granite in our case), and forms a sealed underground reservoir called an artesian aquifer.

Because the recharge zone is higher in elevation than the well or opening, gravity creates natural hydraulic pressure. So when an opening is made, through drilling for example, the water rises on its own. In some cases, it shoots to the surface. That's a flowing artesian well: no pump, no mechanical assistance, just natural pressure doing the work.

What is a “Confined” Aquifer?

A regular (unconfined) aquifer sits below the water table and is open to the surface. Rainfall replenishes it directly, but this also makes it easily reached by contaminants.

A confined artesian aquifer, like ours, is sealed above and below by impermeable rock or clay. That seal is what creates the pressure and also protects it from surface-level contamination. The water inside is isolated from environmental impact, sometimes for hundreds of years.

This is also what gives artesian water a consistent mineral profile. The water has been in contact with the same rock formations for years, absorbing the same minerals, undisturbed by seasonal changes on the surface.

What Makes Artesian Water Different from Spring Water or Purified Water?

This is where a lot of labels can get confusing. "Spring," "artesian," and "purified" all sound premium, but actually describe very different things geologically.

Here's the actual breakdown:

 

While spring water also comes from an underground source, it is not necessarily under pressure or, more importantly, confined. The FDA defines spring water as water that flows naturally to the surface or is collected via a borehole, but the source doesn't have to be a pressurized, sealed aquifer. That matters because an unconfined source is more exposed to what's happening at the surface.

Purified water starts from whatever source is available, often municipal tap water, and goes through reverse osmosis or distillation processing to remove essentially everything. The result is very clean, but also very flat, as its stripped of any naturally occurring minerals that give water its taste and character.

Artesian water sits in its own category: naturally protected by geology, naturally pressurized, and naturally mineral-rich from its time underground. The minerals aren't added back in after processing. They were never removed in the first place.

Is Artesian Water Naturally Alkaline?

Sometimes, yes, but it depends on the geology of the specific aquifer.

As water moves through rock formations underground, it picks up minerals like calcium, magnesium, and bicarbonate. These minerals can raise the water's pH above the neutral 7.0 mark, making it naturally alkaline.

That being said, some aquifers produce water with a neutral or even slightly acidic pH, depending on what's in the surrounding geology. So to know if an artesian water is alkaline, you’d have to look at the specific source.

Tahoe Artesian Water, for example, has a natural pH of 8.2. That alkalinity comes from the minerals the water absorbs as it moves through the granite and volcanic rock formations in the Tahoe National Forest. If you're looking for naturally alkaline artesian water with a clean, light mineral profile, the source matters more than the label.

What Does TDS Mean on a Water Label?

A TDS (total dissolved solids) reading tells you how much mineral content is in the water. Tahoe Artesian water has a TDS of 98, low enough to taste clean and smooth, but high enough to carry a soft mineral character. For comparison, heavily mineralized waters can run 500+ TDS, which some people find too strong or even bitter on the palate.

Does It Matter Which Aquifer The Water is From?

A lot of premium water brands lean hard on the word "artesian" without sharing much about the aquifer or aquifers they source from.

Here's what's worth paying attention to when you're checking out an artesian source:

• Recharge Zone Elevation — A higher elevation will generally mean less agricultural and industrial runoff can reach the aquifer. Snow and rain at altitude tend to be cleaner starting points.
• Aquifer Protection — Is the land above the aquifer protected from development, farming, or contamination? Private or protected land matters.
• Nitrate Level — Nitrates are a common indicator of agricultural runoff reaching groundwater. Zero detected nitrates is a meaningful data point, not just a marketing line.
• Ownership and Stewardship — Large-scale commercial extraction can stress an aquifer over time. A family-owned source with controlled extraction is a different model than industrial-scale pumping.
• Virginity Rating — The Fine Water Society uses a virginality rating to describe how isolated a water source is from human influence. A "Superior" rating means the source has minimal exposure to the outside environment.

How does Tahoe Artesian’s Aquifer Stack Up?

Tahoe Artesian is sourced from a protected aquifer at 7,000 feet in the Tahoe National Forest. The aquifer is naturally pressurized, and only the excess flow is bottled. The source holds a Superior virginality rating from the Fine Water Society, and third-party testing confirms zero detected nitrates.

That's not a sales pitch. It's just what water looks like from a well-protected source.

If you’re in the western US, there's also value in drinking our artesian water from a local, eco-concious standpoint. Water that travels thousands of miles in a container ship has a very different environmental footprint than water sourced regionally.

Frequently Asked Questions

What makes water “artesian water”, exactly?

Artesian water is groundwater sourced from an aquifer, which is a trapped underground pocket of water sealed between impermeable layers of clay or rock. Naturally pressurized, the water is forced upward, without pumping. The term refers specifically to this geological setup, not to a particular taste, mineral content, or quality level.

Is artesian water better than regular water?

"Better" depends on what you're comparing. Artesian water that is sourced from a well-protected, high-elevation aquifer tends to have a consistent mineral profile and low exposure to surface contaminants. Compared to municipal tap water (which is treated with chlorine and fluoride) or purified water (which is stripped of minerals through reverse osmosis), naturally sourced artesian water offers a different character, making it not necessarily superior in every context, but meaningfully different in origin and composition.

How is artesian well water different from a regular well?

A regular well draws from an unconfined aquifer, where the water table is open to the surface. A pump is usually required to bring water up. An artesian well taps a confined aquifer under pressure, so the water rises on its own, sometimes all the way to the surface without any mechanical help. The confined nature of the aquifer also provides more natural protection from surface contamination.

Does artesian water have minerals in it?

Generally, yes. As water moves slowly through rock and sediment underground, it picks up naturally occurring minerals like calcium, magnesium, silica, bicarbonate, and others depending on the local geology. This is what gives artesian water its distinctive taste and, in many cases, a naturally elevated pH. The specific mineral content varies by source, which is why TDS and pH readings differ across artesian water brands.

Is artesian water the same as alkaline water?

Not always. Artesian water can be naturally alkaline if the aquifer geology raises its pH above 7.0, but this isn't guaranteed. Many artesian sources produce water with a neutral pH. Separately, a lot of "alkaline water" on the market has had minerals or electrolytes added to raise the pH artificially. Naturally alkaline artesian water, where the pH comes from the source itself, is a different product than artificially alkalized water, regardless of how similar the labels look.

 

Ready to taste the difference? Try our water and see what a protected high-altitude source actually tastes like.