Who Has the Cleanest Bottled Water? A Guide to Purity

November 12, 2025 •

4 min read

A 2021 study revealed major variations in bottled water quality, highlighting the importance of brand transparency and independent testing. To determine who has the cleanest bottled water, consumers must look beyond marketing and understand key factors that influence water's content and potential contaminants.

Quick Summary

This article evaluates which bottled water brands are the cleanest by exploring different types of water, purification methods like reverse osmosis, and analyzing key metrics like Total Dissolved Solids (TDS).

Key Points

Purity isn't simple: 'Cleanest' can mean the lowest TDS (purified water) or naturally-occurring minerals (spring/mineral water).
Low TDS is a key indicator: Reverse osmosis and distillation create water with very low TDS, like Aquafina, but remove beneficial minerals.
Natural sources retain minerals: Spring water brands like Mountain Valley or Icelandic Glacial are naturally pure and retain a unique mineral profile.
Packaging affects purity: Plastic bottles can leach microplastics, so options in glass or aluminum, like Mountain Valley and Liquid Death, offer a cleaner choice.
The 'cleanest' isn't always 'healthiest': Extremely low-TDS water lacks beneficial minerals found in natural spring and mineral waters.
Research your choice: Look for brands that are transparent about their source, purification methods, and test results.

The Quest for Purity: Defining 'Clean'

When we talk about the 'cleanest' bottled water, the term can be misleading. For some, it means water with the lowest Total Dissolved Solids (TDS)—a measure of inorganic minerals, salts, metals, and other particles dissolved in the water. Water with a low TDS score has been stripped of virtually everything. For others, 'clean' refers to water that is naturally sourced and minimally processed, retaining its natural mineral profile. The truth is, the cleanest bottled water for you depends on your personal preference and health needs.

The Role of Total Dissolved Solids (TDS)

TDS is often used as a benchmark for bottled water purity. It is measured in parts per million (ppm). Distilled water will have a TDS of 0, as the boiling process removes all minerals and impurities. In contrast, mineral-rich spring waters will have a higher TDS. While low TDS indicates a high degree of purification, it doesn't necessarily make the water healthier, as it also removes beneficial minerals.

Different Bottled Water Types and Their Purification Methods

Understanding how different bottled waters are processed is crucial for determining purity. Not all water is created equal.

Purified Water: This is often municipal tap water that has been treated extensively. Key purification methods include:
- Reverse Osmosis: Water is forced through a semipermeable membrane to remove contaminants. Brands like Aquafina and Dasani often use this method.
- Distillation: Water is boiled into steam, which is then condensed back into liquid, leaving impurities behind. This results in extremely pure water, but it often tastes 'flat'.
Spring Water: Sourced from an underground formation from which water flows naturally to the surface. It undergoes minimal processing, usually just filtration and UV light disinfection, and retains its naturally occurring minerals.
Mineral Water: Similar to spring water, but it comes from a mineral spring and contains a high concentration of specific minerals like calcium, magnesium, and sulfur.
Alkaline Water: Some brands ionize their water to raise its pH level, while others are naturally alkaline due to their source. Essentia is a popular ionized option, while Icelandic Glacial is naturally alkaline.

Comparing Top Bottled Water Brands for Cleanliness

To see who has the cleanest bottled water, let's compare some popular brands based on source and processing.


Brand	Source	TDS (approximate ppm)	Purification Method	Notes
Aquafina	Municipal	1-4	Reverse Osmosis	Very low mineral content, bland taste.
Essentia	Municipal	23	Microfiltration, Reverse Osmosis, Ionization	Electrolytes added for taste, high pH.
Fiji	Artesian Aquifer	131	Filtration, UV light	Retains volcanic rock minerals, higher TDS.
Icelandic Glacial	Spring	52	Filtration	Naturally alkaline from lava rock filtration.
Mountain Valley	Spring	Varies	Filtration	Bottled at source since 1871, mineral-rich.
Dasani	Municipal	28	Reverse Osmosis, Mineral additives	Minerals added back in for taste.

Interpreting the Results

Based on low TDS, Aquafina is among the purest, as it's processed to remove nearly everything. However, its low mineral content can be a drawback for those seeking more than just hydration. Brands like Icelandic Glacial and Mountain Valley, while having higher TDS, are prized for their natural purity and mineral content derived from pristine, natural sources. Essentia achieves a high pH and low TDS through advanced processing, making it a favorite for those who prefer ionized water.

The Problem with Plastic

Beyond the water itself, the packaging is a major factor in determining true 'cleanliness'. Many tests show that plastic bottles can contain microplastics which may leach into the water, especially when exposed to heat. This has led many consumers to seek out alternatives like glass or aluminum bottles. Brands like Mountain Valley and Liquid Death offer these options, eliminating the risk of microplastic contamination from the bottle itself.

Making an Informed Decision

To find the cleanest bottled water for your needs, consider the following steps:

Define your priority: Do you want the absolute lowest TDS (purified water) or naturally-occurring minerals (spring/mineral water)?
Check the source: Reputable brands are transparent about their water source and purification process.
Read the report: Some companies, like Liquid Death, provide detailed bottled water quality reports.
Evaluate the packaging: Consider glass or aluminum options to avoid potential microplastic exposure.
Consider home filtering: For maximum purity and convenience, a high-quality home filtration system offers a consistent and environmentally friendly alternative.

Conclusion: Your Cleanest Choice

Ultimately, there is no single best answer to who has the cleanest bottled water. For the absolute lowest mineral and impurity content, purified water brands like Aquafina are a top choice. However, for those seeking natural minerals and a rich taste, spring and mineral waters like Mountain Valley Spring or Icelandic Glacial are superior choices. The final decision rests on your definition of cleanliness—whether it's defined by minimal processing, minimal content, or sustainable packaging.

Consider investigating independent water quality tests and reports, like those by the Oasis app, to gather additional data to make an informed decision for your health and hydration needs.

Frequently Asked Questions

TDS is a measure of all the inorganic and organic substances dissolved in water. It is measured in parts per million (ppm). For bottled water, a low TDS indicates a high level of purification, while a higher TDS can indicate a higher mineral content, often found in natural spring water.

Not necessarily. Purified water, such as Aquafina, is stripped of most minerals and contaminants through processes like reverse osmosis. Spring water is naturally filtered and retains minerals. One is not inherently 'cleaner' or 'better' than the other; it depends on whether you prefer mineral-free or mineral-rich water.

Yes, research shows that many brands of bottled water in plastic containers can contain microplastics. This is a significant concern for some consumers. To avoid this, consider bottled water packaged in glass or aluminum, or use a reusable bottle with a home filter.

Alkaline water has a higher pH level than regular drinking water. Proponents claim it can neutralize acid in the body and provide better hydration, but scientific evidence is mixed. Brands like Essentia and Icelandic Glacial are popular alkaline choices.

Both spring and mineral water come from underground sources. Mineral water, by definition, must contain specific amounts of naturally-occurring minerals and salts, giving it a more distinct flavor. Spring water may have minerals but is not defined by their concentration.

Yes, they undergo rigorous purification processes like reverse osmosis to remove contaminants, so they are considered clean. The main difference is they start with municipal water and add minerals back in (Dasani) or keep them stripped (Aquafina), rather than sourcing from natural springs.

While you can't test for all contaminants at home, you can use a TDS meter to measure the level of dissolved solids. Low TDS (under 50 ppm) generally indicates high purity. However, a higher TDS in mineral water is expected due to naturally dissolved minerals.