What Bottled Water Is Just Water? The Definitive Guide

October 1, 2025 •

4 min read

According to FDA regulations, for a bottled water to be labeled 'purified,' it must contain no more than 10 parts per million of Total Dissolved Solids (TDS). This rigorous filtration often starts with municipal tap water, revealing that some purified bottled water is just water from a different source, stripped of its minerals.

Quick Summary

This guide breaks down the critical differences between purified and spring bottled water. It explains which popular brands use municipal water as their source and clarifies why the labeling can be so misleading for consumers.

Key Points

Purified water is extensively filtered and often starts as tap water, with brands like Dasani and Aquafina using this process.
Spring water is sourced from an underground aquifer and retains its natural mineral content, which gives it a unique taste.
The FDA regulates both bottled and tap water, with standards for bottled water being compatible with EPA standards for tap water.
Marketing plays a significant role, often creating an emotional connection to a brand by highlighting a 'pristine' origin, even for purified tap water.
Key purification methods include reverse osmosis (RO) and distillation, which remove dissolved ions and contaminants to make water purer.
Low TDS is a key indicator of purified water; to be labeled 'purified,' it must have less than 10 parts per million of total dissolved solids.

The Misconception of 'Pure' Bottled Water

Many consumers purchase bottled water assuming it comes from a pristine, natural source. However, the bottled water market is diverse, and the term 'bottled water' can refer to a variety of products with very different origins and treatments. While some water is sourced from natural springs, others, often labeled simply as 'purified water,' are sourced from municipal supplies—the same water that flows from your tap. This purified water undergoes extensive treatment to remove impurities and minerals, making its marketing a powerful tool for creating a premium product from a common source. Understanding these differences empowers you to make an informed choice based on your preferences for taste, mineral content, and environmental impact.

The Defining Differences: Purified vs. Spring

Purified Water: The Filtered Truth

Purified water can originate from almost any source, including municipal tap water or groundwater. To earn the 'purified' label, it must undergo a rigorous purification process that removes chemicals, contaminants, and dissolved solids. Common purification methods include:

Distillation: The water is boiled into steam, and the steam is collected and condensed back into liquid, leaving impurities behind. This method removes nearly 99.9% of minerals.
Reverse Osmosis (RO): Water is forced through a semipermeable membrane to remove dissolved ions, salts, and larger molecules.
Deionization: Mineral ions are removed through a chemical ion-exchange process.

After these processes, minerals are sometimes added back to enhance the taste. Major brands known for using purified water include Aquafina, Dasani, and Nestlé Pure Life. For example, PepsiCo confirmed Aquafina is sourced from municipal water and purified using reverse osmosis. Similarly, Dasani, owned by Coca-Cola, is filtered tap water with added minerals.

Spring Water: The Naturally Sourced Option

Spring water must be sourced directly from an underground formation from which water flows naturally to the surface. This means the water's taste and mineral composition are naturally derived from the geological formations it passes through, giving each source a unique profile. Unlike purified water, spring water undergoes minimal processing, primarily to remove bacteria and certain contaminants, while keeping its natural mineral content intact. Brands like Evian, Fiji Water, and Mountain Valley Spring Water market themselves based on their specific, often remote, natural source.

Comparison: Purified Water vs. Spring Water


Feature	Purified Water	Spring Water
Source	Any water source, including municipal tap water	An underground aquifer that flows naturally to the surface
Treatment	Extensive filtration (RO, distillation, deionization) to remove nearly all impurities and minerals	Minimal filtration to remove harmful contaminants while preserving natural minerals
Mineral Content	Very low (under 10 ppm TDS); minerals often added back for taste	Varies based on the natural source; minerals are naturally occurring
Taste Profile	Typically very neutral, clean, and consistent due to added minerals	Distinct taste that varies by source, influenced by natural minerals
Example Brands	Aquafina, Dasani, Nestlé Pure Life	Evian, Fiji Water, Mountain Valley Spring Water

The Purification Process Explained

The journey of purified water from a municipal source to a bottle involves several sophisticated steps. The core of this process is often reverse osmosis, a technology that uses pressure to push water through a semipermeable membrane.

Pre-Filtration: Before reaching the RO membrane, water is filtered to remove larger particles and chlorine. An activated carbon filter is typically used for this stage.
Reverse Osmosis (RO): The pre-treated water is forced through a fine membrane, which blocks dissolved salts, minerals, and other contaminants. This process is highly effective at purifying water but can be wasteful, producing a stream of concentrated wastewater.
Post-Treatment: After RO, the water is ultra-pure, with a flat taste. Some bottlers add a proprietary blend of minerals, like magnesium sulfate or potassium chloride, to create a consistent, desirable flavor profile.
Disinfection: To ensure microbiological safety, the water is often treated with ozone or ultraviolet (UV) light before bottling.

DuPont offers detailed information on reverse osmosis technology, including its use in creating high-purity water for various applications.

Your Water Choice: Purity, Minerals, or Price?

Choosing your bottled water comes down to a balance of factors. If your priority is the removal of as many dissolved solids as possible, with a consistent, clean taste, then purified water is your ideal choice. However, if you prefer water with naturally occurring minerals that vary by source and flavor, spring water is the way to go. For cost-conscious and environmentally-minded individuals, filtering your own tap water with a home reverse osmosis system offers a sustainable and economical alternative to constantly buying bottled products.

Conclusion

Not all bottled water is created equal. While spring water is naturally sourced and filtered, purified water often begins as tap water before being stripped of its minerals and contaminants through industrial processes like reverse osmosis. The next time you are in the bottled water aisle, remember that terms like 'pure' and 'natural' are marketing tools. Reading the label to check the source and treatment method is the most reliable way to know if you are buying filtered tap water or a genuinely natural spring product.

Frequently Asked Questions

Yes, Dasani is purified water, which starts as municipal tap water. It undergoes a process of filtration and then minerals are added back for taste.

The main difference is the source. Spring water comes from a natural underground source and has naturally occurring minerals. Purified water can come from any source, including tap, and has had most minerals and impurities removed.

Yes, purified water is safe to drink. The extensive filtration process removes harmful contaminants. For most healthy people, the removal of minerals is not a concern, as most of our mineral intake comes from food.

Yes, they taste different. Purified water has a very neutral, consistent taste. Spring water's taste varies by its natural source and the minerals present.

Reverse osmosis (RO) is a purification method that forces water through a semipermeable membrane to remove dissolved solids, salts, and impurities. RO water is often used for drinking and industrial applications.

Distilled water is a type of purified water created by boiling and condensing steam, a process that removes almost all minerals and impurities. It is used in medical and industrial applications, and is safe to drink.

Bottled water is regulated by the FDA as a packaged food, while tap water is regulated by the EPA. FDA regulations for bottled water are designed to be as stringent and protective of public health as EPA standards for tap water.