What bottled water is filtered water and how is it made?

December 26, 2025 •

4 min read

According to the NRDC, a 1999 report found that as much as 25% of bottled water is simply filtered tap water, a practice that continues today with major brands. This article explains what bottled water is filtered water and the various methods used for purification.

Quick Summary

Purified bottled water is often filtered municipal tap water, unlike spring water which comes from natural sources. Different filtration techniques are used to produce it.

Key Points

Purified Water is Filtered Water: Brands labeled 'purified water', such as Aquafina and Dasani, use advanced filtration techniques on public water sources.
Intensive Treatment: The purification process for bottled water often includes reverse osmosis, activated carbon filtration, and UV sterilization to remove contaminants and ensure consistent taste.
Spring Water is Different: Spring water is collected from natural underground sources and undergoes minimal processing, retaining its natural mineral content.
Filtering vs. Purifying: While all purified water is filtered, basic filtered water may not have undergone the same level of rigorous treatment, such as reverse osmosis, that purified water does.
Taste and Minerals: Purified water offers a consistent, neutral taste, whereas spring water's taste is influenced by its mineral composition.
Safety Regulations: Both purified and spring bottled waters are regulated by the FDA to ensure safety, although their processing and sourcing methods differ significantly.

Understanding Bottled Water Categories

Not all bottled water is created equal. The source and treatment process are the primary factors that differentiate the types found on store shelves. The most common varieties include purified water, spring water, mineral water, and distilled water. The key to understanding filtered bottled water is to look for the terms 'purified' or 'drinking water' on the label, which indicates it has undergone a specific treatment process.

Purified Water vs. Spring Water

The most direct answer to the question "what bottled water is filtered water?" lies in the 'purified water' category. Brands like Aquafina and Dasani explicitly state their water is purified, often sourced from public water systems. These companies invest in multi-step purification systems to ensure a consistent and clean taste, regardless of the municipal source. In contrast, spring water is collected directly from a natural underground source and is minimally processed, typically undergoing only filtration to remove particles and ozone treatment for disinfection. It retains its natural mineral content, which gives it a distinct taste.

The Advanced Filtration Processes Behind Purified Water

Purified bottled water isn't just a basic filtering of tap water; it involves a rigorous, multi-stage process to remove impurities and contaminants. This intensive treatment is what allows brands to market their water as pure and consistent in taste. The specific techniques vary by brand but often include a combination of the following steps:

Reverse Osmosis (RO): This is one of the most common and effective methods. Water is forced under high pressure through a semi-permeable membrane. This membrane has extremely small pores that block most dissolved solids, inorganic chemicals, and microbes, resulting in very pure water.
Activated Carbon Filtration: Water is passed through beds of activated carbon, which uses adsorption to trap organic compounds, chlorine, pesticides, and other chemicals that can affect the water's taste and odor.
Ion Exchange: This process is used to soften water and remove dissolved mineral salts by exchanging charged ions.
Micron Filtration: This involves passing the water through a series of increasingly smaller filters to remove larger sediment, dirt, and microscopic particles.
Ultraviolet (UV) Sterilization and Ozonation: These are methods of disinfection. UV light and ozone gas are used to kill bacteria, viruses, and other microorganisms to ensure the water is safe without adding chemicals.

Popular Brands Using Filtered Water

It is important for consumers to understand the source and treatment of their bottled water. Several major brands utilize municipal or public water sources that are then heavily filtered and purified. This is a standard and safe practice, though it does mean the water is not naturally sourced from a spring or well.

Here are some of the most well-known brands that use filtered municipal water:

Aquafina: Uses a multi-stage process called Hydro-7, which includes reverse osmosis, ozonation, and carbon filtration to purify its public water sources.
Dasani: Sourced from municipal supplies and purified through reverse osmosis and a proprietary blend of minerals for taste.
Nestlé Pure Life: This brand also uses municipal sources and then purifies the water before bottling.
LIFEWTR: Like other purified brands, LIFEWTR starts with municipal sources and purifies the water, adding electrolytes for taste.

Filtered Water vs. Spring Water: A Comparison


Feature	Filtered (Purified) Water	Spring Water
Source	Municipal tap water or other public systems	Natural underground spring or borehole
Filtration	Intensive, controlled processes like reverse osmosis, carbon filtration, and UV sterilization	Natural filtration through rock and earth, followed by minimal processing like micron filtration and ozonation
Mineral Content	Stripped of most natural minerals; some electrolytes may be added back for taste	Retains natural minerals from its source, such as calcium and magnesium
Taste	Consistent, neutral, and clean taste due to removal of impurities and minerals	Distinct taste that can vary slightly depending on the mineral composition of the source
Regulations	Heavily regulated by the FDA and often meets more stringent IBWA standards	Also regulated by the FDA and must originate from a true spring source

Conclusion: Which to Choose?

Ultimately, the choice between purified, filtered water and naturally-sourced spring water comes down to personal preference. Both are safe for consumption, as both are required to meet or exceed FDA safety standards. Purified water offers a consistent, neutral taste and guaranteed purity through intensive human-driven filtration processes. Spring water, on the other hand, provides a unique taste profile and the benefit of natural minerals. Consumers seeking absolute purity and consistency often prefer purified water, while those who favor a natural mineral content and taste may opt for spring water. Understanding the difference empowers you to make an informed choice based on your priorities for taste, mineral content, and production process. For more information on the safety of bottled water, you can consult reports from reliable organizations such as the Natural Resources Defense Council (NRDC).

Frequently Asked Questions

Purified water has undergone more intensive treatment than basic filtered water. While all purified water is filtered, it also typically goes through additional processes like reverse osmosis, distillation, or deionization to remove virtually all chemicals and dissolved solids, resulting in a higher level of purity.

Yes, Aquafina sources its water from public water systems and then purifies it using a rigorous multi-stage process that includes reverse osmosis, ozonation, and carbon filtration. The company refers to this as their Hydro-7 purification system.

Yes, Dasani, owned by Coca-Cola, uses municipal tap water as its source. It then purifies the water through reverse osmosis and adds a proprietary blend of minerals for a consistent taste.

Yes, water from public systems is already regulated and safe to drink. The additional filtration and purification processes used by bottled water brands remove more impurities, making it exceptionally clean and safe for consumption.

Spring water undergoes a natural filtration process as it travels through underground rock and soil. Bottling companies then perform minimal additional processing, such as micron filtration and ozonation, to ensure safety and remove particles.

Both are safe to drink, and the better option is based on personal preference. Purified water offers maximum consistency and purity, while spring water provides natural minerals that some people prefer for taste and health benefits.

Reverse osmosis is a process that purifies water by forcing it under pressure through a semi-permeable membrane. This removes dissolved salts, minerals, and other contaminants, resulting in a very high level of water purity.