Spring water is often mistaken for being equal or interchangeable with purified water. However, spring water often contains many of the same impurities found in well or tap water. In fact, since springs feed our rivers, there is a lot of spring water in our tap water! Spring water generally has the same TDS range as tap water.
Many spring water companies advertise their water as “100% pure—” but if it’s not purified, what does that mean? The “pure” part actually refers to the source, not the water itself—in that 100% of that bottle’s contents came from an underground source (rather than surface water). This clever wording leads many people to believe that spring water is just as clean as purified water.
Thanks to this crafty marketing, spring water often conjures up natural, pleasant imagery. In reality, most spring water is not actually bottled at the source, but rather, is pumped into large tanker trucks from the source to be transported to the bottling facility. The water in those trucks must be chlorinated or ozonated at all times to protect against contamination. In this sense, spring water is hardly different from tap water, since it is largely treated the same way. Once the water is at the bottling facility, it goes through a carbon filtration process to remove the chlorine. This process may separate spring from tap water, but nitrates, metals, and more are likely to remain.
Distilled water is processed by boiling H2O out of its contaminants. Many of said contaminants include inorganic minerals or metals. Those impurities have a much higher boiling point than water’s boiling point of 212 degrees Fahrenheit. So, the steam that results from the boiling is captured and cooled—and the water that results from the steam is what is classified as distilled water. Because many of the volatile compounds in water have a lower boiling point than water, they boil off first. As a result, it is important to employ additional purification methods beyond distillation in order to have truly clean, pure water.
Filtered water is what you are most likely to find in a grocery store. It is typically sourced from municipal tap water, which is then run through carbon filters to remove the chlorine (which improves the taste) and sometimes a micron filter as well. After the filtering, it is ozonated and bottled. In essence, filtered water is quite similar to spring water. It comes from a “natural” source, goes through minimal filtration, and is then bottled and shipped to market.
The source of purified water isn’t what makes it the best choice on the market—it’s the purification methods that separate purified water from the rest of the pack. Purified water goes through a process similar to what filtered water goes through, but with a few added steps like reverse osmosis, distillation, or deionization. The end result is far purer than filtered, spring, or tap water.