Is Purified Water Safe to Drink?

Having safe, clean drinking water is an important part of your overall wellbeing. And when it comes to picking the right type, you may be wondering how purified water stacks up to other forms of the fluid, like tap or distilled water.

Here's what to know about purified water, including what it is, whether it's safe and water filtration advantages and disadvantages.

Purified water is water that has been processed to filter out debris, microorganisms like bacteria and viruses and other small substances like dirt and metal particles, according to January 2015 research in ‌Nanotechnology Science and Applications‌.

In other words, purified water is usually tap water that undergoes additional filtration. Common sources of purified water are certain kinds of bottled water or tap water that's passed through a home filter.

According to the U.S. Environmental Protection Agency (EPA), water purification methods include:

• Carbon filters, which can remove chlorine, lead and mercury and are commonly found in pitcher filters.
• Reverse osmosis filters, which remove the most contaminants and are typically units that you install beneath your sink.
• Ion exchange filters, or water softeners, which remove excess hard minerals from your water.

However, it's important to note tap water in the U.S. is typically safe to drink due to thorough processing at treatment plants, so additional filtration isn't always necessary, per the Centers for Disease Control and Prevention (CDC).

Now you know what purified water is. But is purified water good for you?

Yes, so long as the filter or purified bottled water you choose is up to EPA standards (look for an ANSI/NSF certification on the label, which indicates that the product meets or exceeds drinking water requirements, per the EPA).

Purified water is safe to drink because it can remove residual contaminants — like bacteria and metal — from your tap water, according to the EPA. At the same time, most purification systems will also preserve some amount of the beneficial minerals in tap water, like calcium and magnesium.

However, exactly how many contaminants are removed and how many good substances remain depends on your filtration system, per the EPA. For instance, a basic Brita filter can remove chlorine and asbestos, but may not entirely filter out metals like lead and copper (though Brita and other popular brands typically also manufacture specialized filters that remove more metal).

But overall, drinking purified water is not bad for you — quite the opposite, as long as you properly maintain your filter (more on that later).

There are advantages and disadvantages of modern purification methods. Here are some of the perks of purifying your water.

Tap water is largely safe to drink in the U.S. due to extensive processing, per the CDC. But purifying your tap water with a reverse osmosis filter adds an extra layer of protection against potentially harmful microorganisms like bacteria and viruses, according to the EPA.

Filters may improve flavor if the taste of your tap water isn't to your liking, per the EPA. That's because home filters can remove chemicals like chlorine and substances like algae, both of which may influence the taste of your water.

Another advantage of water treatment is that it may remove trace amounts of metals like copper and lead, which can leach off of deteriorating pipes and get into your tap water supply, per the American Water Works Association.

Water treatment plants typically adjust the pH of water to prevent this from happening in the first place, but home filters can provide an additional safeguard against unwanted metals.

Although extra filtration has its advantages, there are also some disadvantages of modern water purification methods. Here are some of the shortcomings of purified water.

Purified water is good for you because it's largely free of contaminants. But one of the disadvantages of water purification systems is that they may not always be able to filter out certain chemicals like pesticides, per the University of Georgia.

Purified water is good to drink — but that often comes at a price. Buying a pitcher filter or bottled water is typically more expensive than drinking tap water. And paying to install certain purification systems can cost you hundreds of dollars, according to the EPA.

Another water filter disadvantage is that it typically needs maintenance. It's important to replace the filter in your pitcher or installed purification device, otherwise it can become clogged and won't work properly, according to the EPA.

Home water filters can remove fluoride, a mineral added to tap water at treatment plants that helps prevent tooth decay on a community level, per the CDC.