Is Kirkland Signature Water Safe?

If you're a regular shopper at Costco, then you're no doubt used to seeing people pushing around carts with a pallet or two of Kirkland bottled water. According to Beverage Industry, bottled water is the most popular drink in the United States, and with Costco's cheap prices, it's no surprise that Kirkland bottled water is a hot seller. 

Not all bottled water is created equal though, and brands source their water from different places — and have different filtration processes as well. This all makes finding the best water a little tricky for consumers. So is Kirkland Signature bottled water worth the price, and more importantly, is it safe to drink?

What's up with those other ingredients in Kirkland water?

The only ingredient in a bottle of bottled water should really just be water, right? One Twitter user in 2014 questioned Costco on their bottled water when he posted a photo of their water with ingredients such as "bicarbonate" and "magnesium oxide." At first glance, this might seem a little bit concerning, but these are actually natural minerals added back into the water during the filtration process (via Consumer Reports).

Just like as with their Kirkland beer, Costco isn't in the water business, and they get their water from the California-based Niagra Bottling company.  A detailed report of Kirkland's, excuse us, Niagra's bottled water highlights that once the spring water or well water is sourced, it's processed through carbon filtration, aeration, and/or UV filtration. It then goes through a filter to remove "microbiological contaminants." From there, it's purified through a re-mineralization process that adds in those minerals with the fancy, hard-to-pronounce names. 

This is all done in accordance with the guidelines set forth by the FDA that are on par with (and in some aspects, more stringent than) the EPA's regulations under the Safe Drinking Water Act. Long story short, yes, Kirkland's Signature water is totally safe to drink, and a medical doctor-approved review on Is It Bad For You? gave the water an A grade. So drink up.