That bottled water you’re drinking could have come from a faucet the next town over or from a company with a history of bacterial contamination.

But you wouldn’t know that from the label, according to an environmental group that examined 173 different brands of bottled water on the market.

On Wednesday, the Environmental Working Group, a Washington, D.C., advocacy outfit, released its “Bottled Water Scorecard,” a rundown of the data displayed – or not – on the containers of one of the nation’s most popular retail beverages.

The group found that only three water bottles had three key pieces of data – the water’s source, how it’s purified and the results of any tests for contaminants. The brands were: Gerber Pure Purified Water, Nestle Pure Life Purified Water and Penta Ultra Purified Water.

The 170 others lacked at least one of the three pieces of information; but many had none. In contrast, municipal water purveyors must provide data on where their supplies originate, treatment methods and any violations of drinking water standards under federal law.

“A lot of people drink bottled water because they don’t trust their tap water,” said Jane Houlihan, senior vice president for research at the Environmental Working Group. “But municipal utilities are required to be transparent. With bottled water you’re completely in the dark.”