UPDATE 2-US lawmakers seek info from bottled water companies

* Pepsi, Coke, 11 others asked for information

* Companies asked to document water source

* FDA lacks authority to regulate safety (Adds GAO report on bottled water, Stupak remarks in paragraphs 8-10)

WASHINGTON, July 8 (Reuters) - U.S. lawmakers requested information on Wednesday from 13 bottled water sellers including PepsiCo (PEP.N) and Coca-Cola Co (KO.N) about the source of their water and its testing.

A congressional hearing earlier Wednesday "found that neither the public nor federal regulators know nearly enough about" where bottled water comes from or what measures are taken to make sure it is safe, Democratic Representative Bart Stupak said in a statement.

"The majority of consumers purchase bottled water because of perceived health and safety benefits, but they actually know very little about the quality of the water they are buying," Stupak added.

In letters to the companies, the lawmakers asked for documents related to testing of bottled water and its sources, plus names and locations of each company's water sources.

Companies that received the letters included PepsiCo, Coca-Cola, Dr Pepper Snapple Group Inc (DPS.N) and Nestle (NESN.VX). Representatives for the companies could not immediately be reached on Wednesday.

The letters were sent by Stupak and House Energy and Commerce Committee Chairman Henry Waxman, a Democrat who has aggressively pursued information from companies on consumer issues. Stupak chairs the committee's investigations panel.

Bottled water makers make millions off people who believe their products are purer than tap water, but consumers do not realize that they are less regulated than plain old tap water, according to a Congressional report released on Wednesday.

At the hearing, lawmakers also heard from the General Accountability Office, which said the U.S. Food and Drug Administration has little power to regulate the safety of bottled water.

"Of particular note, FDA does not have the specific statutory authority to require bottlers to use certified laboratories for water quality tests or to report test results, even if violations of the standards are found," a new GAO report said.

Stupak said that bottled water has been recalled in recent years due to contamination by arsenic, bromate, cleaning compounds, mold, and bacteria. (Reporting by Lisa Richwine; Editing by Steve Orlofsky)