Although the allegations came from Halliburton's own water quality experts, the company once headed by Vice President Dick Cheney denied there was a contamination problem at Camp Junction City, in Ramadi.
"We exposed a base camp population (military and civilian) to a water source that was not treated," said a July 15, 2005, memo by William Granger, the official for Halliburton's KBR subsidiary who was in charge of water quality in Iraq and Kuwait.
"The level of contamination was roughly 2x the normal contamination of untreated water from the Euphrates River," Granger wrote in one of several documents.
The Associated Press obtained the documents from Senate Democrats who are holding a public inquiry into the allegations Monday.
Sen. Byron Dorgan, D-N.D., who will chair the session, held a number of similar inquiries last year on contracting abuses in Iraq. He said Democrats were acting on their own because they had not been able to persuade committee chairmen in the Republican-run Senate to investigate.
The company's former water treatment expert at Camp Junction City said he discovered the problem last March, a statement confirmed by his e-mail the day after he tested the water.
While bottled water was available for drinking, the contaminated water was used for virtually everything else, including handwashing, laundry, bathing and making coffee, said water expert Ben Carter of Cedar City, Utah.
Another former Halliburton employee who worked at the base, Ken May of Louisville, Ky., said there were numerous instances of diarrhea and stomach cramps, problems he also suffered.
A spokeswoman for Halliburton, Melissa Norcross, said its own inspection found neither contaminated water nor medical evidence to substantiate reports of illnesses at the base. The company now operates its own water treatment plant there, she said.
A military medical unit that visited Camp Ramadi in mid-April found nothing out of the ordinary in terms of water quality, said Marine Corps Maj. Tim Keefe, a military spokesman. Water-quality testing records from May 23 show the water within normal parameters, he said.