Officials had "no timeline" for when a ban on water would be lifted after the chemical MCHM was found to have contaminated the Kanawha Valley water system in West Virginia, affecting up to 300,000 people.
"We don't know that the water's not safe, but I can't say it is safe," West Virginia American Water President Jeff McIntyre said in a news conference today. "Until we get out and flush the actual system and do more testing, we can't say how long this [advisory] will last at this time."
The chemical leak was reported Thursday morning, outside a storage facility less than a mile from American Water's treatment plant in Charleston, the state's capital.
A hole was found in a 48,000-gallon tank owned by Freedom Industries and containing material used to clean coal in the coal processing plants.
McIntyre said the amount someone would have to consume would have to be "considerable" to cause harm.
Earlier, Gov. Earl Ray Tomlin issued a statement after declaring a state of emergency in nine affected counties, saying the West Virginia Department of Environmental Protection had ordered Freedom Industries to halt further leakage of the chemical into the river.
American Water issued an advisory Thursday for the counties telling customers not to drink the water under any circumstances and to only use the water to flush their toilets and as a fire suppressant.
American Water estimated that 300,000 people -- 15 percent of the state, according to the Census Bureau -- had been affected.
Karlee Bolen, 16, of Charleston, said she and her family would likely go to a relative's home, where the water had not been affected.
"I kind of want to shower and brush my teeth," she told The Associated Press.
McIntyre said they don't know how much of the chemical had reached the Elk River through the soil, but that the West Virginia Department of Environmental Protection was still working at the site.
In a news release Friday, according to the AP, Freedom Industries said it was working to stop the leak. It was estimated that it could take several weeks to clean up the facility.
McIntyre said that American Water had not communicated with Freedom Industries and that even though the plant had reached out to the company when doing risk assessment, he didn't know what, if any, information had been received from Freedom Industries.
The chemical was not one the water company knew how to quantify, though McIntyre said officials now had a "method of analysis" that was being rolled out to mobile National Guard units for testing.
Before the advisory could be lifted, the water treatment plant must get the water to a safe standard and flush the distribution system with the clean water. The advisory could then possibly be lifted by zones.
Initially, American Water thought that the contamination was a chemical called a "flocculant," a compound typically used in water treatment, and only identified the chemical later Thursday.
It determined that the plant's water treatment capacity had been oversaturated around 4 p.m. Thursday, when a strong "black licorice odor" became apparent in the finished water.
McIntyre defended the plant's water treatment capacity, saying, "We exceed all the regulatory standards for water treatment. … We're in compliance more than most other utilities."
For events like this, the plant uses powder activated carbon, which McIntyre called the "premiere treatment process."
Asked about reports of vomiting and irritation from people who came in contact with the contaminated water, McIntyre said: "I'm not able to link anybody's illness to this event."
In the meantime, mobile water haulers have been deployed to provide customers with water, and four tractor-trailer loads of bottled water have been purchased to provide residents in affected areas with water.
A federa investigation was also underway.
FEMA now says there are 75 trucks on their way from Cumberland and Frederick in Maryland, each carrying 18,500 liters of water. The arrivals will be staggered though so all 75 will not arrive at once.
FEMA said it was anticipating the first group of 53 trucks to arrive around 7 p.m. today at Yeager Airport in West Virginia.
"This has been devastating to the public at large and to the people who live in our city," said Charleston, W.Va., Mayor Danny Jones at the news conference.
The Associated Press contributed to this article.