State investigators discovered the material was leaking from the bottom of a storage tank, and had overwhelmed a concrete dike meant to serve as "secondary containment" around the tank, Dorsey said.
"That was going over the hill into the river," Dorsey said. "Apparently, it had been leaking for some time. We just don't know how long."
The state Department of Homeland Security has contacted the Federal Emergency Management Agency to try to have more bottled water brought into the area, Tomblin said. Later Thursday, the governor said he'd spoken with FEMA's director, Craig Fugate.
Freedom Industries produces "freeze conditioning agents, dust control palliatives, flotation reagents [and] water treatment polymers," among other chemicals, according to its website.
Freedom Industries officials, including the company's president, Dennis Farrell, did not return repeated phone calls Thursday.
Earlier in the day, some emergency officials were saying they had found little information about potential toxic effects of the substance.
One material-safety data sheet, or MSDS, said, "no specific information is available ... regarding the toxic effects of this material for humans.
"However, exposure to any chemical should be kept to a minimum," the MSDS said. "Skin and eye contact may result in irritation. May be harmful if inhaled or ingested."
Less than three hours before the state of emergency was declared, an official statement from West Virginia American Water was issued assuring the public and news media that the spill "does not present a health risk to customers."
The water company announced an emergency news conference regarding the spill at 5:09 p.m. and Tomblin officially announced the state of emergency around 6 p.m.
"This is not a chemical that we deal with every day. It's not the type of thing we would see in dealing with a water treatment plant," McIntyre said. "We took some time to understand even what we were dealing with at the time."
McIntyre said the company will have to do "extensive flushing" to make sure the contaminant is out of its system. He couldn't say how long the process will take.
State Homeland Security Director Jimmy Gianato advised those customers with concerns of exposure or consumption of the chemical can call the Poison Control Center at 1-800-222-1222. If someone is obviously sick, they should go to the hospital or call 911, Gianato said.
House of Delegates spokeswoman Stacey Ruckle said the House wouldn't conduct any business today, and would reconvene at 1 p.m. Monday.
Staff members at Thomas Memorial and Saint Francis hospitals were told not to use water except for flushing the toilets, spokeswoman Paige Johnson said Thursday.
The hospitals have some bottled water on hand and they're getting more, Johnson said.
She didn't know of any patients coming to the hospital complaining of problems associated with drinking the contaminated water.
CAMC has canceled all procedures for today, officials said.
Meadowbrook Acres Nursing Center, a 60-bed nursing home in Charleston, was prepared, said administrator Kim Toney.
"We keep a three-day emergency supply, so we should be fine," Toney said. "We're planning for more but we've got enough to last until we can get more water in here."
At the Charleston Town Center Mall, marketing director Lisa McCracken said Thursday evening, "We've closed our restaurants and we closed our treateries. We've turned off all the public restroom faucets, and we have issued an advisory mall-wide to the tenants, telling them not to use the faucets in their establishments."
Crystal Del Giudice, a supervisor at the Starbucks coffee shop in the mall, said employees ran out to buy hand sanitizer so they could clean themselves up after they closed the store.
"It's like the apocalypse," she said, half-jokingly.
Several mall restaurants had signs posted, informing customers that they were closed because of the water emergency.
At the Kroger in Kanawha City, shelves in the bottled-water aisle were nearly bare. A Charleston police officer kept an eye on the crowd.
Kerstin Halstead of Campbells Creek was doing her regular shopping when her husband called and told her to buy water.
"People have been grabbing it like crazy," she said as she loaded two cases of bottled water into her SUV, "and some people were getting -- well, they could have shared more."
The East End Rite-Aid ran out of water just after 6:30 p.m., according to a store employee. Customers were buying ice instead.
Ruby Piscopo, 28, of Charleston, and Christi Pritt, 29, of Belle, were having an after-work drink when they heard about the chemical leak. "We started getting texts and changed the TV to the news," Piscopo said. "I wasn't concerned until someone said it could go on for days."
The two bought $30 worth of water between them. They had other friends buying water throughout the city, with the intention of splitting it up later.Staff writers Ken Ward Jr., Caitlin Cook, Rusty Marks, Lori Kersey and David Gutman contributed to this report.
Reach Rachel Molenda at rachel.mole...@wvgazette.com or 304-348-5102.