Residents were told not to drink the water, bathe in it or cook with the water and only use it for flushing and fire emergencies. Boiling it will not remove the chemicals.
"Right now, our priorities are our hospitals, nursing homes, and schools," Tomblin said in a statement. "I've been working with our National Guard and Office of Emergency Services in an effort to provide water and supplies through the county emergency services offices as quickly as possible."
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NBC affiliate WSAZ said the chemical leaked from a tank at Freedom Industries in Charleston. The leaked product is 4-methylcyclohexane methanol, which is used in the froth flotation process of coal washing and preparation, according to WSAZ.
Schools will be closed Friday in some of the affected counties.
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West Virginia American Water did not provide a timeline for the clean-up process, said Jennifer Sayre, a spokeswoman for the Kanawha County Manager.
Sayre urged residents not to panic and rush out to grocery stores to purchase bottled water, as local officials were working with the Federal Emergency Management Agency to open water distribution centers.