(CHARLESTON, W.Va.) — Residents in several counties in West Virginia are being warned not to drink or use their water after a chemical leaked into the Elk River Thursday. MCHM — a chemical used to clean coal in coal processing plants — began leaking from a hole in a 48,000-gallon tank, West Virginia Department of Environmental Protection spokesman Tom Aluise told ABC News.

Following a notice from the West Virginia American Water Company that its water supply had been contaminated, Gov. Earl Ray Tomblin Thursday evening issued a State of Emergency for Boone, Cabell, Clay, Jackson, Kanawha, Lincoln, Logan, Putnam and Roane counties. Several school districts are also affected by the chemical leak, including Lincoln, Queen Shoals, Reamer, City of Culloden and City of Hurrican public schools.

“West Virginians in the affected service areas are urged NOT to use tap water for drinking, cooking, washing or bathing,” Gov. Tomblin said Thursday in a statement. “Right now, our priorities are our hospitals, nursing homes, and schools. 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.”

According to Aluise, the backup system in place to prevent chemicals from leaking into the river failed, leading to the contamination of water throughout the region.

“There was a breach of that secondary containment, which is why this fluid got into the river because that containment is there to prevent this very thing from happening,” he told ABC News.

Aluise said the leak has been contained. However, officials are still trying to determine exactly how many gallons of the chemical spilled into the river.  How much MCHM was in the tank when the leak began is not yet known.

“It is probably — by now actually — most of the material is already washed downstream,” Aluise said Thursday.

The foaming agent, while not toxic, is harmful if swallowed, warns Aluise.  

Officials are unsure how long the water ban will last, but Gov. Tomblin urged residents to steer clear of the water while the incident is investigated.

“We do not know at this time exactly how long this ban will be, but just want to reemphasize, again, please do not use the water,” he said.

In the meantime, the governor advised, residents should use only bottled water. The state has contacted FEMA to supplement the affected region’s water needs.

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