President Barack Obama declared a state of emergency for West Virginia on Friday after a chemical spill that contaminated the Elk River left up to 300,000 people without tap water, closed schools and businesses, Reuters reported.

The chemical leak came from the Freedom Industries coal treatment facility on Thursday outside of Charleston, West Virginia's capital and largest city. It happened upriver from the eastern U.S. state's largest water treatment plant. The federal government declared the disaster a day after state officials.

The chemical spill occurred upriver from the intake of the Kanawha Valley water treatment plant in Charleston, which serves 250,000 to 300,000 people, Laura Jordan, external affairs manager for West Virginia American Water, told Reuters.

In the wake of the leak, State Gov. Earl Ray Tomblin and health officials on Thursday advised residents to use tap water only for flushing toilets and fighting fires, Reuters reported.

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

According to WBNS-10TV, state officials say the orders were issued as a precaution. They are reportedly not sure exactly what hazard the spill pose to residents. They also do not know how long the chemical had been leaking, Tom Aluise, a state Department of Environmental Protection spokesman, told WBNS-10TV

"Our understanding is it's not an especially toxic material. It's not dangerous necessarily to be around," he said.

According to Aluise, the tank at the coal treatment facility that leaked the chemical holds at least 40,000 gallons.

"We're confident that no more than 5,000 gallons escaped," he said. "A certain amount of that got into the river. Some of that was contained."

The declaration makes federal resources available to the state. The West Virginia National Guard plans to distribute bottle drinking water to emergency services agencies in the affected counties.

Federal authorities will also launch an investigation into the circumstances surrounding the spill and what caused it, U.S. Attorney Booth Goodwin said in a statement on Friday.