The company responsible for pollutant chemicals leaked into a West Virginia river Thursday, sending four to the hospital and leaving 300,000 people without water, had informed state authorities in February it was storing 10 industrial chemicals on the site.

According to a document released Saturday, Freedom Industries Inc. said nearly a year ago that it was storing between 100,000 and 999,999 pounds of 4-methylcyclohexane methanol, known as MCMH, which it described as having “immediate (acute) health hazards,” the Wall Street Journal reports.

The information was also shared with a local emergency planning committee, but it was unclear whether the region’s water treatment plant was made aware of the document. A representative from the water treatment plant said the company was unfamiliar with MCMH.

A federal investigation was launched into the spill Friday.

[Wall Street Journal]