FARMINGTON — State officials said Wednesday the 2,000 gallons of caustic liquid that spilled into the Sandy River when a tractor-trailer overturned on Route 2 would not harm the environment.

“Most of it was contained to a drainage creek that leads into the Sandy River and we were able to dike up the mouth of it,” said Frank Gehrling, an oil and hazardous materials specialist with the Department of Environmental Protection.

Gehrling said alkaline corrosive known as black liquor neutralizes quickly in water, so there was “minimal damage” to aquatic life in the river or in the creek.

About 100 people evacuated their homes and businesses for several hours because of fumes after the spill Wednesday. The driver of the vehicle, Rheal Savoie of New Brunswick was taken to Mid-Maine Medical Center in Waterville with head injuries.

He was listed in fair condition in the intensive care unit Thursday.

The vehicle, which was bound for Boise Cascade in Rumford, was carrying 6,000 gallons of black liquor, which is used to soften wood chips.

“It was a major spill with a major problem, but it was dealt with and contained,” Gehrling said, adding that the “raw product was very caustic and also very hot.”

Gehrling said that the river had been cleaned and that the rest of the contaminated soil along the river bank would be removed Thursday.

The recovered chemical will be sent to International Paper Co. in Jay to be recycled, he said.