PIERRE, S.D. — The South Dakota Supreme Court has removed the final obstacle for a $150 million ethanol plant in Sully County.

Justices this week denied the appeal of 11 Onida-area residents who oppose the plant’s location, according to the Capital Journal and KCCR radio.

The neighbors had sued, saying county officials improperly rezoned the site for commercial agriculture processing to make way for the plant.

The county maintained the argument was technical and lacked substance, and a state district judge late last year affirmed the zoning decision.

Opponents then appealed to the state Supreme Court. Justices did not rule on the merits of their argument, instead saying that the opponents didn’t file their appeal within a 30-day window set in state law.

Ringneck Energy & Feed LLC this month also received an air quality permit from the state, according to President and CEO Walt Wendland.

“We are hopeful by the end of October we can see our way to get started with full construction,” he said.

It will take a little over a year to build the plant, which will produce 70 million gallons of ethanol fuel annually from about 25 million bushels of corn grown in the region. The plant will employ about 40 people.