The company closed on the $180 million purchase of the refinery in Trainer and a union official said workers are expected to start returning and getting the plant ready next week.
"Finally, and fortunately, the deal was done," said Denis Stephano, president of the local steelworkers union, who represents about 220 workers at the plant. "We're looking forward to going back to work."
In April, Delta announced plans to buy the idled ConocoPhillips refinery. ConocoPhillips shut down operations at the facility in the fall and threatened to close the facility if a buyer wasn't found by the end of May.
Officials said the refinery is expected to restart in September and that a Delta subsidiary - Monroe Energy LLC - will run it. Monroe will start a turnaround at Trainer after the July 4 holiday and plans to resume fuel production in the fall, company officials said in a statement.
"We have a team of refining experts and proven leaders effectively implementing our strategy at the Trainer Refinery," said Jeffrey Warmann, chief executive officer and president of Monroe Energy. "We are eager to start the work before us and humbled by this opportunity to make a difference in this community."
The company has said it expects to have about 400 workers at the plant. Stephano said nearly all of the workers who wanted to return to work at the facility will be able to do so.
Workers will begin returning next week for orientation and training, he said. Over the next 50 to 60 days they will be doing maintenance work and getting ready to resume production.
The closing comes a day after state regulators approved a pipeline transfer that was part of Delta's plans to buy the refinery.