The $45 million expansion of Koch Foods could bring hundreds of new jobs to Butler County as early as the fall.

The company’s chicken processing plant on Port Union Road broke ground last week on an expansion that will add 390 jobs to the facility’s current 800 jobs.

The first phase of construction is 40,000 square feet of office space along the south and west sides of the existing facility, to be completed by mid-summer, said Gary O’Donnell Jr., a production executive for United Insulated Structures Corp., which is supervising the project.

The second phase of construction involves the installation of three new production lines, which is where the bulk of the new jobs would be created, said Greg Kathman, the economic development manager for the city of Fairfield.

“We haven’t seen their plans for it yet, but that would be great if those go online this year,” he said. The new jobs pay an average of $12 to $13 an hour, he said.

New buildings, including 185,000 square feet of production, maintenance and storage areas, are part of the second phase of construction and would begin to come online in the fall, O’Donnell said.

The project also entails renovating about 70,000 square feet of the existing facility. Koch’s waste water facility would be revamped to accommodate the increase in discharge from the plant. Koch is the city’s leading water user, city officials have said.

Fairfield City Schools are set to receive $42,600 a year and Butler Tech $1,300 annually for 10 years, per the agreement with the city, which is providing a 75 percent property tax abatement. However, the schools would not start receiving that money until after the project is done, which could be as late as 2015, Kathman said.

Koch has more than 20 facilities nationwide, supplying chicken to companies that include Kroger, Steak ’n’ Shake, Sonic and Ruby Tuesday. It does business in six states, including Mississippi, Alabama, Georgia and Illinois.