Citing a need to quickly pick a location for a new state health exchange call center, Contra Costa County supervisors will hold an emergency meeting Friday.

The board will choose between two proposals, one in Richmond and the other in Concord.

Both communities are lobbying for their sites, but the county has been hung up for weeks on labor negotiations. The county finally got a deal Wednesday with the fourth and final union that will represent the new workers.

The county-run call center and its 205 employees will enroll Californians in health insurance as required under the federal Affordable Care Act.

The public hearing will start at 4 p.m. at the board's chamber, 651 Pine St., Martinez.

Much of the deliberation will take place in closed session under real estate negotiations, as allowed under state law. But public testimony will be taken, and the vote must be made public.