union workers at the Constellium aluminum rolling facility in Ravenswood begin voting on a new contract today. It would mean they would begin paying 15 percent of their health-care costs. company CEO Kyle Lorentzen says each employee should see a net gain of about $15,000, including increases in wages and pension benefits, over the five years of the contract. Today, Constellium's rolling mill is the largest private employer in Jackson County. The plant has nearly 1,000 employees, 700 of whom are production and maintenance workers and members of the United Steelworkers of America. Results may be announced on Saturday. Company and union representatives have been negotiating the contract since May.