The city council is scheduled to hold a public hearing on April 14 to consider establishing a reinvestment zone at the location. The company, which is among the top 10 employers in Arlington according to the city’s website, will spend $307 million on the physical expansion and $986 million on new equipment. “GM is developing a business case for a potential future investment at Arlington Assembly. We cannot share details at this time,” GM spokeswoman Jennie Ecclestone said in an emailed statement.