Mayor Joseph Sullivan will host a discussion Tuesday on automated trash pickup in an effort to quell concerns about the new system. Automated pickup, set to begin Sept. 30, will replace existing barrels with one 64-gallon trash barrel and one 64-gallon recycling barrel. “We’ve sent out our mailing with the details and frequently asked questions about the new program, and if people have questions after receiving that and want more info, they are more than welcome to attend,” said Peter Morin, chief of staff and operations for the town. The event will be televised and rebroadcast, and customers can also call the Recycling Office at 781-794-8088 or Sunrise Scavenger’s customer service line at 617-361-8000. “There are a number of places they can get answers,” Morin said. The meeting will be held at Braintree Town Hall from 7 to 8:30 p.m.