The New York State Public Service Commission has set in motion a process to address the depletion of phone numbers with the 631 area code, which is projected to occur by the first quarter of 2016, and has scheduled public hearings on alternate strategies for doing so. A public hearing before an administrative law judge will be held in Riverhead on Tuesday at the Riverhead County Center, 300 Center Drive, at 2 p.m., preceded by an informational forum at 1 p.m. Those wishing to speak need only appear.