About 20 workers active with the Service Employees International Union Local 620 marched in a loop in front of City Hall, chanting slogans over a megaphone that pierced the council deliberations taking place within. At issue was the 11 months of negotiations between the city and union members working waste-water treatment, the water department, the waterfront, and Harbor Patrol. Union members said the 4 percent pay hike that’s been offered over the next two years pales in comparison to the wage increases offered to other bargaining units, especially police officers and firefighters. In addition, workers on the picket line complained that their out-of-pocket expenses for health care had increased dramatically — to $900 a month — in recent years. Several union activists spoke at the council meeting, as well, warning that skilled safety personnel might be forced to leave town to make ends meet.