San Luis Obispo residents could be in for an increase in their utility bills starting this summer. City officials are considering a rate hike for sewer and water services over the next two years. They say the increases are needed to cover the costs of infrastructure improvements, maintenance, and bond financing requirements. The first hike could happen as soon as July, with a second increase next year. A public hearing about the proposed rate hikes is scheduled for June 18th in the City Council Chambers at 6 p.m…