GREEN BAY, WI (WTAQ) - The city of Green Bay wants to make recycling carts mandatory use for all homeowners.  Right now around 40% of residents use the carts voluntarily. In his state of the city address, Mayor Jim Schmitt wants everyone on board by the end of the year, as part of a plan to get recycling and garbage pick-up fully automated.  Schmitt says automation will reduce injury to drivers getting out of the trucks to manually collect recyclables, increase efficiency, and reduce labor costs. Schmitt says over the last five years, the city has spent $280,000 on job related injuries among sanitation workers.Depending on what size the city chooses, which seems to be the larger 96 gallon bin, the carts would costs between $40 and $50.  The recycling carts would be billed to homeowners. The city wants to start delivering the carts by the fall.  The city council will have approve the move.