Plans to design a desalination plant and launch a study to ban single-use plastic bags were approved in Santa Cruz today. The council voted unanimously to sign a design contract with a Walnut Creek firm to draft partial plans for the proposed desalination project. If approved, the plant would transform 2.5 million gallons of seawater per day, and the city would draw on the supply only during drought years. The council also approved studying a ban on plastic bags dispensed by grocery stores, eateries and merchants. The ban would charge customers 10-cents for each paper bags. The county is currently looking at a similar ordinance, as are other communities statewide after the Legislature failed to pass a statewide ban recently.