I'm not sure if there is more than one, but we used one last week on the ground floor right near the north elevators. You had to use your room key to enter the laundry room, but the washers and dryers are free to use. There were about 3 washers and 6 or 8 dryers. They had a vending machine selling detergent and stuff, but it took exact change and the change machine was out of order. Luckily we had our own.