original: It has been suggested that Vättern is the largest body of potable water in the world.
simplifications: Vättern is believed to be the largest body of drinkable water in the world. It's believed, Vättern is the world's largest body of potable water. Many support that Vättern is the biggest body of potable water worldwide. Vättern might be the largest body of potable water in the world. Vättern may be the largest body of potable water in the world. Vättern is believed to be the biggest body of drinkable water in the world. Some say that Vattern is the largest body of drinkable water in the world. Vättern is the largest body of potable water in the world. It was suggested that Vättern is the largest body of potable water in the world. Vättern has been suggested to be the world's largest body of potable water.