Hi! We started digging out the pool this week and have found some interesting plumbing. It is an octagon pool. As you walkl down the stairs there are returns on both sides, on different steps. They have pipes running up to the sidewalk that have been cut off. We were ale to hold our fingers on the pipes and run air in it to find where the pump sat so they are tied in to the plumbing. There is a regular return on down in the pool. What are these stair returns for?