After finally getting the new house in order I can now focus on my backyard. After mowing it for the first time I noticed the lawn in the backyard was spongy. There were a couple of chipmunk holes but not much else. After having a housewarming party last weekend everyone complained that the feet of their chairs kept sinking into the dirt and this was after a stretch of dry hot days. The house is about 75 yards from a creek but there are not issues with the water table. My neighbor told me that the previous owner had an above ground pool in the yard for years. So is it possible it is loose soil from that or do I have a more serious problem? Is there anyway to firm up the ground? I kind of broke the bank with interior renovations so I can't afford to hire someone this year. Any suggestion is welcome, thanks.