I am currently building a new inground roman style pool. It is an 18 x 43 diving pool. The builder has put up the Polymer walls and poured the bottom and sides and used gravel for the back fill behind the walls. The pool concrete outside decking has not been installed yet. I noticed a day after the bottom and slope was poured with concrete that ground water was seeping into the bottom of the pool at a slow rate and various areas of the pool wall and has not stopped. We had a very hard rain this past week and the water was coming in through the seams of the Polymer walls as well as the concrete at the bottom of the pool. The builder has informed me that this is fine and not to worry about it and that when the liner is installed it should fix any issues by the pressure of the liner against those areas.
This is a big investment for me and I just see all these leaks and it makes me nervous that we are just covering up with the liner. Is this just part of it when ground water is present? He is putting a sump pump on the side of the pool by the steps which he said will keep it off the walls but I'm still concerned about all the water seeping at the concrete joints in the bottom of the pool and various areas of the walls. I appreciate any feedback you all can provide.