I have a drain in the back door well on my house that has been plugged since we bought the house. I have had a plumber out and they basically want to jack hammer my floor up to replace the pipe. This drain appears to go under the floor into the main house drain system. Is this a normal configuration for this drain. I have been told that this drain should just drop down into the drain tile around the foundation not go into the "city" sewer system. The house is a basic bi-level.