Answer:
The meaning of the dream depends on whether the house is your own house in the dream, or if you knew the house belonged to somebody else. If it is your own house, then the house represents your life, and the water beneath it indicates that your life does not have a firm, steady, dependable foundation. The cesspool (cesspit) suggests that there are dirty secrets in your past that are polluting the foundation on which you have tried to build your life.
For example, a certain man falsely claimed to having an advanced engineering degree from a prestigious graduate school. Although he built a successful career, when his deception was found out, he lost his job and no longer had any respect among his peers. He had built his life on a lie, which a dream might represent as a cesspool underneath a house.