Originally posted by: Googer
EDIT: I should also add, the concrete encasement is watertight or it would not have been able to hold three or four feet of standing water. The problem most likely lies in a small crack that may have developed somewhere where in seal where the lid meets the encasement.
This isn't necessarily true.
As long as the water table is high enough, it will fill up with water. Some parts of the country can't have basements because the water table is only a few feet deep and the basement would fill up with water.