Drain tile systems are placed around the footings of a home to direct water away from the foundation wall and to assist in waterproofing. The absence or failure of a drain tile system creates hydrostatic pressure against the floor of floor/wall joint area. Revised building codes no longer allow drain tile systems to direct water into the city storm sewers.
Sump pumps have become very common for waterproofing and directing the water out of the sump pits to a place on the property away from the foundation walls. If the sump pump is functioning properly, the usual source for leaks are a compromised drain tile system.