Detailed maps of the thickness of the Jackson-upper Claibome confining unit and the altitude of the water table in the alluvium andfluvial deposits provide much new information concerning areas where downward leakage is or may be occurringfrom the water-table aquifers to theMemphrj aqutyer in the Memphis area. A detailed map of the altitude of the potentiometric surface of the Memphis aquifer and the locations of 44sites where contaminants have been detected in the water-table aquifers indicate that many of these sites are located in areas where the direction of ground-water flow in the Memphis aquifer is toward municipal well fields. Consequently, if contaminants enter the Memphis aquifer, a hydraulic potential exists for their transport to those wellfields. Recently (19&S-88), volatile organic compounds were detected in water from five municipal wells screened in the Memphis aquifer - three in the Allen well field of the Memphis Light, Gas and Water Division at Memphis and two in the west well field at Collierville. Concentrations of seven volatile organic compounds totaled about II microgramsperliterin asamplefrom one well in theAllen wellfield at Memphis, and the concentration of one compound was 25 micrograms per liter in a sample j?om one well at Collierville. These are the first reported occurrences of synthetic organic compounds in the Memphis aquifer andprove that the principal aquifer in the Memphis area is vulnerable to contamination.