Hydrogeology and preliminary assessment of the potential for contamination of the Memphis aquifer in the Memphis area, Tennessee

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.