FIG. 3.

Results of microbiological analyses using solid media plating. Populations cultured from the core (“attached”) are juxtaposed with populations cultured from the groundwater (“unattached”). Depth is expressed in meters (m) below land surface. BD, below detection limits; TNTC, too numerous to count. a, neither acidophilic enumeration was performed on this sample; b, no enumeration of neutrophilic anaerobes was done for this sample.