ENR cores had the largest variations in hydraulic conductivity at shallow elevations (10.6 to - 12.6 ft NGVD) as shown in table 7. The low vertical and horizontal K measurements at shallow elevations in the ENR indicate a restrictive layer or caprock, as suggested by Rohrer (1999). Although the restricting layer is common in limestone above 0 ft NGVD, it is not spatially continuous, as evidenced by many cores with K_v values higher than 1 ft/d. This discontinuous restrictive layer was observed during drilling operations at site M301. Here, the drilling fluids did not return to the surface for subsequent re-circulation, but emerged 18 ft away from the drill rig.

Core analyses found large variations in K_v in the consolidated sediments of the ENR boreholes. Less variation was seen in WCA-2A cores. A thin layer with very low K_v (0.001 - 0.1 ft/d) was found to overlie a layer of high K_h and K_v at sites MP1, MOP1, and MOP2. The elevation of these restricted flow/high flow layers varies at each site; the restrictive layer was between 5.9 and -7.5 ft NGVD and the high flow layer was between -4.6 and -15.9 ft NGVD. The layers of high hydraulic conductivity act as preferential flow paths encouraging horizontal flow because of the overlying restrictive layer. When this restricting layer is eroded or fractured, a preferential pathway for vertical transport of water and its constituents is created because the K_v is much higher than the K_h. The vertical and horizontal hydraulic conductivity and porosity for two shallow layers in ENR sites MOP1, MOP2, and MP1 are shown in table 8. The extreme differences in K_v at the different elevations at these sites can be seen clearly in table 8.

A variety of methods was used to estimate the average hydraulic conductivity of the peat. The methodology is addressed by Harvey and others (2000). In the ENR, the K of the peat is two orders of magnitude less than the K of layer 2 (table 9). In WCA-2A, the K of the peat also is appreciably less than the K of layer 2.

Properties of the core samples, such as the silica/calcium carbonate content, color, and fossil content, were used to identify the formation and Q series of the sediments. Quartz content of these four boreholes varied greatly by both site and elevation as shown in table 10. These differences indicate changing depositional environments. As stated previously, shallow water marine carbonates and siliciclastic material dominate the Quaternary and portions of the Pleistocene deposits in south Florida. The lithology of the core samples from WCA-2A sites E-1, F-1, F-4 and ENR site M-204 were described in detail in by Harvey and others (2000, p. 96-98).

South Florida Water Management District staff sorted though the sieved samples for whole and partial fossils to assist in stratigraphic correlation. Fossils were identified and logged. Because of the large number of fossil species identified, each species was assigned a numerical identification number. Preliminary descriptions are provided in Harvey and others (2000). A stratigraphic correlation was not in the scope of this study.