Groundwater quality characteristics of the Biscayne aquifer from September 1978 through June 1979 were determined for seven land use areas within the East Everglades in Dade County, Florida. Four agricultural areas, two low-density residential areas, and Chekika Hammock State Park were investigated. The effects of land use on the groundwater were minimal in all areas; only iron , which occurs naturally in high concentrations in the Everglades, exceeded potable groundwater standards. Potassium and nitrate concentrations in certain samples increased over background concentrations in the agricultural areas. Groundwater at Chekika Hammock State Park and at a citrus grove is contaminated by brackish water flowing from an artesian well. The soil at the agricultural areas had higher concentrations of chromium, copper, and manganese than at the two residential areas or at Chekika Hammock State Park. One residential area (Coopertown) had the highest concentrations of lead and zinc and detectable polychlorinated biphenyls. Chlorinated-hydrocarbon insecticide residues in soil at three agricultural areas were higher than background concentrations. (Author 's abstract)
