48 FLORIDA GEOLOGICAL SURVEY
Table 3. ANALYSES OF PESTICIDES IN WATER FROM SELECTED CANALS, DECEMBER 21,1966.
Analysis by U.S. Geological Survey
(parts per trillion)
. "o~
Snake Creek Canal above
S-29 near North Miami
Beach. 10 nd nd nd 10 nd nd 10 nd nd
Plantation Canal above
S-33. near Fort
Lauderdale. 10 nd nd nd 10 nd 20 10 10 40 Pompano Canal, above
control at Pompano
Beach. nd nd nd nd nd nd nd nd nd nd Hilsboro Canal above
control, near
Deerfield Beach. nd nd nd nd ad nd nd 10 nd nd
nd-Not detected
tank sludge was being treated in sewage-treatment plants. The Broward County Health Department required complete treatment of sewage and post-chlorination of the effluent before discharging into the receiving water. Sewage-plant effluent is generally higher in nitrates and chloride than the natural water of the area. During drought periods, when the canal control structures are closed, the increased dissolved chemical constituents in canal water caused by sewage can be further concentrated by evaporation of the canal water.
SUMMARY AND CONCLUSIONS
The chemical quality of the water in the interrelated surface and ground-water system of Broward County is generally good. Most of the water used in Broward County is obtained from the Biscayne aquifer which is recharged by local rainfall and by water that infiltrates from the canals. The very permeable limestone of the Biscayne aquifer permits relatively free interchange of water between the aquifer and the canals.
The mineral content of water from the Biscayne aquifer usually meets the water standards set by the State of Florida. The water is hard, and in the southeast part of the county it contains iron in objectionable concentrations. Ground water along the coast is contaminated by saltwater, and parts of the aquifer inland contain salty remnants of ancient sea floodings. The water contained in the major part of the aquifer is a