Transport and distribution of nutrients in the Loxahatchee River estuary, Southeastern Florida, 1979 to 1981
[No abstract available]
Water Resources Bulletin↗
Geology topics
W. H. Sonntag
Publications and source records attributed to W. H. Sonntag.
Chemical characteristics of water in the surficial aquifer system, Dade County, Florida
Geohydrologic test drilling was conducted throughout Dade County to describe the chemical characteristics of water from geohydrologic units in the surficial aquifer system. Water quality analysis of samples collected from the test wells completed in central Dade County indicates that the Biscayne aquifer (unit A), the upper clastic unit of the Tamiami Formation (unit B), and parts of a limestone, sandstone, and sand unit of the Tamiami Formation (unit C) have been effectively flushed of residual seawater, and contain primarily calcium bicarbonate groundwater. The lower parts of unit C and the lower clastic unit of the Tamiami Formation (unit D) primarily contain calcium-sodium bicarbonate or sodium bicarbonate type water. An analysis of variance test indicates that water in units A and B is not significantly (0.05 probability level) different in composition. Mean concentrations of dissolved solids, sodium, and chloride are significantly different between units A and C, whereas mean concentrations of dissolved solids, calcium, sodium, and chloride are significantly different between units A and D. Groundwater in the surficial aquifer system in northwestern Dade County is more mineralized than groundwater that occurs elsewhere in the county (except in coastal areas affected by saltwater). An analysis of variance test indicates that mean concentrations of dissolved solids, sodium, and chloride at sites in northwestern Dade County, developed in units A and C, are significantly different from the mean concentrations of these constituents at sites throughout the rest of the county. Water in this part of the surficial aquifer system is similar to highly mineralized water found in western Broward County. However, in northwestern Dade County, the groundwater has been diluted to a greater extent by less mineralized recharge water. Overall, groundwater in the four major geohydrologic units of the surficial aquifer system of Dade County is suitable for most uses. Maximum concentrations of sodium, chloride, color, fluoride, iron, and dissolved solids in some areas of Dade County, however, exceed maximum contaminant levels established by the Florida Primary and Secondary Drinking Water Regulations standards. (Author 's abstract)
Florida↗
Fouling community of the Loxahatchee River estuary, Florida, 1980-81
Monthly growth of the fouling community at eight test panel sites in the Loxahatchee River Estuary was related to salinity and temperature. Growth was lowest in January 1981 (averaging 23 g per m 2 , dry weight), and increased during spring and early summer with increasing water temperature. Maximum growth occurred during early or midsummer at upstream locations, before river or canal discharge substantially reduced salinity, and in late summer at downstream locations. Growth was greatest at salinities slightly less than that of seawater and decreased at salinities less than about 10‰. Growth was suppressed throughout the estuary in August 1981, probably because of the sudden decrease in temperature and salinity, and perhaps the increase in physical scouring, caused by runoff from Tropical Storm Dennis. Large loads of nutrients transported to the estuary from storm runoff, however, may have subsequently stimulated growth, which increased in September 1981 to the maximum for the year (averaging 683 g per m 2 , dry weight).
Florida↗
Subsurface storage of freshwater in south Florida; evaluation of surface-water discharge data at selected sites
Canal discharge in south Florida may consist of a potential source of freshwater for deep-well injection. Discharge data for the 1970-81 water years at 27 canal and river sites were analyzed. Flow was analyzed for 30-, 60-, 90-, 120-, and 183-consecutive-day low-mean discharges during the periods of highest flow to define minimum high-flow-period fresh surface-water discharges at the 27 sites. Curves show the magnitude and frequency of average minimum flows for consecutive-day periods during high-flow periods, and duration curves and tables show the percentage of time that selected discharges were equaled or exceeded. Canal discharge as high as 660 cubic feet per second occurred 70 percent of the time during the high-flow period at one site (Tamiami Canal Outlets, Levee 67A to 40-Mile Bend). At 11 sites, discharges of 110 to 370 cubic feet per second occurred 70 percent of the high-flow periods, while at 9 sites, discharges of 21 to 100 cubic feet per second occurred 70 percent of the time during the high-flow periods. At other sites (those in the Biscayne, Plantation Road, Middle River, C-111, and Cypress Creek Canals), discharges as low as 0.1 cubic foot per second occurred 70 percent of the time during the high-flow periods. Criteria for amounts of surplus freshwater considered adequate to support injection systems cannot be established, as they would vary greatly with water needs to be satisfied and with the efficiency of a particular injection system. However, based upon this analysis of discharge at 27 canal and river sites throughout south Florida, it appears that substantial amounts of water are available for surface injection and storage. (USGS)
Water-Resources Investigations Report↗
Nutrient input from the Loxahatchee River Environmental Control District sewage-treatment plant to the Loxahatchee River Estuary, southeastern Florida
Two test discharges of treated-sewage effluent were made to the Loxahatchee River in February and September 1981 from the ENCON sewage-treatment plant to document nutrient loading and downstream transport of the effluent to the estuary under maximum daily discharge allowable by law (4 million gallons per day). Concentrations of total nitrogen in the effluent exceeded background concentrations by as much as 7 times during the February test, while concentrations of total phosphorus exceeded background concentrations by as much as 112 times during the September test. The effluent was transported downstream to the estuary in less than 24 hours. Discharge of treated sewage effluent to the river-estuary system in the 1981 water year accounted for less than 0.5 percent of the total nitrogen and 8 percent of the total phosphorus discharged from the major tributaries to the estuary. If maximum discharges of effluent (4 million gallons per day) were sustained throughout the year, annual nitrogen loading from the effluent would account for 5 to 18 percent of the total nitrogen input by the major tributaries to the estuary. With maximum discharges of effluent, annual phosphorus loading would exceed the amount of phosphorus input by the major tributaries to the estuary by 54 to 167 percent. (USGS)
Florida↗