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Research about Dade County, Florida

Source-linked reports with geographic coverage including Dade County, Florida.

25 records · Page 2Linked to original sources
USGS1978

Effects of bottom sediments on infiltration from the Miami and tributary canals to the Biscayne aquifer Dade County, Florida

Infiltration from the Miami Canal and its tributaries is an important source of recharge to the Biscayne aquifer in the vicinity of the Miami Springs-Hialeah well fields. Estimates of pumpage contributed by canal infiltration decreased from nearly 100 percent in the late 1940 's to 50 percent in May 1973 while well field pumpage increased from less than 50 Mgal/d to 120 Mgal/d. As increased withdrawals enlarge the well field 's cone of depression, the threat of saltwater intrusion during dry periods has been increased. Data on water quality, water levels, and canal bottom sediments indicate that sediments greatly impede infiltration from the canals in the areas most affected by pumping. Bottom sediments reduce coliform bacteria, pesticides, PCB, metals, and other suspended materials infiltrating canal water.

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USGS1978

Ground-water quality near the northwest 58th Street solid-waste disposal facility, Dade County, Florida

The Northwest 58th Street solid-waste disposal facility, 3 miles west of a major Dade County municipal water-supply well field, overlays the Biscayne aquifer, a permeable, solution-riddled limestone which transmits leachates eastward at a calculated rate of 2.9 feet per day. A discrete, identifiable leachate plume has been recognized under and downgradient from the waste disposal facility. Concentrations of sodium, ammonia, and dissolved solids decreased with depth beneath the disposal area and downgradient in response to an advective and convective dispersion. At a distance of about one-half downgradient, the rate of contribution of leachate from the source to the leading edge of the plume was about equal to the rate of loss of leachate from the leading edge of the plume by diffusion and dilution by rainfall infiltration during the period August 1973 - July 1975. Heavy metals and pesticides are filtered, adsorbed by aquifer materials, or are precipitated near the disposal area. (Woodard-USGS)

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USGS1975

Ground-water quality in selected areas serviced by septic tanks, Dade County, Florida

During 1971-74, the U.S. Geological Survey investigated the chemical, physical, bacteriological, and virological characteristics of the ground water in five selected areas serviced by septic tanks in Dade County, Florida. Periodic water samples were collected from multiple-depth groups of monitor wells ranging in depth from 10 to 60 ft at each of the five areas. Analyses of ground water from base-line water-quality wells in inland areas remote from urban development indicated that the ground water is naturally high in organic nitrogen, ammonia, organic carbon and chemical oxygen demand. Some enrichment of ground water with sodium provided a possible key to differentiating septic-tank effluent from other urban ground-water contaminant sources. High ammonia nitrogen, phosphorus, and the repetitive detection of fecal coliform bacteria were characteristic of two 10-foot monitor wells that consistently indicated the presence of septic-tank effluent in ground water. Dispersion, dilution, and various chemical processes have presumably prevented accumulation of septic-tank effluent at depths greater than 20 ft, as indicated by the 65 types of water analyses used in the investigation. Fecal coliform bacteria were present on one or two occasions in many monitor wells but the highest concentration, 1,600 colonies/100 ml, was related to storm-water infiltration rather than septic-tank discharge. Areal variations in the composition and the hydraulic conductivity of the sand and limestone aquifer had the most noticeable influence on the overall ground-water quality. The ground water in the more permeable limestone in south Dade County near Homestead contained low concentrations of septic-tank related constituents, but higher concentrations of dissolved sulfate and nitrate. The ground water in north Dade County, where the aquifer is less permeable, contained the highest dissolved iron, manganese, COD, and organic carbon.

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USGS1974

Effects of septic tank effluent on ground-water quality, Dade County, Florida: an interim report

At each of five sites in Dade County, where individual (residence) septic tanks have been in operation for at least 15 years and where septic tank concentration is less than 5 per acre, a drainfield site was selected for investigation to determine the effects of septic tank effluent on the quality of the water in the Biscayne Aquifer. At each site two sets of multiple depth wells were drilled. The upgradient wells adjacent to the drainfields in most places, were constructed in such a way that the aquifer could be sampled at 10, 20, 30, 40, and 60 feet below land surface. The down-gradient wells at each site are 35 feet or more from the up-gradient wells in the direction of ground-water flow, and allow. the aquifer to be sampled at various depths. Except at one site, no fecal coliforms were found below the 10-foot depth. Total coliforms exceeded a count of one colony per ml at the 60- foot depth at two sites. At one site a fecal streptococci count of 53 colonies per ml was found at the 60-foot depth and at another a count of seven colonies was found at the 40-foot depth. The three types of bacteria occur in higher concentration in the northern areas of the county than in the south. Bacteria concentrations were also higher where the septic tanks were more concentrated.

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USGS1973

Resource and land information for south Dade County, Florida

South Dade County, at the southeast corner of Florida, exemplifies many of the environmental concerns that have developed throughout the United States. Considerable environmental information has recently been assembled from this region, and some of it is presented in this experimental report in folio form.

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USGS1973

Reconnaissance of the water resources in the vicinity of proposed deep-well injection sites in southeast Dade County, Florida

Deep-well injection has been selected by the Dade County Water and Sewer Authority as a means of disposing treated waste water in southeast Dade County. Preliminary plans call for the construction of a county-owned sanitary sewage treatment plant and several 3,000-foot deep injection wells at 1,000-foot intervals on Levee 31E. As a first stage, drilling of seven wells, capable of accepting, in the aggregate, 30 mgd (million gallons per day) of treated liquid waste, is planned. The locations of the proposed sites (fig. 1) were selected by the consultants for the Authority. A reconnaissance was made in the vicinity of the proposed well sites to determine the chloride content of surface and ground water because this information is needed to formulate plans for the safe disposal of salt water during drilling and testing of the injection wells. The reconnaissance was part of a cooperative program with the Dade County Water and Sewer Authority to investigate the hydrologic effects of injecting treated waste water into a deep-saline aquifer. The area of investigation is near Cutler Ridge in southeast Dade County. It occupies about 51/2 square miles bounded on the east by S.W. 77th Avenue extended, on the west by S.W. 97th Avenue, on the south by Coconut Palm Drive, and on the north by Old Cutler Road (fig. 1). The area for the investigation was selected by the Authority and their consultants.

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