Gene Shinn (retired) Chris Reich; Don Hickey; Ann Tihansky, 2005, Groundwater Seepage data (Florida Keys).Online Links:
Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in Decimal degrees.
The horizontal datum used is WGS84.
The ellipsoid used is WGS84.
The semi-major axis of the ellipsoid used is 6378137.
The flattening of the ellipsoid used is 1/298.257223563.
727 803-8747 ext 3032 (voice)
727 803-2032 (FAX)
creich@usgs.gov
Treated sewage is injected into the limestone under the Florida Keys via on-site disposal systems (OSDs). There are 25,000 septic tank systems, approximately 5,000 cesspools, and approximately 1000 class 5 injection wells. Depths of injection wells ranges from 10 to 30 meters. Excessive algal growth, coral diseases and both marine grass and sponge mortality is perceived by the local population, NOAA, and EPA to be caused by sewage nutrients leaking from groundwater on both sides of the Florida Keys. Determining the rate and direction of saline groundwater movement beneath the Key, and the Florida Bay was considered critical to understanding the fate and effects of subsurface waste water disposal n the Florida Keys.The objective of this research was to determine the rate, direction of flow, and contamination levels of saline groundwater in the Florida Keys and Florida Bay. Contamination studies are necessary to determine if nutrient and other contaminant levels are rising and to provide a baseline of data for future decision making.
For the seepage meter experiment in south Florida (Florida Bay, Florida Keys) a new design of seepage meters was developed. A fiberglass mold (~70cm x 70cm) was constructed from an off-the-shelf household skylight. Approximately 60 seepage domes were constructed and installed at various locations throughout the study region. Because the study regions underlying Pleistocene limestone is very heterogeneous several domes were installed in certain locations to combat hydrogeologic variations which control flow in and out of the subsurface. The fiberglass seepage meter provided a rigid frame which was then mounted to the bare rock seafloor throughout Florida Bay and along the Keys. Portland cement was mixed and used to seal the edges of the fiberglass domes. A hole was previously cut in the dome top to be used for connecting a plastic bag: the preferred bag was a turkey basting bag because of its construction material.
Seepage Meter Flux Measurements:
After domes were in place and the cement had cured, basting bags were placed on domes. These bags were left on the dome for a 24hr period and subsequently removed and the volume in the bag measured with a calibrated graduated cylinder. Knowing the volume over the 24 hour period and the area of the seepage meter a flux (L/m2/d) could be calculated. These measurements were recorded and placed in spreadsheets to determine variations by location and other environmental factors (i.e., rain, tide, and wave).
Person who carried out this activity:
727 803-8747 ext 3032 (voice)
727 803-2032 (FAX)
creich@usgs.gov
Shinn, E. A. Reese, R. S.; Reich, C. D., 1994, Fate and pathways of injection-well effluent in the Florida Keys: USGS Open-File Report 94-276, U. S. Geological Survey, Florida.Online Links:
Reich, C. D., 1996, Diver-operated manometer: a simple device for measuring hydraulic head in underwater wells: Journal of Sedimentary Rresearch v. 66 n. 5, S E P M Society for Sedimentary Research, Tulsa, OK.
Halley, R. B. Vacher, H. L.; Shinn, E. A., 1997, Geology and Hydrogeology of the Florida Keys: Developments in Sedimentology Geology and hydrogeology of carbonate islands, Elsevier Science B. V., Doorwerth, The Netherlands.Online Links:
Paul, J. H. Rose, J. B.; Brown, J.; Shi, 1995, Viral tracer studies indicate contamination of marine waters by sewage disposal practices in Key Largo, Florida: Applied and Environmental Microbiology v. 61, n. 6, American Society for Microbiology, Washington, DC.Online Links:
Paul, J. H. Rose, J. B.; Jiang, S.; Kel, 1995, Occurrence of fecal indicator bacteria in surface waters and the subsurface aquifer in Key Largo, Florida: Applied and Environmental Microbiology v. 61, n. 6, American Society for Microbiology, Washington, DC.Online Links:
Benchmarks were installed onshore on both sides of Key Largo and position and elevation determined using GPS_Military P-code enabled. Two wells at each cluster were later leveled in using the benchmarks as a reference point.
Data from all 50 seepage domes were used to calculate the flux
The same tests were made at all seepage domes
Are there legal restrictions on access or use of the data?
- Access_Constraints: none
- Use_Constraints: none
727 803-8747 ext 3028 (voice)
727 803-2030 (FAX)
hhenkel@usgs.gov
Groundwater Seepage
No warrantees are implied or explicit for the data
| Data format: | contains information and data collected during the seepage meter experiments along the Florida Keys on both the Florida Bay and Atlantic Ocean sides in format MS Excel (version unknown) Size: 0.088 |
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| Network links: |
<http://sofia.usgs.gov/exchange/shinn/> |
727 803-8747 ext 3028 (voice)
727 803-2030 (FAX)
sofia-metadata@usgs.gov
U.S. Department of the Interior, U.S. Geological Survey
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