L-31N Lithological and Geophysical Data

The objectives of this data acquisition project were to provide the on-site geologic expertise while the four coreholes and the deepest well in each cluster were drilled and constructed, and to complete the downhole geophysical logging including video and flow meter logging of these boreholes. The USGS on-site geologist provided technical guidance to the drill crew, described the lithology of the core and unconsolidated sediments, and stored the cores and sediment samples for the duration of the project. USGS staff provided and ran gamma ray, fluid conductivity and temperature, EM-induction, 3-arm caliper, full wave form sonic tools, a heat-pulse flow meter, an OBI-40 Mark III digital optical tool, and the Laval video tool.

The goal of the L-31N Seepage Management Pilot Project is to reduce levee seepage that moves from Everglades National Park to the east. As participants in this pilot project, the South Florida Water Management District, the United States Army Corps of Engineers, and the United States Geological Survey worked together to provide a hydrogeologic characterization of the Surficial aquifer underlying the L-31N Levee in Miami-Dade County, Florida. Because there is little detailed hydrogeologic data of the Surficial aquifer (to depth) in this area, the L-31N Seepage Management Project Delivery Team (PDT) installed two clusters of monitor wells and four additional coreholes along the levee to provide the necessary detailed hydrogeologic data to the PDT. The L-31N project was spilt into two seperate projects, a data acquisition project and an interpretive project. The objectives of the data acquisition project was to provide the on-site geologic expertise while the four coreholes and the deepest well in each cluster were drilled and constructed, and to complete the downhole geophysical logging including video and flow meter logging of these boreholes. The objective of the data interpretation project was to provide the PDT with detailed hydrogeologic information in order to understand the movement of water in the Surficial aquifer along the L-31N levee and delineate the lithology and hydrostratigraphy of the rocks and sediments underlying the levee.