Date of Award
Doctor of Philosophy
Science Education, Mallinson Institute
Dr. W. Thomas Straw
Dr. George G. Mallinson
Dr. Richard Passero
Dr. Joseph G. Engemann
The vertical direction of ground-water flow in Austin Lake was determined by placing minipiezometers along the entire shoreline at fifty randomly selected sites. Ground-water samples were taken at each site and the specific conductivity of the water samples was determined along with the chloride and phosphate content. The data were analyzed to determine if there were any relationships among water movement, chemical content, and the presence or absence of an onshore septic tank. The minipiezometer data show that the primary direction of water movement through the sediment-water interface is downward but may become reversed at localized regions as conditions vary. The negative hydraulic differential is greater at the north and south ends of the lake than on the east and west sides. This observation makes a stronger case for reports by other researchers that Austin Lake is on the ground-water divide and that ground-water flows to the north and to the south from the lake. Computer analyses of all data show relationships among specific conductivity, chloride content, and the presence of a septic tank. Offshore from septic tanks, the specific conductivity and chloride content vary more and have higher average concentrations than offshore from areas without a septic tank, although visual inspection of the data shows pollution to be minimal. Phosphate content failed to show relationships with septic tanks, but tended to be higher on the west side of the lake--an area bounded by outwash and containing older functional and non-functional septic tanks.
Williams, William Thomas, "Ground-Water Flow Along the Total Shoreline of Austin Lake and Its Environmental Contribution to Pollution of the Lake" (1982). Dissertations. 2534.