Aquifer Appraisal at the Tunison Laboratory of Aquatic Science, Cortland, New York Active

Problem - The Ithaca Subdistrict Office of the U.S. Geological Survey (USGS) is providing technical assistance to the USGS, Biological Resources Division (BRD), at the Tunison Laboratory of Aquatic Science (TLAS) in an investigation of the availability of fresh ground water. An expansion in the water supply at the laboratory is needed for a proposed spawning facility for salmon strains that are viable for natural fisheries in the Great Lakes region. The hydrogeology of the area is a complex of moraine and outwash deposits west of Cortland, N.Y. Data from existing wells at the laboratory indicate that well screens may readily clog from precipitated minerals. A review of the hydrogeology of the area, including the water quality, is needed to adequately identify potential water supply of adequate quantity and quality for the future expansion of fish production.

Objectives - Determine the hydrogeology of the moraine area within the TLAS facility and the availability and quality of ground water that may be available for the facility to use for fish production. The project area is the TLAS and in the nearby areas to determine aquifer geometry and characteristics.

Approach - An inventory of data from wells in the area was conducted to help determine the extent and geometry of aquifers. An analysis of existing aquifer-test data for the production wells and additional tests of any new wells drilled was also conducted to determine hydraulic properties and to estimate the possibility of well interference. Borehole-geophysical logging and 2-D resistivity surveys was used to help determine aquifer geometry. Water-quality samples for inorganic ions and nutrients for were taken from existing wells; additionally, chlorofluorocarbons (CFC), dissolved gas, sulfurhexafluoride (SF6), and methane (CH4) constituents were sampled at two production wells to help determine the age of ground-water flowing to these wells that and the general areas of recharge to the wells. A temporary gage was installed on the small stream at the facility to estimate flow from springs that contribute to this stream. A test well and new production well were drilled, and USGS hydrogeologists have determined that the yield and water quality for the new well will meet the water needs for the expansion in fisheries research at the facility.

Benefits - Understanding the hydrogeology and aquifer geometry in this complex moraine area will help identify quantity and quality of ground water for enhanced fish production. Additionally, the data collected and aquifer analyses performed will provide advancements in the knowledge of (1) the regional hydrologic system, especially for moraine areas where there usually is relatively little data, and (2) the hydrologic processes in moraine areas and the problems of decreased well capacity by biologic or chemical agents.

Project Location by County

Cortland County, NY