Geohydrology and Water Quality of the Northern and Central Parts of the Tug Hill Glacial Aquifer, Jefferson and Oswego Counties, North Central New York

Problem - The entire Tug Hill glacial aquifer is a 47-mile-long, crescent-shaped mixture of glacial deposits of predominantly sand and gravel on the western side of the Tug Hill Plateau in Jefferson, Oswego, and Oneida Counties in north central New York. The Tug Hill aquifer can be divided into three parts (northern, central, and southern) based on geohydrological setting, depositional history, and type of glacial deposits (fig. 1). In this study, the name “Tug Hill glacial aquifer” refers only to the 29-mi-long northern and central parts of the Tug Hill aquifer. (The southern part was not included in this investigation.)

For this study, the division between the northern and central parts of the aquifer was placed about 0.5 miles (mi) south of the Villages of Sandy Creek and Lacona, N.Y., in Oswego County (fig. 1). The division between the central and southern parts of the aquifer is the surface-water divide between the Salmon River basin, which drains westward into Lake Ontario, and the West Branch Fish Creek basin, which drains southward into the Mohawk River.

In 2006, the U.S. Environmental Protection Agency (EPA) designated the northern part of the Tug Hill glacial aquifer and its watershed that extends eastward onto the Tug Hill Plateau (fig. 1) as a Federal Sole Source Aquifer for Drinking Water. A Sole Source Aquifer is where the aquifer supplies at least 50 percent of the drinking water consumed in the area overlying the aquifer and there are no reasonably available alternative drinking water sources should the aquifer become contaminated (U.S. Environmental Protection Agency, 2019). The Tug Hill glacial aquifer is the source of drinking water for many municipalities, as well as for drinking-water wells for private residences, mobile-home parks, campgrounds, and other facilities. Water from the aquifer is also used in manufacturing, industry, and agriculture. Additionally, the aquifer is tapped by large pumping wells that supply water to the New York State Department of Environmental Conservation (NYSDEC) Fish Hatchery in the Hamlet of Altmar, N.Y.

Development that might affect groundwater resources has been incremental over time, punctuated by a few large industries that established their manufacturing facilities near the Village of Pulaski, New York, in the mid-1960s; a landfill in the Town of Rodman, New York, which began operations in the 1980s; and residential-housing booms caused by the expansion of the military base at Fort Drum near the City of Watertown, N.Y., in the late 1980s and in 2015 (Malinowski, Tug Hill Commission, written commun., 2007). In 2007, because of concerns about the potential effects of these developments on the Tug Hill glacial aquifer, the Tug Hill Commission (THC) received requests from local officials and agencies in the region for information about the aquifer’s characteristics, capacity, and interaction with surface water.

Objectives - Improve the understanding of the hydrogeology of the Tug Hill glacial aquifer in Jefferson and Oswego counties and to provide the following information: (1) extent and thickness of hydrogeology units, (2) hydraulic properties of the aquifer, (3) extent of groundwater/surface water interaction, especially in prime Salmonid fishery areas, (4) groundwater use (type and amount of groundwater withdrawal), (5) water levels and the direction of groundwater flow, and (6) general water quality of groundwater and of streams under baseflow conditions when most water is from groundwater discharge.

Approach - This study provides a regional appraisal of the geohydrology and water quality of the northern and central parts of the Tug Hill glacial aquifer in Jefferson and Oswego Counties. The study describes the geometry and glacial origin of the northern and central parts of the Tug Hill glacial aquifer, sources of recharge and discharge to those areas, groundwater withdrawals, groundwater-flow directions, and groundwater and surface-water quality. Maps show the (1) northern and central aquifer boundaries, well locations, water levels, and selected geohydrologic sections; (2) generalized bedrock and surficial geology; (3) regional potentiometric-surface altitudes and directions of groundwater flow in the unconfined aquifer; and (4) gains and losses of waterflow in selected streams. Groundwater-withdrawal rates, water-quality analyses, and a data release of selected well data are also included in the report.

Benefits - Understanding the hydrogeology and aquifer geometry in this unique aquifer system will provide local government, water managers, businesses, and homeowners with surface- and groundwater information needed to ensure that there will be (1) a safe drinking-water supply, (2) water available for economic development, and (3) healthy aquatic environments in the future. The study will additionally build upon the USGS data collection efforts in the state and on the interpretation of the Nation’s water availability.

References

U.S. Environmental Protection Agency, 2019, Overview of the drinking water sole source aquifer program: U.S. Environmental Protection Agency web page, accessed March 20, 2019, at https://www.epa.gov/dwssa/overview-drinking-water-sole-source-aquifer-program.

Project Location by County

Jefferson County, NY, Oswego County, NY, Oneida County, NY