The village of Endicott, New York, and the adjacent town of Vestal have historically used groundwater from the Susquehanna River valley-fill aquifer system for municipal water supply, but parts of some aquifers in this urban area suffer from legacy contamination from varied sources. Endicott would like to identify sites distant from known contamination where productive aquifers could supply municipal wells with water that would not require intensive treatment. The distribution or geometry of aquifers within the Susquehanna River valley fill in western Endicott and northwestern Vestal are delineated in this report largely on the basis of abundant borehole data that have been compiled in a table of well records.
Early in deglaciation, meltwater deposited sand and gravel in channels within or beneath the decaying ice and as narrow terraces along the valley walls. These ice-contact deposits vary widely over short distances from clean (free of silt) and highly permeable to clogged with silt and poorly permeable, but collectively constitute the principal aquifers in Endicott and Vestal. Some ice-contact deposits form a buried ridge, deposited in a meltwater channel within the ice sheet, that approximately underlies the Susquehanna River and (or) its north bank from Endwell westward to Nanticoke Creek and has been tapped by several municipal and industrial wells. Similar but thinner ice-contact deposits discontinuously underlie the valley floor to the south in Vestal, and a smaller buried ridge of ice-contact deposits is likely beneath or west of Nanticoke Creek south of West Corners.
As deglaciation continued, a large lake developed; thick deposits of gray silt with red clay layers are continuous north of the Susquehanna River from Endwell to West Endicott, and similar deposits are present discontinuously elsewhere. Late in deglaciation, meltwater deposited highly permeable pebbly sand atop the valley fill, generally atop lacustrine silt. The saturated thickness of this surficial sand is seldom great enough to support large-capacity wells, but where it directly overlies ice-contact deposits it facilitates recharge from precipitation and infiltration of river water to the deeper aquifers.
Three localities in Endicott were identified where thick ice-contact deposits capable of supporting municipal supply wells are documented by test wells or extrapolated to be present from nearby data and depositional history. Chemical analyses of water samples disclosed no contaminants in these localities when sampled, but the presence of contaminants or natural high iron a few thousand feet away from each locality is documented.
