Progress report on studies of salt-water encroachment on Long Island, New York, 1953

Open-File Report 54-176
Prepared in cooperation with the Nassau County Department of Public Works, New York State Water Power and Control Commission, Suffolk County Board of Supervisors, and the Suffolk County Water Authority
By:  and 



Nearly all the water used on Long Island, N. Y., is derived by wells from the thick and extensive water-bearing formations that underlie and compose the entire island. The unconsolidated deposits, consisting of sand, gravel, and clay, range in thickness from a few feet in northern Queens County to more than 2,000 feet in southern Suffolk County. Four main and relatively distinct aquifers, all interconnected hydraulically to a greater or lesser degree, have been recognized and delineated at least in a general way. They are, from younger to older, the upper Pleistocene deposits, in which the ground water is mainly unconfined, and three formations in which the water is generally confined - the Jameco gravel, of Pleistocene age, and the Magothy (?) formation and the Lloyd sand member of the Rartian formation, both of Lake Cretaceous age. Except for some artificial recharge, these aquifers are replenished entirely by infiltration of precipitation. Under natural conditions, the fresh water moves into and through the formations, discharging into the sea.

With the growth of population on Long Island and the continuously increasing use of water over the years, not only has the infiltration of precipitation been seriously impeded at places, but the withdrawals from the ground-water reservoir have increased markedly. These factors have upset the natural balance between the fresh surface and ground water of the island and the surrounding sea water, and with increased use of water will do so more and more, thus leading to salt-water encroachment. In a sense, the whole problem of utilization of ground water on Long Island is one of determining how much ground water can be withdrawn without serious salt-water encroachment.

Study Area

Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Progress report on studies of salt-water encroachment on Long Island, New York, 1953
Series title Open-File Report
Series number 54-176
DOI 10.3133/ofr54176
Year Published 1954
Language English
Publisher U.S. Geological Survey
Publisher location Mineola, NY
Description 7 p.
Country United States
State New York
City Long Island
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