Pumping test at Levittown, Nassau County, New York, September 16-18, 1949

Abstract

This report presents and discusses the quantitative and qualitative data obtained during a pumping test at the Levittown housing development in Nassau County, N. Y. One of the ten principal supply wells, screened in the sands of the Magothy (?) formation which is overlain unconformably by the sand and gravel of the upper Pleistocene deposits, was pumped for more than 24 hours at a rate of 790 gallons per minute. During this time the develop ment of the cone of depression extended a distance of more than 1,000 feet from the pumping well. A coefficient of transmissibility of 245,0W gallons per day per foot was computed and a coefficient of storage of 0.13 was de termined at the site of the pumping test. The qualitative results show that the two aquifers at the pumping-test site, that is, the sand and gravel of the upper Pleistocene deposits and the underlying sands of the Magothy (?) formation, function essentially as one hydrologic unit. Such information, together with other data of this kind, assumes importance when it is realized that the New York rater Power and Control Commission by regulation considers every aquifer as a separate and distinct hydrologic unit. It thus requires the return of water pumped for cooling and other similar uses to the same aquifer from which the water taken, unless sufficient evidence is obtained to show that two adjacent aquifers function as a single hydrologic unit. Sufficient data were obtained during the test to suggest that perhaps about 14 feet of the 19.7 feet measured as drawdown in the pumped well is attributable to well and screen losses.