Leachate plumes in ground water from Babylon and Islip landfills, Long Island, New York

Open-File Report 77-583




Landfills operated by the towns of Babylon and Islip in southwest and central Suffolk County, N.Y., contain urban refuse , incinerated garbage, and scavenger (cesspool) waste; some industrial refuse is deposited at the Babylon site. The Islip landfill was started in 1933, the Babylon landfill in 1947. The landfills are in contact with and discharge leachate into the highly permeable upper glacial aquifer hydraulic conductivity 190 to 500 ft/d. The aquifer is 74 feet thick at the Babylon landfill and 170 feet thick at the Islip landfill. The leachate-enriched water occupies the entire thickness of the aquifer beneath both landfills, but hydrologic boundaries retard downward migration of the plumes to deeper aquifers. The Babylon plume is 1,900 feet wide at the landfill and narrows to about 700 feet near its terminus 10,000 feet from the landfill. The Islip plume is 1,400 feet wide at the landfill and narrows to 500 feet near its terminus 5,000 feet from the landfill. Hydrochemical maps and sections show the distribution of the major chemical constituents of the plumes. The most highly leachate-enriched ground water obtained was from the Babylon site; it contained 860 mg/liter sodium, 110 mg/liter potassium, 565 mg/liter calcium, 100 mg/liter magnesium, 2,700 mg/liter bicarbonate, and 1,300 mg/liter chloride. Simulation of the movement and dispersion of the Babylon plume with a mathematical dispersion model indicated the coefficient of longitudinal dispersion to be about 60 feet squared per day and the ground-water velocity to be 1 ft/d. However, the velocity determined from the hydraulic gradient and public-supply wells in the area was 4 ft/d, which would cause a plume four times as long as that predicted by the model. (Woodard-USGS)

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Leachate plumes in ground water from Babylon and Islip landfills, Long Island, New York
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Open-File Report
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U.S. Geological Survey,
vi, 72 leaves :ill., maps (2 fold. in pocket) ;29 cm.; (141 p. - PGS)