This report presents the analysis of "data from three two-day aquifer tests of the unconfined aquifer (water-table_ aquifer in southern Nassau Count, Long Island, during the autumn of 1979.

From purpose and scope: The purpose of this report is to develop and test steady-state method for the measurement of propane-gas desorption coefficients in a natural channel flow as the first phase of the field assessments of hydrocarbon gas tracer method for reaeration coefficients. Three field tests were conducted in a straight 5.2 km reach of the Cowaselon Creek near Canastota, New York in June, July, and October, 1981.

Purpose and scope: This report describes (1) methods of computation used to obtain the daily lake inflows and outflows and river discharges; (2) sources of error and their implications for reliability of the computed values; and (3) a technique for smoothing lake-level hydrographs that minimizes the effect of random fluctuations in daily lake-levels resulting from seiche or wind action.

From purpose and scope: This report is the first in a three-part series describing the U.S. Geological Survey's efforts in the detailed hydrologic investigation of southern Nassau and southwest Suffolk Counties, which includes a ground-water modeling study to predict the effects of an extensive sewer network scheduled to be completed in 1985. As the introduction to the series, this report has four objectives: (1) to present a detailed description of the hydrologic system in the area, including newly acquired hydrogeologic information; (2) to define the hydrogeologic factors that will be affected by the sewer network; (3) to explain the modeling strategy and describe the techniques used to develop the ground-water models of the two adjacent areas studied; and (4) to present a preliminary evaluation of the effects of sewers as predicted by a regional ground-water flow model.

Purpose and scope: The Meadowbrook artificial-recharge project, a cooperative effort between the U.S. Geological Survey and the Nassau County Department of Public Works (NCDPW) since 1975, is intended to demonstrate the feasibility of using reclaimed wastewater to replenish and improve the quality of Long Island's ground water. This report presents the results of geologic, hydrologic, and hydrochemical studies that were done at the Meadowbrook artificial-recharge site to define conditions prevailing before the start of recharge operations.

Purpose and scope: This report presents results from an evaluation of geologic data collected and compiled as part of a continuing investigation and appraisal of hydrologic conditions in Suffolk County. The investigation is part of a cooperative program of water-resources studies made by the U.S. Geological Survey in cooperation with the Suffolk County Water Authority and the Suffolk County Department of Health Services.

Purpose and scope: This report depicts in detail the areal extent, altitude, thickness, and lithology of the "20-foot" clay and Gardiners Clay (the two thickest and most extensive near-surface confining layers in the area) and redefines the surface of the geologic units that directly underlie these clay units at various locations--the Matawan Group-Magothy Formation, undifferentiated, the Monmouth Group, and the Jameco Gravel.

Purpose and scope: This report discusses the design, theory of operation, performance characteristics, and sampling implications if the inclined gravity lysimeter. This variation of a gravity lysimeter can be constructed to maximize capture efficiency and eliminate artificial filtration and is used most successfully in coarse, moist soils where access for installation is from a trench or observation manhole.

From purpose and scope: This study was undertaken to evaluate the reduction in PCB concentrations in Hudson River water that occurs during treatment at the Waterford plant. The concentration of PCB's in untreated Hudson River water were compared with those in treated drinking water at Waterford, and an average removal efficiency at the treatment plant was calculated.

From purpose and scope: The main purpose of this monitoring was to gather several years of data on PCB concentrations preparatory to removal of contaminated sediments by dredging, which was originally scheduled for the early 1980's. Plans for dredging and disposal of sediments are currently being reevaluated. This report examines the contribution and transport of PCB's (polychlorinated biphenyls) from various reaches of the Hudson River and the changes in PCB concentration since 1977, when discharge was terminated.

From purpose and scope: The purpose of the study was to collect detailed water level information needed for calibration of the U.S. Geological Survey's digital computer model of ground-water flow.

Purpose and scope: The purpose of this report is to quantify the base flow of 19 continuously gaged Long Island streams during 1960-75, which includes the 1962-66 drought. These base-flow data will be used in calibrating computer models designed to predict the response of Long Island streams to hydrologic stresses such as the lowering of ground-water levels in response to large-scale sanitary sewering. The data will also be used to assess the long-term impact expected to result from storm- and sanitary-sewer systems on base flow of streams.

Purpose and scope: This report evaluates the rainfall-runoff data collected at 12 sites on 10 streams in Rockland County during 1975-79 and examines the adequacy of the rainfall-runoff models developed for 10 of the sites. The predictive capability of the models will dictate their use in eventual determinations of flood-frequency relationships at each gaged site.

Purpose and scope: This report describes the relationship between geology and ground-water occurrence in Oswego County and indicates how much ground water is likely to be available in any given area. It is a companion to a series of 29 maps produced during 1978-80^1 to document the surficial deposits in the county's 29 quadrangles and includes a compilation of data on representative wells in each quadrangle.

From purpose and scope: This report describes the interaction between river water and the river-bottom deposits above Troy and provides estimates of the yearly transport rate of PCB's from the study reach into the Hudson River estuary.

Introduction: The U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, and aided by the Susquehanna River Basin Commission, investigated the water quality of the Tioga River basin, Pennsylvania. The study, made from September 1973 to September 1978, was designed to evaluate water quality at various sites prior to impoundment. Results of the investigation will aid the Corps of Engineers in designing the operation of three reservoirs that were in the final stages of construction in late 1979.

This report evaluates six public water-supple systems in Schenectady County to create a recommendation of how to monitor these sites. It contains maps and tables.

From abstract: "Flow-routing models were developed for six reaches of major streams in the eastern Susquehanna River basin in New York State and were used to trace releases of water from East Sidney Lake and Whitney Point Lake to gaged points downstream." It includes maps, graphs, and tables.

From abstract: "Water samples from two Hudson River floods in 1977--one originating mainly in shale sub-basins that produce high sediment loads, the other in soil-poor, crystalline rock terrane that yields little sediment--were analyzed to evaluate the relationship of iron, manganese, lead, phosphorous, and polychloride biphenyle (PCB's) to suspend-sediment concentration."

Purpose and scope: This report presents results of a survey conducted in New York from 1978-80 to determine the occurrence and extent of ground-water contamination by organic chemicals and to establish whether airborne contaminants from industrial and metropolitan centers might be a factor in aquifer contamination. To these ends, 74 samples from 56 wells at 49 sites across New York State excluding Long Island1 were analyzed for the organic chemicals listed by the U.S. Environmental Protection Agency (EPA) as "priority pollutants." The general location of sites sampled is given in figure 1 (p. 26); information on wells sampled is given in table 8 (p. 27).

From abstract. This report examines flow-duration curves for nine streams in Nassau and Suffolk Counties to evaluate effects of urbanization on streamflow patterns in New York. It contains a map, graphs, and tables.

This report presents the results of a preliminary investigation into the water quality and the relationship between surface and ground-water for the Connetquot Brook basin in Long Island, New York. It contains maps, graphs, and tables.

From abstract: This report studies the covers over radioactive waste burial trenches in New York; it describes the results of "measurements of atmospheric pressure and the differential pressure between the trench gas and the atmosphere" over a two year period. It contains maps, graphs, and tables.

Abstract: A facility consisting of a circular recharge basin 6.10 meters in diameter with a central observation manhole was developed on Long Island to study the role of the unsaturated zone during aquifer recharge with tertiary-treated sewage. The manhole extends through most of the 7.5-meter-thick unsaturated zone, which is composed of glacial outwash sand and gravel, and enables collection of water samples and monitoring of dynamic characteristics of the unsaturated zone during recharge experiments. The system contains instrumentation for monitoring infiltration rate, pressure-head distribution, soil-moisture content, ground-water levels, and soil gases. The 24.55-square-meter recharge basin has operated in all seasons intermittently since April 1975 and, as of April 1978, has transmitted 62 million liters of tertiary-treated effluent to the water-table aquifer. Overall performance of the facility indicates that it is suitably designed for monitoring the unsaturated zone during artificial-recharge experiments.