Hydrogeologic data were collected from Graces Quarters, Aberdeen Proving Ground, Maryland, as part of a hydrogeologic assessment begun in 1986 to determine the potential environmental effects of military testing and disposal. The U.S. Army conducted chemical-agent and munitions tests in this area from the late 1940's to 1972. This report includes a description of the well network, lithologic, and hydrologic data collected on or near Graces Quarters from April 1987 through April 1989. Observation-well network data include information used for well placement, location and construction data for 32 wells on Graces Quarters, and an inventory of 44 offsite wells. Lithologic data consist of lithologic and geophysical logs and analyses of the physical properties of core sediments. Hydrologic data collected from October 1987 through April 1989 include tables of synoptic measurements and continuous records of groundwater levels, as well as pumpage, aquifer-test, tidal, and precipitation data.) Identify the locations and dimensions of SWMU's and chemical-agent test sites, 2) define the hydrogeologic system, and 3) verify whether SWMU's in the study area have released or are still releasing chemicals into the environment and whether there is residual contamination from chemical-agent testing activities in the study area. Whether or not phase II of the hydrogeologic assessment will be implemented is contingent on the results from phase I. The objectives of phase II of the hydrogeologic assessment are to 1) Further characterize the extent of contamination, 2) identify possible remedial-action alternatives, and 3) evaluate the hydrogeologic effects of various remedial-action scenarios. This report includes information collected for objective two (phase I), which consists of hydrogeologic data compiled from April 1987 through April 1989. Purpose and Scope This report presents hydrogeologic data collected from April 1987 through April 1989 for Graces Quarters. The data include (1) the description of the observation-well networks, (2) lithologic data, and (3) hydrologic data. Twenty-six new observation wells were drilled and used in conjunction with five existing wells (one well, Q04, was never found) to establish a water-level and water-quality network. Lithologic data were collected from 5 test holes and 26 observation wells that were installed in 1988. These data include geophysical logs, lithologic descriptions of split-spoon and continuous core samples, and grain-size analyses from selected lithologic core samples. Data also are presented for slug tests that were performed to obtain an estimate of horizontal hydraulic conductivity at various locations in the Graces Quarters aquifers. Hydrologic data collected included monthly synoptic water levels measured in the wells with chalked steel tapes and continuous water-level data collected from analog to digital recorders (ADR's) that were installed on 11 wells. Data also were collected from a tide gage that was installed near Graces Quarters to help study groundwater and surface-...

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Chemical concentration and water temperature are given only in metric units. Chemical concentration in water is given in milligrams per liter (mg/L) or micrograms per liter (ug/L). Milligrams per liter is a unit expressing the solute per unit volume (liter) of water. One thousand micrograms per liter is equivalent to 1 milligram per liter. For concentrations less than 7,000 milligrams per liter, the numerical value is about the same as for concentrations in parts per million. Specific conductance is given in microsiemens per centimeter (uS/cm) at 25 C. Dissolved In this report, the term "dissolved" refers to constituents in a representative water sample that pass through a 0.45-micrometer membrane filter or a 0.7-micrometer glass fiber filter for organic analysis. Determinations of dissolved constituents are made on subsamples of the filtrate. Whole water, recoverable The term "total" used in this report means "whole water, recoverable," which refers to constituents in solution after a representative water-suspended-sediment sample is digested (usually using a dilute acid solution). Complete dissolution of paniculate matter often is not achieved by the digestion treatment, and thus the determination represents something less than the "total" amount (that is, less than 95 percent) of the constituent present in the dissolved and suspended phases of the sample. For inorganic determinations, digestions are performed in the original sample container to ensure digestion of material absorbed on the container walls. To achieve comparability of analytical data, equivalent digestion procedures would be required of all laboratories performing such analyses because different digestion procedures are likely to produce different analytical results. VERTICAL DATUM Sea level: In this report, "sea level" refers to the National Geodetic Vertical Datum of 1929 A geodetic datum derived from a general adjustment of the first-order level nets of the United States and Canada, formerly called "Sea Level Datum of 1929." Contents V

SUMMARYDuring 1993-95, water samples were collected at nine surfacewater sites in the Georgia-Florida Coastal Plain to determine nutrient concentrations. The sampling effort was part of the National Water Quality Assessment (NAWQA) Program by the U.S. Geological Survey.Nutrient concentrations in nine surface-water sites within the study area were relatively low compared to nationwide nutrient concentrations. The major dissolved nitrogen species in most of the surface-water sites was organic nitrogen. Among the data collected at these nine sites, the higher values could be attributed to agricultural and urban land use practices, degrading plant and animal material from forest and wetland areas, point-source discharges, or runoff from poultry and dairy farms.Nitrate concentrations in two of the nine rivers were highest when flows were lowest, indicating contributions from ground-water discharge to the rivers and influence from point-source discharges. At four sites nutrient concentrations increased during increases in discharge and decreased during decreases in discharge, suggesting a flush of nonpoint source contributions followed by dilution.

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