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This report contains hydrologic and climatic data that describe the status of ground-water resources at U.S. Navy Support Facility, Diego Garcia. Data presented are from January 1993 through December 1995, although the report focuses on hydrologic events from October through December 1995 (fourth quarter of 1995). Cumulative rainfall for October...

Water-level data for 171 wells and one surface-water site on Red Lion Creek in the industrial area northwest of Delaware City, Delaware, are presented for 1993 and 1994. Eight sets of synoptic ground- water-level measurements collected between April 1993 and September 1994, and locations and field notes for the 171...

The hydrogeologic framework of the Valley and Ridge Physiographic Province in Maryland, New Jersey, and Pennsylvania was analyzed by the U.S. Geological Survey as part of the Appalachian Valleys— Piedmont Regional Aquifer-System Analysis project. Local differences in lithology, structure, and weathering result in large variation in the water-yielding properties of...

In inland areas of northwest central Florida, sulfate concentrations in the Upper Floridan aquifer are extremely variable and sometimes exceed drinking water standards (250 milligrams per liter). This is unusual because the aquifer is unconfined and near the surface, allowing for active recharge. The sources of sulfate and geochemical processes...

The Regional Aquifer-System Analysis (RASA) program is a series of studies by the U.S. Geological Survey (USGS) to analyze regional ground-water systems that compose a major portion of the Nations water supply (Sun, 1986). The Northern Rocky Mountains Intermontane Basins is one of the study regions in this national program....

No abstract available....

In 1992, the U.S. Army Corps of Engineers and the U.S. Army Pueblo Depot Activity requested that the U.S. Geological Survey study the hydrogeology of the Pueblo Depot Activity, a 36-square-mile facility that has been operated by the U.S. Army since 1942. The purpose of the study was to provide...

The South Platte River Basin was one of 20 river basins selected in 1991 for investigation as part of the U.S. Geological Survey's National Water- Quality Assessment (NAWQA) Program. Nationwide, nutrients have been identified as one of the primary nationwide water-quality concerns and are of particular interest in the...

During the early phase of the Georgia-Florida National Water Quality Assessment study, existing information on nutrients was compiled and analyzed in order to evaluate the nutrient concentrations within the 61,545 square mile study unit. Evaluation of the nutrient concentrations collected at surface- water sites between October 1, 1970, and September...

Urban areas in Perris Valley, California, have more than tripled during the last 20 years. To quantify the effects of increased urbanization on storm runoff volumes and peak discharges, rainfall-runoff models of the basin were developed to simulate runoff for 1970-75 and 1990-93 conditions. Hourly rainfall data for 1949-93 were...

Natural monthly streamflows were synthesized for the years 1928-89 for 43 sites in the upper Missouri River Basin upstream from Fort Peck Lake in Montana. The sites are represented as nodes in a streamflow accounting model being developed by the Bureau of Reclamation. Recorded and historical flows at most sites...

The City of Columbus, Ohio, operates four radial collector wells in southern Franklin County. The 'South Well Field' is completed in permeable outwash and ice-contact deposits, upon which flow the Scioto River and Big Walnut Creek. The wells are designed to yield approximately 42 million gallons per day; part of...

Laboratory and quality assurance procedures for the analysis of ground-water samples for herbicides at the Management Systems Evaluation Area near Princeton, Minnesota are described. The target herbicides include atrazine, de-ethylatrazine, de-isopropylatrazine, metribuzin, alachlor, 2,6-diethylaniline, and metolachlor. The analytical techniques used are solid-phase extraction, and analysis by gas chromatography with mass-selective...

The Mojave River and the associated floodplain aquifer are important water supplies in the Mojave Desert of Southern California. The river and aquifer, in many areas, are in excellent hydraulic connection, and when flow conditions change in one, the other almost always is affected.To better understand these relations, records of...

The alluvial aquifer at Louisville, Ky., lies in a valley eroded by glacial meltwater that was later partly filled with outwash sand and gravel deposits. The aquifer is primarily unconfined, and the direction of flow is from the adjacent limestone and shale valley wall toward the Ohio River and major...

Ground-water resources of the Blackfeet Indian Reservation are facing increased development for domestic and public drinking-water supplies and for industrial use. Along with the increased demand for ground-water data to address water-rights issues, water-quality concerns, and water-management decisions. The increased demand for ground water and ground-water data highlighted the need...

Upper Klamath Lake is a large (140 square-mile), shallow (mean depth about 8 ft) lake in south-central Oregon that the historical record indicates has been eutrophic since its discovery by non-Native Americans. In recent decades, however, the lake has had annual occurrences of near- monoculture blooms of the blue-green alga...

Greater-than-normal precipitation during the summer of 1993 affected the hydrologic response and surface-water quality in the Devils Lake Basin. Large areas in the basin were flooded as a result of the precipitation, and water from these areas drained slowly through the chain of lakes into Devils Lake. This report summarizes...

Inductively coupled plasma-atomic emission spectrometry is a sensitive, rapid, and accurate method for determining the dissolved concentration of aluminum and boron in water samples. The method detection limits are 5 micrograms per liter for aluminum and 4 micrograms per liter for boron. For aluminum, low-level (about 30 micrograms per liter)...

The Anadarko basin is a large, deep, two-stage Paleozoic basin (Feinstein, 1981) that is petroleum rich and generally well explored. The Anadarko basin province, a geogrphic area used here mostly for the convenience of mapping and data management, is defined by political boundaries that include the Anadarko basin proper. The...

Flood-plain and channel-aggradation rates were estimated at 10 bridge sites on the Iowa River upstream of Coralville Lake and at two bridge sites in the central part of the Skunk River Basin. Four measurement methods were used to quantify aggradation rates: (1) a dendrogeomorphic method that used tree-age data and...