Publications

The purpose of the Reston Stable Isotope Laboratory (RSIL) lab code 2900 is to determine the δ15N and δ18O of nitrate (NO3-) in water. The δ15N and δ18O of the dissolved NO3- are analyzed by converting the NO3- to nitrous oxide (N2O), which serves as the analyte for mass spectrometry. A culture of denitrifying bacteria is used in the enzymatic conversion of the NO3- to N2O, which follows...

The purpose of the Reston Stable Isotope Laboratory (RSIL) lab code 2897 is to determine the δ15N and δ18O of nitrate (NO3-) in solids. The NO3- fraction of the nitrogen species is dissolved by water (called leaching) and can be analyzed by the bacterial method covered in RSIL lab code 2900. After leaching, the δ15N and δ18O of the dissolved NO3- is analyzed by conversion of the NO3- to...

Each summer the population of the barrier-island communities of New Jersey increases by tens of thousands. When a coastal storm threatens these communities, the limited number of bridges and causeways that connect the islands with the mainland become overcrowded, making evacuations from the barrier islands to the mainland difficult. Timely evacuation depends on well-defined emergency...

More than 800 wells in the glacial aquifer system of the Northern United States were sampled for arsenic as part of U.S. Geological Survey National Water-Quality Assessment (NAWQA) studies during 1991-2003. Elevated arsenic concentrations (greater than or equal to 10 micrograms per liter) were detected in 9 percent of samples. Elevated arsenic concentrations were associated with strongly...

A graphical method that uses continuous water-level and barometric-pressure data was developed to estimate barometric efficiency. A plot of nearly continuous water level (on the y-axis), as a function of nearly continuous barometric pressure (on the x-axis), will plot as a line curved into a series of connected elliptical loops. Each loop represents a barometric-pressure fluctuation. The...

During times of drought, ground water in the Lodgepole Creek area around Sidney, western Nebraska, may be insufficient to yield adequate supplies to private and municipal wells. Alternate sources of water exist in the Cheyenne Tablelands north of the city, but these sources are limited in extent. In 2003, the U.S. Geological Survey and the South Platte Natural Resources District began a

The peak discharge record at the U.S. Geological Survey (USGS) gaging station at Skagit River near Concrete, Washington, is a key record that has come under intense scrutiny by the scientific and lay person communities in the last 4 years. A peak discharge of 240,000 cubic feet per second for the flood on December 13, 1921, was determined in 1923 by USGS hydrologist James Stewart by...

Potential flow characteristics of future flooding along a 4.8-mile reach of the Flint River in Albany, Georgia, were simulated using recent digital-elevation-model data and the U.S. Geological Survey finite-element surface-water modeling system for two-dimensional flow in the horizontal plane (FESWMS-2DH). Simulated inundated areas, in 1-foot (ft) increments, were created for water...

The U.S. Geological Survey, in cooperation with the City of Seward, Nebraska, conducted a study of ground-water age and quality to improve understanding of: (1) traveltimes from recharge areas to public-supply wells, (2) the effects of geochemical reactions in the aquifer on water quality, and (3) how water quality has changed historically in response to land-use practices. Samples were...

Ground-water temperature data were collected by the U.S. Geological Survey in wells at and in the vicinity of the Nevada Test Site during the years 2000-2006. Periodic ground-water temperatures were collected in 166 wells. In general, periodic ground-water temperatures were measured annually in each well at 5 and 55 feet below the water surface. Ground-water temperature profiles were...

Ground water moving through permeable Paleozoic carbonate rocks represents the most likely pathway for migration of radioactive contaminants from nuclear weapons testing at the Nevada Test Site, Nye County, Nevada. The strontium isotopic composition (87Sr/86Sr) of ground water offers a useful means of testing hydrochemical models of regional flow involving advection and reaction. However...

The Natural Resources Conservation Service (NRCS) is proposing to build a dry dam on the South Fork Licking River to mitigate flood impacts. Concerns have been raised regarding the effects of impounded floodwaters on ground-water conditions in the Swamp Road neighborhood. To obtain a better understanding of existing ground-water conditions, the U.S. Geological Survey, in cooperation with...