Publications

All groundwater pumped is balanced by removal of water somewhere, initially from storage in the aquifer and later from capture in the form of increase in recharge and decrease in discharge. Capture that results in a loss of water in streams, rivers, and wetlands now is a concern in many parts of the United States. Hydrologists commonly use analytical and numerical approaches to study...

The Potsdam Sandstone of Cambrian age forms a transboundary aquifer that extends across northern New York and into southern Quebec. The Potsdam Sandstone is a gently dipping sequence of arkose, subarkose, and orthoquartzite that unconformably overlies Precambrian metamorphic bedrock. The Potsdam irregularly grades upward over a thickness of 450 m from a heterogeneous feldspathic and...

Stream and reservoir stage are critical parameters in the computation of stream discharge and reservoir volume, respectively. In addition, a record of stream stage is useful in the design of structures that may be affected by stream elevation, as well as for the planning for various uses of flood plains. This report describes equipment and methodology for the observation, sensing, and...

During 2007-08 the U.S. Geological Survey, in cooperation with the U.S. Air Force, evaluated the concentration of polychlorinated biphenyls (PCBs) in aquatic invertebrates and fish from one site in the main body of Lake Worth, two sites in a small inlet in Lake Worth (upper and lower Woods Inlet), and one site in Meandering Road Creek in Fort Worth, Texas. The four sites sampled during...

Heavy rains in southern Georgia during March 27-April 3, 2009, and in northern Georgia during September 16-22, 2009, caused severe flooding and widespread damages to residential, public, and commercial structures. Of the 159 counties in Georgia, 69 were declared disaster areas because of flooding. The heavy rainfall in southern Georgia resulted in severe flooding in the Satilla-St. Marys...

Mercury is a global contaminant of concern due to its transformation by microorganisms to form methylmercury, a toxic species that accumulates in biological tissues. The effect of dissolved organic matter (DOM) isolated from natural waters on reactions between mercury(II) (Hg) and sulfide (S(-II)) to form HgS(s) nanoparticles across a range of Hg and S(-II) concentrations was...

Although the importance of vascular plant-derived dissolved organic carbon (DOC) in freshwater systems has been studied, the role of leached DOC as precursors of disinfection byproducts (DBPs) during drinking water treatment is not well known. Here we measured the propensity of leachates from four crops and four aquatic macrophytes to form trihalomethanes (THMs)—a regulated class of DBPs...

Ecological processes of low‐productivity ecosystems have long been considered to be driven by abiotic controls with biotic interactions playing an insignificant role. However, existing studies present conflicting evidence concerning the roles of these factors, in part due to the short temporal extent of most data sets and inability to test indirect effects of environmental variables...

Thirty-eight dated packrat middens were collected from upper desert (930–1357 m) elevations within Joshua Tree National Park near the ecotone between the Mojave Desert and Colorado Desert, providing a 30 ka record of vegetation change with remarkably even coverage for the last 15 ka. This record indicates that vegetation was relatively stable, which may reflect the lack of invasion by...

Drinking-water supplies from the Potomac-Raritan-Magothy aquifer system at the Puchack well field in Pennsauken Township, Camden County, New Jersey, have been contaminated by hexavalent chromium-the most toxic and mobile form-at concentrations exceeding the New Jersey maximum contaminant level of 100 micrograms per liter. Also, scattered but widespread instances of volatile organic...

The Umpqua River drains 12,103 km2 of western Oregon, heading in the Cascade Range and draining portions of the Klamath Mountains and Coast Range before entering the Pacific Ocean. Above the head of tide, the Umpqua River, along with its major tributaries, the North and South Umpqua Rivers, flows on a mixed bedrock and alluvium bed, alternating between bedrock rapids and intermittent...

Hydrographic characteristics of streamflow, such as high-flow pulses, base flow (background discharge between floods), extreme low flows, and floods, significantly influence aquatic organisms. Streamflow can be described in terms of magnitude, timing, duration, frequency, and variation (hydrologic regime). These characteristics have broad effects on ecosystem productivity, habitat...