Science Explorer
Exploring: Groundwater
The dual‐domain porosity apparatus: Characterizing dual porosity at the sediment/water interface
The characterization of pore-space connectivity in porous media at the sediment/water interface is critical to understanding contaminant transport and reactive biogeochemical processes in zones of groundwater and surface-water exchange. Previous in situ studies of dual-domain (i.e., mobile/less-mobile porosity) studies have been limited to...
The Mississippi Alluvial Plain aquifers—An engine for economic activity
U.S. Geological Survey science supports groundwater resource management in the Mississippi Alluvial Plain region. The USGS Science and Decisions Center is working with the Water Availability and Use Science Program to integrate economics into a sophisticated model of groundwater in the region. The model will quantify the status of the groundwater...
Monitoring the pulse of our Nation's rivers and streams—The U.S. Geological Survey streamgaging network
In the late 1800s, John Wesley Powell, second Director of the U.S. Geological Survey (USGS), proposed gaging the flow of rivers and streams in the Western United States to evaluate the potential for irrigation. Around the same time, several cities in the Eastern United States established primitive streamgages to help design water-supply systems....
Elevated manganese concentrations in United States groundwater, role of land surface–soil–aquifer connections
Chemical data from 43 334 wells were used to examine the role of land surface–soil–aquifer connections in producing elevated manganese concentrations (>300 μg/L) in United States (U.S.) groundwater. Elevated concentrations of manganese and dissolved organic carbon (DOC) in groundwater are associated with shallow, anoxic water tables and soils...
Hydrogeologic controls and geochemical indicators of groundwater movement in the Niles Cone and southern East Bay Plain groundwater subbasins, Alameda County, California
Beginning in the 1970s, Alameda County Water District began infiltrating imported water through ponds in repurposed gravel quarries at the Quarry Lakes Regional Park, in the Niles Cone groundwater subbasin, to recharge groundwater and to minimize intrusion of saline, San Francisco Bay water into freshwater aquifers. Hydraulic connection between...
Identifying natural and anthropogenic variability of uranium at the well scale, Homestake Superfund site, near Milan, New Mexico, USA
The San Mateo Creek Basin in New Mexico, USA is located within the Grants Mineral Belt-an area with numerous uranium (U) ore deposits, mines, and milling operations. Six monitoring wells set in an alluvial aquifer near the Homestake Mining Co. Superfund site in the lower San Mateo Creek Basin were logged with a suite of borehole geophysical tools...
Development of perennial thaw zones in boreal hillslopes enhances potential mobilization of permafrost carbon
Permafrost thaw alters subsurface flow in boreal regions that in turn influences the magnitude, seasonality, and chemical composition of streamflow. Prediction of these changes is challenged by incomplete knowledge of timing, flowpath depth, and amount of groundwater discharge to streams in response to thaw. One important phenomenon that may...
Characterization and occurrence of confined and unconfined aquifers in Quaternary sediments in the glaciated conterminous United States
The glacial aquifer system, which is a collection of aquifers within Quaternary sediments in the glaciated conterminous United States, is a principal aquifer that supplies groundwater that serves about 42 million people and accounts for about 5 percent of the Nation’s drinking water. This aquifer system (the area of maximum glacial advance)...
Delineation of selected lithologic units using airborne electromagnetic data near Cedar Rapids, Iowa
The U.S. Geological Survey, in cooperation with the City of Cedar Rapids, began a study in 2013 to better understand the effects of drought stress on the Cedar River alluvial aquifer. After an evaluation of the existing groundwater-flow models for the alluvial aquifer, a plan was begun to construct an updated groundwater-flow model capable of...
Seasonality of nitrate sources and isotopic composition in the Upper Illinois River
To improve understanding of spatial, seasonal, and inter-annual variations in nitrate sources and in-stream processes in the Illinois River system, nitrate concentrations and isotopic compositions were measured in 445 water samples collected over a four-year period (2004–2008) from the Upper Illinois River Basin (UIRB). Samples included surface...
Chapter A6.3. Specific Conductance
The “National Field Manual for the Collection of Water-Quality Data” (NFM) provides guidelines and procedures for U.S. Geological Survey (USGS) personnel who collect data used to assess the quality of the Nation’s surface-water and groundwater resources. This chapter, NFM A6.3, provides guidance and protocols for the measurement of specific...
Potential for increased inundation in flood-prone regions of southeast Florida in response to climate and sea-level changes in Broward County, Florida, 2060–69
The U.S. Geological Survey, in cooperation with Broward County Environmental Planning and Resilience Division, has developed county-scale and local-scale groundwater/surface-water models to study the potential for increased inundation and flooding in eastern Broward County that are due to changes in future climate and sea-level rise. These models...
Factors affecting the occurrence of lead and manganese in untreated drinking water from Atlantic and Gulf Coastal Plain aquifers, eastern United States—Dissolved oxygen and pH framework for evaluating risk of elevated concentrations
Groundwater samples collected during 2012 and 2013 from public-supply wells screened in the Atlantic and Gulf Coastal Plain aquifers of the eastern and southeastern U.S. rarely contained lead or manganese concentrations that exceeded drinking-water limits, despite having corrosive characteristics. Data indicate that the...
Linking landscapes and people—Projecting the future of the Great Plains
We developed a unique set of landscape projections for the Great Plains that use real land-management parcels to represent landscape patterns at high spatial and thematic resolution.Both anthropogenic land use and natural vegetation respond in the model to projected changes in groundwater availability and climate...
Hydrogeology of Lower Amargosa Valley and groundwater discharge to the Amargosa Wild and Scenic River, Inyo and San Bernardino Counties, California, and adjacent areas in Nye and Clark Counties, Nevada
In 2009, Congress designated certain reaches of the Amargosa River in Inyo County, California between the town of Shoshone and Dumont Dunes as a Wild and Scenic River. As part of the management of the Amargosa Wild and Scenic River, the Bureau of Land Management cooperated with the U.S. Geological Survey to assess the surface and groundwater...
Preferential groundwater seepage in karst terrane inferred from geoelectric measurements
The Ellenburger–San Saba aquifer discharges spring flows into the overlying Hamilton Creek bed in Burnet County, central Texas. The aquifer is susceptible to contamination from surface‐water reservoirs because of the presence of dissolution cavities that are hydraulically connected to the reservoirs in some locations. There is concern that...
Mini-columns and ghost columns in Columbia river lava
The master joints bounding the columns that make up the basal colonnade of large lava flows of the Columbia Plateau are, in places, flanked by sub-horizontal mini-columns that have grown normal to the master joints. The secondary mini-columns grow into the main columns and are clearly younger than them. They are small adjacent to the master joint...
Linkages between hydrology and seasonal variations of nutrients and periphyton in a large oligotrophic subalpine lake
Periphyton is important to lake ecosystems, contributing to primary production, nutrient cycling, and benthic metabolism. Increases in periphyton growth in lakes can be indicative of changes in water quality, shifts in ecosystem structure, and increases in nutrient fluxes. In oligotrophic lakes, conservationists are interested in characterizing...
Efficient hydrogeological characterization of remote stream corridors using drones
This project demonstrates the successful use of small unoccupied aircraft system (sUASs) for hydrogeological characterization of a remote stream reach in a rugged mountain terrain. Thermal infrared, visual imagery, and derived digital surface models are used to inform conceptual models of groundwater/surface‐water exchange and efficiently...