Bodies of rock that contain sufficient saturated permeable material to conduct ground water and to yield significant quantities of water to wells and springs. [Glossary of Geology, 4th ed.]
This program encompasses regional studies of ground water systems, multidisciplinary studies of critical ground water issues, access to ground-water data, and research and methods development.
Well vulnerability results from the young age of groundwater. Karst features permit contaminants to move into the aquifer easily, leading to a well mixed aquifer; geochemical processes do not degrade contaminants quickly.
Using ground-water geochemical analyses, and mathematical models, the factors affecting the quality of public water supply were identified as pumping schedule, screened interval, past land use within the recharge area, and natural geochemical conditions.
Using ground-water geochemical analyses and mathematical models, the factors affecting the quality of public water supply were identified as mixing of very recent recharge with older water, karst features, natural geochemical processes, and pumping.
Explains the natural and human-affected factors that determine the concentration of contaminants in groundwater, especially where the concentration is different at the surface than at depth, and where pumping varies with time.
Discussion and links to research for the multi-disciplinary investigation on the Norman Landfill located on alluvium associated with the Canadian River in central Oklahoma.
Description of the project to publish new bedrock geologic maps in the United States to advance the understanding of the region's bedrock aquifers. Includes list of projects.
Explains why we are assessing water quality in shallow aquifers, what we are measuring, and how the results will be reported both to well owners and to the public.
Summarizes graphically the areas where water levels have dropped, and by how much, in this extensive underground water reservoir that covers several states in the mid-continent.
Results of ground-surface monitoring and borehole water table measurements document subsidence of the land surface correlative with changes in the ground water.
This Nutrients National Synthesis Project site on the U.S. study of nutrients, especially nitrogen and phosphorus, as contaminants in high concentrations links to an overview, study team, featured reports, publications, and national datasets.
Knowledge of the geochemical processes controlling radium occurrence in groundwater may help water-resource managers anticipate and minimize human exposure to this cancer-causing element.
Summarizes measurements of ground-water chemistry that affect the vulnerability of aquifers to contamination. Data are from aquifers throughout the conterminous US and Alaska.
Study of the susceptibility and vulnerability of basin-fill aquifers in the region to ground-water contamination by synthesizing the information on ground-water quality conditions in 15 basins from previous studies.
Nitrate from fertilizer is degraded by microbial action in the presence of solid minerals. This helps mitigate the effect of the nitrate, but begins to diminish the solid minerals needed. Will the process be sustainable in the long term?
Information on aquifers in upstate New York which consist of unconsolidated deposits of sand and gravel that occupy major river and stream valleys or lake plains. Links to aquifer maps at scales 1:24,000 or 1:250,000 and cooperative publications.
Overview of a project in Virginia to develop a program for assessing public supply source waters to determine their susceptibility to contamination and to determine which systems need detailed source-water assessments.
Mathematical model of the groundwater system in this area includes 13 types of data and spans multiple aquifers over more than a century. This enables us to assess the quantity of groundwater, where and how it is being used, and how pumping affects it.
Complex report on the interpretation of aeromagnetic data to study hydrogeology of the San Pedro basin, Cochise County, Arizona determining geologic structure, basin fill and depth to water. Online version of a CD-ROM publication.
Recent increases in dissolved-solids concentrations in this aquifer have been documented in some areas used for public supply, raising concerns as to the sources and causes of the higher concentrations and the long-term effects on groundwater quality.
Detailed measurements of elevation help to understand the extent and severity of subsidence. Study asks if subsidence indicates the aquifer system is compacting temporarily or permanently, and are the changes human-induced or tectonic.
Water levels in wells completed in the Mississippi River Valley alluvial aquifer and the Sparta aquifer in eastern Arkansas respond to variability associated with annual precipitation.
Methods to depict the connectedness of rock units across fault and fracture zones, allowing us to determine the distribution of geologic units, structural features, and other controlling factors, such as porosity and permeability.
The U.S. ground water atlas consists of information on ground water resources of 13 regions covering the 50 States, Puerto Rico, and the U.S. Virgin Islands. Text and maps can be viewed online and downloaded as ASCII, GIF, and *.eps files.
Report examines what is known about the Nation's ground-water availability, and outlines a program of study to improve our understanding of ground-water availability in major aquifers across the Nation. With regional examples.
Links to Louisiana statewide aquifer and well information by locating parish on a map or selecting parish, aquifer, region, or type of ground-water data (real-time water levels or geophysical data) from lists.
Process and plan to be used to provide reliable evaluations of the potential effects of groundwater production and help guide sustainable management of the resource.
Five trace elements with human-health concerns were detected at high concentrations: arsenic, boron, fluoride, molybdenum, and strontium. Vanadium was present at moderate concentrations.
Trace elements were present at high concentrations in 32% of the primary aquifers here, and at moderate concentrations in 17%. Of particular interest are aluminum, arsenic, vanadium, boron, fluoride, chromium, lead, and molybdenum.
Recent study indicates that inorganic trace elements and radioactive constituents are more likely to be subjects of concern in this less-developed area than anthropogenic organic compounds.
The occurrence of solvents in the groundwater is not correlated with current overlying land use and human activities. Rather, the solvents are from legacy industrial uses, and it has taken decades for the groundwater to move to where it is now pumped.
Five trace elements with human-health concerns were detected at high concentrations: arsenic, boron, fluoride, molybdenum, and strontium. Chromium was detected at moderate concentrations.
Five trace elements with human-health concerns were detected at high concentrations: arsenic, boron, molybdenum, strontium, and vanadium. Chromium and fluoride were detected at moderate concentrations.
Arsenic was the trace element most frequently present at high concentrations here. High concentrations of arsenic result from the interaction of groundwater with naturally occurring minerals.
Uranium, arsenic, and nitrate were the inorganic constituents that were most frequently detected at high concentrations, mostly in shallower wells. High and moderate concentrations of arsenic were detected in deeper wells.
Six elements with human-health concerns were detected at high concentrations: arsenic, boron, fluoride, molybdenum, strontium, and vanadium. Lead was present at moderate concentrations.
This study of untreated groundwater indicates the number of samples in which inorganic or organic constituents occur in high or moderate in concentration. The study does not indicate significant problems in groundwater quality here.
Organic solvents are the chief concern in this area, which has given rise to a systematic program of monitoring and water treatment. This study shows relatively recent results.
The constituent present at high concentrations in the greatest proportion of the primary aquifer system was TDS, which is an indicator of salinity. Perchlorate was also present at moderate concentration in 42% of samples.
This study of untreated groundwater indicates the number of samples in which inorganic or organic constituents occur in high or moderate in concentration. The study does not indicate significant problems in groundwater quality here.
Arsenic and nitrate are the constituents found most commonly at high concentrations in the primary aquifers. Arsenic comes from natural sources and is affected by pH and dissolved oxygen.
Recent study indicating inorganic constituents as the primary items of concern in this area. Chemical and mineralogical compositions of the aquifer rocks probably explain variation among localities here.
Recent study encountered occasional high values of radioactive trace elements, but the water quality in this area as monitored compares favorably to more urban areas studied by the same group.
Recent study indicating nitrate and perchlorate are the primary inorganic constituents of interest here, coming from human activities such as agriculture.
Shallow groundwater has good quality, but salinity measured in wells suggests the thin lens of freshwater under the coastal plain will be vulnerable to saltwater intrusion as a consequence of pumping.
Lower precipitation and recharge, with deeper groundwater levels, suggest this basin will be less susceptible to contamination than others nearby, but may be susceptible to saltwater intrusion brought on by well pumping.
Describes and provides several detiled examples of impacts of human-induced land subsidence resulting from the extraction of subsurface water, including aquifer-system compaction, drainage of organic soils, dissolution and collapse of susceptible rocks.
Links to online data retrieval, information on MTBE and gasoline oxygenates, VOCs analysis, VOC publications, news features, and featured online publications.
Primary homepage for the National Water Quality Assessment (NAWQA) Program studying water quality in river, aquifer and coastal water basins throughout the nation. Links to reports, data, models, maps and national synthesis studies.
Links to New Jersey ground-water data including hydrogeology with a geologic map and description of major aquifers, water levels including real-time data and drought levels, and water-quality information.
How much water do you use to water your lawn, wash your car, or fill your swimming pool? Your answers to these questions have important implications for water supplies. A survey in this area showed the types of users and the ways in which water is used.
An assessment of pesticides in national water resources, with links to national reports, national statistics, national data, pesticide use, analytical strategy, and standards for the U.S.
Explains why phosphorus is important, how it moves through the terrestrial water system, how we measure it, and what this means for people who need to manage or monitor human activities that produce it.
Short descriptions of the research and monitoring activities we are carrying out to assist state, local, and Federal agencies dealing with water resource issues in the southern part of the state.
Software based on the MODFLOW modeling framework, used for studies of saltwater intrusion coastal aquifers, storage and recovery in brackish limestone aquifers, and brine migration in continental aquifers.
Research on contamination by trichloroethylene (TCE) in fractured rock at the Naval Air Warfare Center in Trenton, N.J. with links to site description, bibliography, online reports, and findings.
In 2005, about 29.2 million gallons per day (Mgal/d) of water were withdrawn here, including about 26.8 Mgal/d from groundwater sources and 2.45 Mgal/d from surface-water sources. Rice irrigation accounted for 74 percent (21.7 Mgal/d) of the total.
In 2005, about 30.6 million gallons per day (Mgal/d) of water was withdrawn here, including about 30.4 Mgal/d from groundwater and 0.1 Mgal/d from surface water. Industrial use, primarily for wood products, accounted for about 72 percent (22 Mgal/d).
In 2005, about 15.8 million gallons per day (Mgal/d) of water were withdrawn, including 4.12 Mgal/d from groundwater and about 11.7 Mgal/d from surface-water sources.Public supply use accounted for about 78 percent (12.4 Mgal/d) of the total water withdra
In 2005, about 72.9 million gallons per day (Mgal/d) of water were withdrawn here, including about 7.70 Mgal/d from groundwater sources and 65.2 Mgal/d from surface-water sources. Public-supply use accounted for about 71%, and power generation 19%.
Summarizes information on the water resources of Lafayette Parish, Louisiana. Information on groundwater and surface-water availability, quality, development, use, and trends is based on previously published reports.
In 2005, about 6.67 million gallons per day (Mgal/d) of water were withdrawn here, including about 6.46 Mgal/d from groundwater sources and 0.21 Mgal/d from surface-water sources. Public-supply use accounted for about 76 percent (5.06 Mgal/d) of the total
Description of project to study the distribution of saline water in the aquifers of the Coastal Plain of Virginia and the potential for saline water intrusion by evaluating chloride concentrations and the factors affecting chloride distribution.
In 2005, about 9.52 million gallons per day (Mgal/d) of water were withdrawn, including about 9.33 Mgal/d from groundwater and 0.19 Mgal/d from surface-water. Public supply use accounted for 70% of the total.