Groundwater flow was simulated for four areas in alluvial aquifers bordering the Ohio River in western West Virginia. The four groundwater flow models included well fields for the

The spatial and temporal distribution of recharge to carbonate and clastic aquifers along the eastern slopes of the Sandia Mountains was investigated by using precipitation, water-level, dissolved chloride, and specific-conductance data. The U.S. Geological Survey (USGS), in cooperation with the Bernalillo County Public Works Division, conducted a study to assess groundwater conditions and provide technical data that could be used as a basis for management and future planning of eastern Bernalillo County water resources. The intent of the investigation was to improve the current understanding of subsurface mechanisms controlling recharge dynamics in a geologically complex aquifer system. In the Sandia Mountains, precipitation events are generally limited to snowfalls in winter months and monsoon rainfall in late summer. Monthly meteorological data from weather stations in the study area indicate that monsoon rainfall during July and August constitutes close to one-third of annual precipitation totals. Following precipitation and snowmelt events, daily groundwater level data show low-amplitude, long-duration peaks in hydrographs of wells north and west of the Tijeras Fault. Hydrographs of monthly and biannual water-level data from across the study area show seasonal variation and water-level fluctuations in excess of 30 ft during a period of below-average precipitation. Water level observations in 67 percent of wells showing drought-induced water-level declines rebounded to at or near predrought conditions within 6 months of return to normal climate conditions. Cross-correlation of annual hydrologic data shows aquifer response to periods of monsoon recharge to persist from 1 to 6 months following events. The lag time between precipitation input and response of water levels or solute concentrations was largest near the Tijeras and Gutierrez Faults. These results indicate regional faults hydrologically isolate the Tijeras Graben from groundwater recharge originating at high elevations along the eastern slopes of the Sandia Mountains. Recharge rates calculated by using the chloride-mass-balance method for five springs located at the base of the Sandia Mountains ranged from 1 to 23 percent of annual precipitation. 1990). Using higher frequency sampling, Blanchard and Kues (1999) observed an apparent lag time of 1 month in 16 wells across the EMA following 7.4 inches of precipitation in July 1991. Groundwater age in the EMA was estimated by using chlorofluorocarbon (CFC) analyses to be 10-16 years in alluvial aquifers and 16-26 years in fractured rock aquifers (Blanchard, 2004).

Private and public wells throughout Morgan County, W. Va., were tested to determine aquifer hydraulic, geochemical, and water-quality characteristics. The entire study area is located in the Valley and Ridge Physiographic Province, a region of complex geologic structure and lithology. Aquifers in the study area are characterized by thin to thick bedded formations with interbedding among the various limestones, shales, sandstones, and siltstones that are folded into a series of steeply dipping north-south trending anticlines and synclines. Zones of groundwater production typically consist of one to two fracture sets, with little to no production from unfractured bedrock matrix. Measurements of transmissivity range from 2 to 1,490 feet squared per day, with the larger transmissivities occurring near bedding contacts and in zones with cross-faulting or jointing. Ground water flows from recharge areas in the uplands to local drainages and to deeper flow systems that appear to be controlled by regional geologic structure. The overall flow direction is from south to north within the study area. Ground water within the study area is predominantly a calcium-bicarbonate type water reflecting contact with carbonate rocks. Sodium-bicarbonate and calcium-magnesium-sulfate end-members also exist, with many samples exhibiting mixing, which may be the result of flow between the differing rock types or within units containing both carbonate rocks and shales. Values of water-quality characteristics that were greater than U.S. Environmental Protection Agency drinking-water standards included radon-222, pH, turbidity, iron, manganese, aluminum, and total-and fecal-coliform and Escherichia coli (E. coli) bacteria. Concentrations of radon-222 were detected in all samples from all units, with the largest concentrations (1,330 and 2,170 picocuries per liter) from the Clinton Formation.

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(ver. 1.1), online For more information on the USGS-the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1-888-ASK-USGS.For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprodTo order this and other USGS information products, visit http://store.usgs.gov Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner.Suggested citation: Masterson, J.P., Pope, J.P., Monti, Jack, Jr., Nardi, M.R., Finkelstein, J.S., and McCoy, K.J., 2015, Hydrogeology and hydrologic conditions of the Northern Atlantic Coastal Plain aquifer system from Long Island, New York, to North Carolina (ver. 1.1, September 2015): U.S. Geological Survey Scientific Investigations Report 2013-5133, 76 p., http://dx.doi.org/10.3133/sir20135133. ISSN 2328-031X (print) ISSN 2328-0328 (online) iii AcknowledgementsThe authors wish to thank the following individuals for their assistance and guidance throughout this investigation: Martha Watt, Jennifer Bonin, Fredrick Stumm, Jessica Carpenter, and Tom Reilly (emeritus) of the U.S. Geological Survey. The authors also would like to thank David Andreasen of the Maryland Geological Survey and Randy McFarland and Howard Reeves of the U.S. Geological Survey for providing technical reviews for this report. AbstractThe seaward-dipping sedimentary wedge that underlies