Richard Yager (Former Employee)
Science and Products
Appalachian Plateau Groundwater Availablity Study
Pennsylvanian- and Mississippian-age aquifers occupy approximately 86,000 square-miles in the Appalachian Plateaus Physiographic Province of Pennsylvania, Ohio, Maryland, Virginia, West Virginia, Kentucky, Tennessee, and Alabama. As one of several USGS Regional Groundwater Studies, the primary goal of this study is to provide a regional understanding of groundwater flow and availability in the...
Hydrogeology and Simulation of Groundwater Flow in Fractured Rock in the Newark Basin, Rockland County, New York
Groundwater in the Newark basin aquifer flows primarily through discrete water-bearing zones parallel to the strike and dip of bedding, whereas flow perpendicular to the strike is restricted, thereby imparting anisotropy to the groundwater flow field. The finite-element model SUTRA was used to represent bedrock structure in the aquifer by spatially varying the orientation of the hydraulic...
Simulation of migration of brine and saline water from the flooded Retsof salt mine in the Genesee Valley, New York
Problem - Roof collapses in the Retsof salt mine near Geneseo N.Y. in March and April of 1994 propagated upward through overlying bedrock, forming a 600-ft-long rubble zone or chimney that connected the mine to a glacial aquifer system and created sinkholes at land surface. Fresh water from the glacial aquifers flowed downward into the mine until the mine was completely flooded in January 1...
Ground-water-flow model of the Shenandoah Valley, Virginia and West Virginia
Problem - Increasing development within the Shenandoah Valley in recent years has placed additional demands on the region’s water resources. The sedimentary rocks in the Valley have been compressed and folded by tectonic forces to form a 5-km deep basin. Ground water, a principal component of the available water supply, flows through fractures in the sedimentary and crystalline rocks that un...
Variable-density groundwater flow and contaminant transport, Operable Unit 1, Naval Base Kitsap, Keyport, Washington
Chlorinated volatile organic compounds (CVOCs) have migrated to groundwater beneath a former 9-acre landfill at Operable Unit 1 (OU-1) on Naval Base Kitsap, which was active from the 1930s through 1973 on the Keyport Peninsula, in Kitsap County, Washington. Biodegradation of CVOCs at OU-1 limits the mass of dissolved-phase CVOCs in groundwater...
Yager, Richard M.; Welch, Wendy B.; Headman, Alexander; Dinicola, Richard S.
Drinking water quality in the glacial aquifer system, northern USA
Groundwater supplies 50% of drinking water worldwide, but compromised water quality from anthropogenic and geogenic contaminants can limit usage of groundwater as a drinking water source. Groundwater quality in the glacial aquifer system, USA (GLAC), is presented in the context of a hydrogeologic framework that divides the study area into 17...
Erickson, Melinda L.; Yager, Richard M.; Kauffman, Leon J.; Wilson, John T.
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)...
Yager, Richard M.; Kauffman, Leon J.; Soller, David R.; Haj, Adel E.; Heisig, Paul M.; Buchwald, Cheryl A.; Westenbroek, Stephen, M.; Reddy, James E.
Hydrogeologic framework for characterization and occurrence of confined and unconfined aquifers in quaternary sediments in the glaciated conterminous United States—A digital map compilation and database
The U.S. Geological Survey has created a hydrogeologic framework for Quaternary sediments in glaciated areas of the conterminous United States that categorizes, maps, and characterizes the glacial sediments at and beneath the land surface. The hydrogeologic framework divides the glaciated United States into 17 distinct hydrogeologic terranes using...
Haj, Adel E.; Soller, David R.; Reddy, James E.; Kauffman, Leon J.; Yager, Richard M.; Buchwald, Cheryl A. The role of uplift and erosion in the persistence of saline groundwater in the shallow subsurface
In many regions of the world, the shallow (<300 m) subsurface is replenished with meteoric recharge within a few centuries or millennia, but in some regions saline groundwater persists despite abundant rainfall. Analyses of the flushing rate of shallow groundwater usually consider the permeability and recharge rate and a static landscape....
Yager, Richard M.; McCoy, Kurt J.; Voss, Clifford I.; Sanford, Ward E.; Winston, Richard B. Interpretation of hydraulic conductivity in a fractured-rock aquifer over increasingly larger length dimensions
A comparison of the hydraulic conductivity over increasingly larger volumes of crystalline rock was conducted in the Piedmont physiographic region near Bethesda, Maryland, USA. Fluid-injection tests were conducted on intervals of boreholes isolating closely spaced fractures. Single-hole tests were conducted by pumping in open boreholes for...
Shapiro, Allen M.; Ladderud, Jeffery; Yager, Richard M.
Hydrogeology and simulation of groundwater flow in fractured-rock aquifers of the Piedmont and Blue Ridge Physiographic Provinces, Bedford County, Virginia
An annual groundwater budget was computed as part of a hydrogeologic characterization and monitoring effort of fractured-rock aquifers in Bedford County, Virginia, a growing 764-square-mile (mi2) rural area between the cities of Roanoke and Lynchburg, Virginia. Data collection in Bedford County began in the 1930s when continuous stream gages were...
McCoy, Kurt J.; White, Bradley A.; Yager, Richard M.; Harlow, George E.
Hydrologic budget and conditions of Permian, Pennsylvanian, and Mississippian aquifers in the Appalachian Plateaus physiographic province
In response to challenges to groundwater availability posed by historic land-use practices, expanding development of hydrocarbon resources, and drought, the U.S. Geological Survey Groundwater Resources Program began a regional assessment of the Appalachian Plateaus aquifers in 2013 that incorporated a hydrologic landscape approach to estimate all...
McCoy, Kurt J.; Yager, Richard M.; Nelms, David L.; Ladd, David E.; Monti,, Jack; Kozar, Mark D. Simulation of the effects of seasonally varying pumping on intraborehole flow and the vulnerability of public-supply wells to contamination
Public-supply wells with long screens in alluvial aquifers can produce waters of differing quality from different depths. Seasonal changes in quality are linked to seasonal changes in pumping rates that influence the distribution of flow into the well screens under pumping conditions and the magnitude and direction of intraborehole flow within the...
Yager, Richard M.; Heywood, Charles E.
Environmental consequences of the Retsof Salt Mine roof collapse
In 1994, the largest salt mine in North America, which had been in operation for more than 100 years, catastrophically flooded when the mine ceiling collapsed. In addition to causing the loss of the mine and the mineral resources it provided, this event formed sinkholes, caused widespread subsidence to land, caused structures to crack and subside...
Yager, Richard M. Comparison of age distributions estimated from environmental tracers by using binary-dilution and numerical models of fractured and folded karst: Shenandoah Valley of Virginia and West Virginia, USA
Measured concentrations of environmental tracers in spring discharge from a karst aquifer in the Shenandoah Valley, USA, were used to refine a numerical groundwater flow model. The karst aquifer is folded and faulted carbonate bedrock dominated by diffuse flow along fractures. The numerical model represented bedrock structure and discrete features...
Yager, Richard M.; Plummer, Niel; Kauffman, Leon J.; Doctor, Daniel H.; Nelms, David L.; Schlosser, Peter
Assessing potential effects of changes in water use with a numerical groundwater-flow model of Carson Valley, Douglas County, Nevada, and Alpine County, California
Rapid growth and development within Carson Valley in Douglas County, Nevada, and Alpine County, California, has caused concern over the continued availability of groundwater, and whether the increased municipal demand could either impact the availability of water or result in decreased flow in the Carson River. Annual pumpage of groundwater has...
Yager, Richard M.; Maurer, Douglas K.; Mayers, C.J.