Richard Yager

Biography

Richard Yager is a Research Hydrologist with the U.S. Geological Survey in Ithaca New York. He holds B.S. and M.S. degrees from Cornell University in Environmental Engineering (1973) and Agricultural Engineering (1980), respectively. He has been employed with the U.S. Geological Survey for 30 years, conducting hydrogeologic studies and developing simulation models of groundwater flow and transport.

 

Professional Experience
 
Groundwater flow in fractured sedimentary rock, Rockland Cty NY (2005 – 2009)
Groundwater from an inclined, fractured-rock aquifer supplies drinking water to over 300,000 people in Rockland County and there is concern that current withdrawal rates exceed recharge. A groundwater-flow model estimated the rate of recharge and age of groundwater, and delineated capture zones to well fields.
 
Migration of brine and saline water from a flooded salt mine, Genesee Cty NY (2005 – 2008)
The Retsof salt mine that flooded from 1994-1996 contains about 60 billion liters of saturated halite brine that is slowly displaced as the weight of overlying sediments causes the mine cavity to close. Saline water was detected in an overlying confined aquifer in 2002 and a brine-mitigation project was implemented in 2006 to prevent further migration of saline water. Geochemical and variable-density flow models were used to determine sources of salinity to the confined aquifer and to assess (1) processes that control movement and mixing of waters in the collapse area, (2) the effect of pumping on salinity, and (3) the potential for further land subsidence resulting from anhydrite dissolution.
 
Groundwater flow in folded, fractured sedimentary rock, Shenandoah Valley VA & WV (2004 – 2007)
Groundwater supplies drinking water to nearly 400,000 people in the Shenandoah Valley. Increasing development and periodic drought have led to concerns about the availability of ground water. A groundwater-flow model based on an innovative approach to represent the pattern of bedrock structure provided estimates of ground-water age and the depth of active flow.
 
Groundwater flow and brine migration in the Onondaga Trough, Syracuse NY (2002 – 2006)
Onondaga Lake has been identified as one of the Nation’s most polluted lakes and overlies a pool of halite brine in a glacial-drift aquifer.  The brine pool discharges to springs and obstructs the movement of ground water near the lake shore, thereby affecting the salinity of the lake and remedial efforts to improve lake-water quality. Geochemical and variable-density-flow models were used to simulate changes in the flow system resulting from anthropogenic development, and to estimate the age of the brine pool (16,000 years).
 
Effects of lake augmentation on leakage to the Floridan Aquifer, Hillsborough Cty FL (2000 – 2002)
Pumpage from the Upper Floridan aquifer has induced downward leakage from an overlying surficial aquifer and enhanced formation of sinkholes. This process is magnified beneath small lakes where the confining layer between the aquifers has been breached. Groundwater-flow models were developed to estimate leak­age rates beneath two lakes and to simulate the effects of augmenting lake stages.
 
Pumping effects on groundwater levels, salinity  and aquifer compaction, Hueco Basin TX (1997 – 2002)
Groundwater pumped from a trans-boundary aquifer supplies the cities of El Paso TX and Ciudad Juarez Chihuahua, Mexico. Increasing ground-water withdrawals during the past century has lowered water-level as much as 60 m. Ground-water flow and solute-transport models were developed simulated the effects of ground-water withdrawals from 1903 to 2002 and predicted changes in salinity in municipal well fields.
 
Estimating natural attenuation of chlorinated ethenes in fractured dolostone, Niagara Falls NY (1997 – 2002)
Tricholorethene (TCE) is a widespread contaminant in shallow aquifers and degradation by naturally occurring microorganisms is an important process that affects its fate in groundwater. These studies demonstrated the complete anaerobic degradation of TCE to ethene in a fractured-rock aquifer and estimated the degradation rates through solute-transport modeling.
 
Assessing the impact of mine flooding on a regional aquifer system, Livingston Cty NY (1995 – 1998)
Catastrophic roof collapses in one of the world’s largest salt mines resulted in flooding of the mine, causing water-level declines of over 120 m in overlying aquifers and land subsidence of 5 m above the collapse area. A groundwater-flow model estimated the extent of water-level declines, the time required for water levels to recover to pre-collapse conditions, and the impact of altered flow patterns on groundwater quality. Model results were also used to estimate the extent of land subsidence due to compac­tion of fine-grained glacial sediments, and to quantify the effect of gas exsolution caused by water-level decline on the specific storage of the aquifer.
 
Determination of contaminant source in a glacial-drift aquifer, Johnson City NY (1995 – 1997)
A glacial-drift aquifer that supplies water to Johnson City NY was contaminated by chlorinated hydrocarbons from an unknown source. A US Air Force manufacturing plant located near the municipal well field was scheduled for closure and suspected as the source. A groundwater-flow model delineated the contrib­uting area to the municipal well and was used to plan an off-site drilling program that subsequently identi­fied the contaminant source at another manufacturing plant.
 
Groundwater flow and river infiltration in a fractured dolostone aquifer, Niagara Falls (1987 – 1996)
More than 100 waste-disposal sites overly a fractured dolostone aquifer near Niagara Falls NY, including 21 USEPA priority sites. This multidisciplinary study utilized drilling, borehole and surface geophysics, hydraulic test­ing and geochemistry to characterize the aquifer system, and delineated regional, water-bearing fracture zones related to known stratigraphic horizons, thereby allowing the comparison of water-level and water-quality data from many different site investigations. A groundwater-flow model developed by the study has been used to to provide boundary conditions for several site-spe­cific models.
 
The extent of infiltration from the Niagara River to the aquifer was later delineated by comparing the isotopic content of ground water with water-level fluctuations induced by changes in river stage. The study delineated preferential flow paths of river infiltration through the aquifer to a nearby tunnel and determined that limiting the quantity of infiltration could substantially reduce the cost of treating the tunnel discharge. A project is currently underway to line the tunnel and limit the volume of river infiltration.
 
Hydrogeological studies near a former nuclear-fuels reprocessing plant, West Valley NY (1981 – 1993)
Tritium has been detected in groundwater near a former nuclear-fuels reprocessing plant at West Valley NY. A groundwater-flow model delineated the extent of contamination and estimated the rate of groundwater flow. A subsequent study examined state-of-the-art disposal technologies for the burial of low-level radioactive waste (LLRW) and proposed a field-scale experiment to investigate the effects LLRW burial on groundwater flow in glacial till near the plant. The study was never implemented as a result of political issues within New York State.
 
River infiltration to a shallow glacial-drift aquifer near Kirkwood NY (1983 – 1987)
Groundwater temperature was collected to delineate the extent of river-water infiltration induced by pumping from a nearby municipal well. A groundwater-flow model delineated the contributing area to the well and estimated the volume of river water discharged by the well. The model was later used to locate the migration path of tricholorethene (TCE) that reached the well from an adjacent landfill. Calibration of this model utilized nonlin­ear regression using a novel approach that approximated the sensitivity matrix through perturbation. This approach was later implemented in the USGS program UCODE.
 
Nitrogen transport through a shallow glacial-drift aquifer system near Olean NY (1984 – 1986)
Ammonia-nitrogen leaking from a former fertilizer plant contaminated groundwater in a glacial-drift aquifer. A solute-transport model predicted migration of nitrogen through the aquifer and was used in negotiations concerning shutdown of the fertilizer plant.
 
Stormwater runoff in an urban watershed, Rochester NY (1981 – 1983)
The study investigated sources, transport and accumulation patterns of storm-water contami­nants in the Irondequoit Basin in Monroe County. Rainfall-runoff models estimated contaminant loadings for different-sized basins from observed storm events.

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Articles in refereed journals

Yager, R.M., Voss, C.I., Southworth, Scott, 2009, Comparison of alternative representations of hydraulic-conductivity anisotropy in folded fractured-sedimentary rock: Modeling groundwater flow in the Shenandoah Valley (USA) , Hydrogeology Journal, v. 17, no. 5, p.1111-1131. http://www.springerlink.com/content/42527x186nr51794/fulltext.pdf

 

Yager, R.M., Kappel, W.M., and Plummer, L.N., 2007, Origin of halite brine in the Onondaga Trough near Syracuse, New York State, USA: modeling geochemistry and variable-density flow, Hydrogeology Journal, v. 15, no. 7, p. 1321-1339. http://www.springerlink.com/content/008m772313n73413/fulltext.pdf

 

Yager, R.M., 2004, Effects of model sensitivity and nonlinearity on nonlinear regression of ground water flow, Ground Water, v. 42, no. 3, p. 390-400.http://www3.interscience.wiley.com/cgi-bin/fulltext/118752546/PDFSTART

 

Yager, R.M., and Fountain, J. C., 2001, Effect of natural gas exsolution on specific storage in a confined aquifer undergoing water-level decline, Ground Water, v. 39, no. 4, p. 517-525.

http://www3.interscience.wiley.com/cgi-bin/fulltext/119017106/PDFSTART

Yager, R.M., 1998, Detecting influential observations in nonlinear regression modeling of ground- water flow, Water Resources Research, v. 34, no. 7, p. 1623-1633.

http://www.agu.org/journals/wr/v034/i007/98WR01010/

 

Yager, R.M., and Kappel, W. M., 1998, Infiltration and hydraulic connections from the Niagara River to a fractured dolomite aquifer in Niagara Falls, New York, Journal of Hydrol­ogy, v. 206, p. 84-97.

Yager, R.M., Bilotta, S. E., Mann, C. L., and Madsen, E. L., 1997b, Metabolic adaptation and in situ attenuation of chlorinated ethenes by naturally occurring microorganisms in a frac­tured dolomite aquifer near Niagara Falls, New York, Environmental Science and Technol­ogy, v. 31, no. 11, pp 3138-3147. http://pubs.acs.org/doi/pdf/10.1021/es970105a

 

Professional and Water Supply Papers

Yager, R.M., Misut, P.E., Langevin, C.D., and Parkhurst, D.L., 2009, Brine migration from a flooded salt mine in the Genesee Valley, Livingston County, New York: Geochemical modeling and simulation of variable-density flow, U. S. Geological Survey Professional Paper 1767, 51p. http://pubs.usgs.gov/pp/pp1767/

 

Yager, R.M., Miller, T. S., and Kappel, W. M., 2001, Simulated effects of salt-mine collapse on ground-water flow and land subsidence in a glacial aquifer system, Livingston County, N.Y., U. S. Geological Survey Professional Paper 1611, 85p. http://pubs.er.usgs.gov/usgspubs/pp/pp1611

 

Yager, R.M., 1996, Simulated three-dimensional ground-water flow in a fractured dolomite aquifer of the Lockport Group near Niagara Falls, New York: U. S. Geological Survey Water Supply Paper 2487, 42 p. http://pubs.er.usgs.gov/usgspubs/wsp/wsp2487

 

Yager, R.M., 1993, Estimation of hydraulic conductivity in a riverbed and aquifer system near the Susquehanna River, Broome County, New York: U. S. Geological Survey Water Supply Paper 2387, 49p. http://pubs.er.usgs.gov/usgspubs/wsp/wsp2387

Reports

Yager, R.M., Southworth, Scott, and Voss, C.I., 2009, Simulation of ground-water flow in the Shenandoah Valley, Virginia and West Virginia, using variable-direction anisotropy in hydraulic conductivity to represent bedrock structure, U. S. Geological Survey Scientific Investigations Report 2008-5002, 54p. http://pubs.usgs.gov/sir/2008/5002/

 

Kappel, W.M, and Yager, R.M., 2008, Ground-water-flow modeling of a freshwater and brine-filled aquifer in the Onondaga Trough, Onondaga County, New York—A summary of findings, U. S. Geological Survey Open-File Report 2007-1409, 12p. http://pubs.usgs.gov/of/2007/1409/

 

Yager, R.M., Kappel, W.M., and Plummer, L.N., 2007, Halite brine in the Onondaga Trough near Syracuse, New York: Characterization and simulation of variable-density flow, U. S. Geological Survey Scientific Investigations Report 2007-5058, 40p. http://pubs.usgs.gov/sir/2007/5058/

 

Yager, R.M., and Metz, P.A., 2004, Simulated effects of ground-water augmentation on the hydrology of Round and Halfmoon Lakes in northwestern Hillsborough Couty, Florida, U. S. Geological Survey Water-Resources Investigations Report 03-4322, 50p. http://pubs.er.usgs.gov/usgspubs/wri/wri034322

 

Heywood, C.E., and Yager, R.M., 2003, Simulated ground-water flow in the Hueco Bolson, an alluvial-basin aquifer system near El Paso, Texas, U. S. Geological Survey Water- Resources Investigations Report 02-4108, 73p. http://pubs.er.usgs.gov/usgspubs/wri/wri024108

 

Yager, R.M., 2001, Simulated transport and biodegradation of chlorinated ethenes in a frac­tured dolomite aquifer near Niagara Falls, N.Y., U. S. Geological Survey Water-Resources Investigations Report 00-4275, 56p. http://ny.water.usgs.gov/pubs/wri/wri004275/

 

Yager, R.M., Miller, T. S., and Thayer, John, 1997, Delineation of areas contributing recharge to municipal wells in three selected confined-glacial aqufiers in Erie County, New York: U. S. Geological Survey Water-Resources Investigations Report 96-4229, 40p. http://ny.water.usgs.gov/pubs/wri/wri964229

 

Coon, W.F., Yager, R.M., Surface, J.M., Randall, A.D., and Eckhardt, D.A., 1997, Hydroge­ology and water quality of the Clinton Street-Ballpark Aquifer near Johnson City, New York: U.S. Geological Survey Open-File Report 97-102, 57 p. http://ny.water.usgs.gov/pubs/of/of97102

 

Yager, R.M., 1996, Study plan for a field experiment to investigate the effects of low-level radioactive-waste burial on flow of water through a saturated, clayey till at West Valley, New York: U. S. Geological Survey Open-File Report 94-117, 40 p. http://pubs.er.usgs.gov/usgspubs/ofr/ofr94117

 

Yager, R.M., and Bergeron, M. P., 1988, Nitrogen transport in a shallow outwash aquifer at Olean, Cattaraugus County, New York: U. S. Geological Survey Water-Resources Investi­gations Report 87-4043, 51p. http://pubs.er.usgs.gov/usgspubs/wri/wri874043

 

Yager. R. M., 1987, Simulation of ground-water flow near the nuclear-fuels reprocessing facility at the Western New York Nuclear Service Center, Cattaraugus County, New York: U. S. Geological Survey Water-Resources Investigations Report 85-4308, 58p. http://pubs.er.usgs.gov/usgspubs/wri/wri854308

 

Bergeron, M. P., Kappel, W. M., and Yager, R.M., 1987, Geohydrologic conditions at the nuclear-fuels reprocessing plant and waste-management facilities at the Western New York Nuclear Service Center, Cattaraugus County, New York: U. S. Geological Survey Water- Resources Investigations Report 85-4145, 58p.http://pubs.er.usgs.gov/usgspubs/wri/wri854145

 

Yager. R. M., 1986, Simulation of ground-water flow and infiltration from the Susequehanna River to a shallow aquifer at Kirkwood and Conklin, Broome County, New York: U. S. Geological Survey Water-Resources Investigations Report 86-4123, 70p. http://pubs.er.usgs.gov/usgspubs/wri/wri864123

 

Kappel, W. M., Yager, R.M., and Zarriello, P. J., 1986, Quantity and quality of urban storm runoff in the Irondequoit Creek basin near Rochester, New York, Part 2. Quality of strom runoff and atmospheric deposition, rainfall-runoff-quality modeling and potential of wet­lands for sediment and nutrient retention: U. S. Geological Survey Water-Resources Investi­gations Report 85-4113, 170p. http://pubs.er.usgs.gov/usgspubs/wri/wri854113

 

Yager, R.M., Zarriello, P. J., and Kappel, W. M., 1985, Geohydrology of the Irondequoit Creek basin near Rochester, New York: U. S. Geological Survey Water-Resources Investi­gations Report 84-4259, 6 plates. http://pubs.er.usgs.gov/usgspubs/wri/wri844259

 

Published Proceedings

Yager, R.M. and Misut, P.E., 2008, Processes controlling migration of saline water and brine above a flooded salt mine: Insights from variable-density/viscosity modeling, Proceedings of the 20th Annual Salt Water Intrusion Meeting, June 2008, Naples FL, p. 321-324.

 

Yager, R.M., 2007, Comparison of alternative numerical models to represent permeability anisotropy in fractured-sedimentary rock, in Proceedings of the 2007 NGWA / USEPA Fractured-rock Conference, Portland ME, September 2007, p. 467-479.

 

Yager, R.M., 2003, Simulation of land subsidence in a glacial aquifer system above a salt- mine collapse redux: a post audit, in Prince, K.R. and Galloway, D.L., eds., U.S. Geological Survey Subsidence Interest Group Conference, Proceedings of the Technical Meeting, Galveston, Texas, November 27-29, 2001, U. S. Geological Survey Water-Resources Open- File Report 03-308, p. 71-80. http://pubs.er.usgs.gov/usgspubs/ofr/ofr03308

 

Yager, R.M., 2001, Estimating sedimentation rates in Cayuga Lake, New York from sedi­ment profiles of 137Cs and 210Pb activity, Eckhardt, D. A. V., and others (eds.), A sympo­sium on environmental research in the Cayuga Lake Watershed, Cornell University, N.Y., October 1999, Natural Resource, Agriculture and Engineering Science, Ithaca, N.Y., p. 78- 102.

 

Yager, R.M., 2000, Simulation of land subsidence in a glacial aquifer system above a salt mine collapse in New York USA, in Carbognin, L., Gambolati, G., and Johnson, A. I., (eds.), Land subsidence, Proceedings of the sixth international symposium on land subsid­ence, Ravenna, Italy, Sept. 2000, v. 2, p. 305-318.

 

Yager, R.M., 1995, Disposal of low-level radioactive waste below the water table: an exper­iment in clay-rich till at West Valley, New York, in Proceedings of Joint U. S. Geological Survey - U. S. Nuclear Regulatory Commission workshop on research related to low-level radioactive waste disposal, May 4-6, 1993, Reston, Va., P. R. Stevens and J. J. Nicholson, eds.: U. S. Geological Survey Water-Resources Investigations Report 95-4015, 211 p. http://pubs.er.usgs.gov/usgspubs/wri/wri954015

 

Yager, R.M., and Kappel, W. M., 1987, Detection and characterization of fractures and their relation to ground-water movement in the Lockport Dolomite, Niagara County, New York, in Pollution, Risk Assessment and Remediation in Groundwater Systems, R. M. Khanbilva­rdi and J. Fillos, eds.: Scientific Publications, New York, pp. 149-195.