Ph.D. University of Wisconsin
Office: SB E-212
Telephone: (718) 997-3327
FAX: (718) 997-3299

Research Interests

My research interests are in the areas of groundwater and surface water hydrology, and in the use of shallow subsurface geophysics to characterize shallow aquifer systems in urban settings.

Groundwater and surface water systems in urban areas are often highly transformed by urbanization. Changes in land use affect runoff and infiltration processes, and changes in municipal water supply sources cause aquifer drawdown and recovery. Baseflow in streams that has been reduced by long-term groundwater pumping can recover as the water table rebounds. This is the case in the largely urbanized area in Queens.

Water quality in urban estuaries depends on the amounts and quality of surface water and groundwater discharge into them. In Flushing Bay, adjacent to LaGuardia Airport on the north shore of Queens, water quality has been severely degraded by many decades of discharges from combined sewer overflows (CSO). However, major improvements are currently being made in the stormwater infrastructure to retain and treat these CSO discharges in Flushing Bay. At the same time, groundwater discharge is projected to increase from the rebounding water table, since current municipal supply is no longer from the aquifer but primarily from the upstate reservoir and aqueduct system. With several graduate students, I am currently studying salinity and water quality changes in Flushing Bay as a result of these changes in discharge.

Mixing processes are important in estuaries, where freshwater from groundwater or surface water mixes with saline water from the marine environment. With the tidal fluctuation, salinity and hydraulic head change over time, interacting in complex ways with freshwater discharge. One way to investigate these processes is using numerical groundwater flow models, including models that account for density differences. Analytical solutions to the one dimensional hydraulic equations for salinity intrusion have been developed for alluvial estuaries. I am using these solutions to constrain freshwater discharge and longitudinal dispersion coefficient for Flushing Bay.

My interest in geological heterogeneity and how it affects groundwater flow, previously applied to bedrock aquitards in Wisconsin, has now shifted to shallow aquifers in urbanized environments. Up to 20% of the land surface in NYC is composed of artificial fill that has replaced tidal wetlands. Groundwater discharges through these materials, about which little is known. Subsurface geophysical methods, such as ground penetrating radar (GPR) and earth resistivity, can be used to image these sediments. I am interested in using these technologies to distinguish different types of materials, natural and anthropogenic, and understand their impact on groundwater quality.

Teaching Philosophy and Interests

My teaching interests are surface and groundwater hydrology, shallow subsurface geophysics, and field methods in environmental sciences.

A list of classes taught:

Undergraduate Classes

• GEOL347 Introductory Hydrology
• GEOL383 Groundwater Hydrology

Graduate Classes

• GEOL 744 Groundwater Flow Modeling
• GEOL 745 Hydrology
• GEOL 746 Groundwater Hydrology
• GEOL 761 Field Methods in Hydrology
• GEOL 762 Shallow Subsurface Geophysics
• GEOL 767 Field Techniques in Environmental Geoscience

Selected Publications

Eaton, T.T. in preparation. Analytical estimates of hydraulic parameters for an urbanized estuary – Flushing Bay. Journal of Hydrology

Eaton, T.T., M.P. Anderson, and K.R. Bradbury. 2007. Fracture control of ground water flow and water chemistry in a rock aquitard. Ground Water in press

Eaton, T.T. 2006. Hydrogeology – principles and practice. Invited book review. Ground Water 44(3): 326. doi: 10.1111/j.1745-6584.2006.00214.x

Eaton, T.T. 2006. On the importance of geological heterogeneity for flow simulation. Sedimentary Geology 184(3-4): 187-201

Eaton, T.T. 2006. Heterogeneity in sedimentary aquifers: challenges for characterization and for flow modeling. Sedimentary Geology 184(3-4): 183-186

Eaton, T.T. and K.R. Bradbury. 2003. Hydraulic transience and the role of bedding fractures in a bedrock aquitard, southeastern Wisconsin, USA, Geophysical Research Letters 30(18). doi:10.1029/2003GL017913