The Hydrogeology Group examines the quality and quantity of water resources in the world today with emphasis on solving the environmental problems caused by ever-increasing human stress on hydrolic systems.

Dr. Tim Grundl, Professor

Timothy Grundl

Tim Grundl

Specializing in groundwater contamination, contaminant fate and transport, and regional scale aquifer dynamics.

Research: I am currently involved in multiple lines of inquiry. The first is a comprehensive look into the overall geochemistry of the deep sandstone aquifer in eastern Wisconsin and the upper Midwest in general. This aquifer is the pre-eminent source of groundwater within Wisconsin and Illinois. The resource is being over utilized and is coming under increasingly severe stress. The last of the Pleistocene ice advances injected a large pulse of fresh Pleistocene water into this aquifer. Glacial-groundwater interplay is of great interest to glaciologists and hydrologists alike and has water supply implications as this water is “mined” for drinking water.

Another aspect of this work is a study of the shallow aquifer in southeastern Wisconsin to ascertain what effects would occur if treated effluent, complete with a high chloride load and a variety of emerging contaminants is used to recharge the aquifer. We are currently exploring several geochemical indicators to discriminate between recharge that contains treated effluent and recharge impacted by road salt.

A third line of inquiry is the development, in collaboration with other colleagues, of a suite of in-situ probes for the rapid, screening level detection of contamination in harbor sediments. Sediment borne contamination is the major source of contaminants to the surface waters of the United States. Remediation efforts would be much more focused and inexpensive if a better means to initially characterize the extent of contamination was employed. Current techniques depend on expensive networks of discrete sampling sites that can be 100s to 1000s of meters apart. Our probes allow real-time identification of PAH and heavy metal contamination in harbor sediments for a fraction of the effort involved in the typical coring and subsequent lab analysis that is in use today.

Dr. Weon Shik Han, Associate Professor

Weon Han

Weon Shik Han

Specializing in non-isothermal multiphase and reactive transport modeling in heterogeneous porous media with emphasis of geologic C02 sequestration and groundwater hydrology.

Research: My research focuses on environmental, climate change, and energy related research such as geologic CO2 sequestration, groundwater hydrology, and geothermal energy development with an emphasis in multi-phase phenomena, reactive transport modeling, and heat transport. The methods I prefer range widely, from analytical and numerical approaches to field applications. Thus, my research includes interdisciplinary approaches, integrating elements of groundwater hydrology, hydrogeochemistry, geology, thermodynamics, and petroleum engineering.

Current projects are:

  1. Role of various heterogeneity structure (e.g., low-k lens, cross-bedding, and channels) on multiphase transport of supercritical CO2, and CO2 trapping mechanisms, and buoyancy-driven migration: To help clarify what processes and properties will maximize CO2 trapping and minimize CO2-buoyant flow, we are collecting field data and performing a systematic analysis of stochastically developed permeability (k) fields.
  2. Non-isothermal effect, heat transport in CO2 sequestration and their application to secure CO2 storage and monitoring: We are establishing the theoretical framework of temperature changes caused by CO2 related chemical reactions (e.g., Joule-Thomson cooling, endothermic water vaporization, and exothermic CO2 dissolution) in the observation wells and testing with numerical simulation tools. The fundamental understanding of thermal processes investigated through this research will be beneficial in the collection and analysis of temperature signals cmeasured from monitoring wells.
  3. Dynamics of cold-water: At CO2 injection sites, CO2 leakage from the storage formation could be catastrophic. CO2 is a highly compressible fluid, typically injected at high pressure and temperature conditions. If compressed CO2 reaches highly permeable conduits such as faults and fractures, CO2 could leak unabated to other formations (e.g. fresh water aquifers) and/or to the surface. Assuming a fast-flow path to the surface, CO2 escaping from the storage formation reaches the surface while experiencing adiabatic expansion, resulting in Joule-Thomson cooling. These eruptive mechanisms are analogues to natural CO2 mechanisms, which are found in CO2-driven cold-water geysers around the world. We are currently investigating the dynamics of CO2 eruption mechanisms in cold-water geysers, and our approaches include field data collection, analyses and computer simulations.
  4. Other topics of interest include equations of states, salt-water intrusion, estimation of regional scale permeability, water-rock interactions, and noble gas (helium) transport in subsurface.

Students interested in graduate studies on coupled processes in groundwater flow emphasis on computation simulations are encouraged to contact Weon Shik Han. Undergraduates interested in research experience and work opportunities should also contact.

Dr. Shangping Xu, Associate Professor

Specializing in colloid filtration in both saturated and unsaturated soil; transport and fate of colloid-bound emerging contaminants on a watershed scale; as well as behavior and toxicity of nanoparticles in the environment.

Shangping Xu

Shangping Xu

Research: My primary research interest lies in the protection of water resources and the supply of safe drinking water. Anthropogenic activities have profoundly altered the hydrological cycle and water qualities on local, regional and global scales. My research group aims at improving our understanding of the transport and fate of colloid-sized particles (mineral particles, particulate organic matter, bacteria and protozoa) as well as colloid-bound contaminants in both natural subsurface environments and engineered systems (i.e. drinking water treatment facility). Our current research projects include:

  • Steric trapping of colloid-sized particles in physically and chemically heterogeneous porous media.
  • Filtration behavior of pathogenic bacteria in both saturated and unsaturated porous media.
  • Transport and fate of colloid-bound emerging contaminants on a watershed scale.
  • Roles of wetland systems in flood control and water quality improvement.
  • Behavior and toxicity of nanoparticles in the environment.
  • Innovative techniques for drinking water purification and wastewater treatment.

Any interested MS or PhD students should feel free to contact any of the faculty members above.