Events login

Main Events Calendar

Warning Icon This event is in the past.
February 15, 2019 | 2:30 p.m. - 3:30 p.m.
Category: Seminar
Location: Old Main #0121 | Map
4841 Cass
Detroit, MI 48201
Cost: Free
Audience: Academic Staff, Alumni, Community, Current Graduate Students, Current Undergraduate Students, Faculty, Parents, Prospective Students, Staff

The Earth and Environmental Science Seminar Series presents: "Assessing the vulnerability of public supply wells to near-surface contamination using geochemistry, microbiology, & geomechanics" with Dr. Christopher A. Gellasch, PhD, Assistant Professor, Department of Geography and Geology, Eastern Michigan University.

Friday February 15th at 2:30pm

Old Main Room 0121 (in tbe basement near the front entrance)

Reception and refreshments to precede 40 – 50 min seminar followed by time for questions

Abstract:  Approximately 1/3 of the U.S. population uses public supply wells as their drinking water source and recently a greater focus has been placed on assessing the risk of contaminants entering these wells. A variety of methods can be used to better understand the mechanisms that control the transport of near-surface contaminants into bedrock multi-aquifer systems allowing researchers to develop effective methods for assessing well vulnerability and public health risk from this water. At an urban field site in Madison, Wisconsin, fractures in the sandstone aquifer system may have an important role in the transport of sewer-derived wastewater contaminants. Data from pressure transducers in monitoring wells at varying depths and distances from a pumping well suggest that geomechanically-derived groundwater pressure changes propagate rapidly through fractures to influence wells 100s of meters from the pumping well. The pattern of pressure change propagation can be used to better define fracture connectivity in the aquifer system and may serve as preferential flow pathways that allow contaminants to rapidly move through the subsurface and reach the public supply well. Time sequenced groundwater sampling for chemical and microbiological wastewater indicators is another useful tool for characterizing transport within an aquifer system. The use of polymerase chain reaction methods allows for the detection of human enteric viruses at extremely low concentrations in groundwater. There is an apparent connection between recharge events (rainfall or snowmelt) and increased flow in sanitary sewers. Based on limited data, these increased wastewater flows appear linked with virus detection in groundwater at short times after these events.

Biography: Christopher Gellasch is a hydrogeologist who is currently an assistant professor at Eastern Michigan University in Ypsilanti, MI. He received his Ph.D. in Geology from the University of Wisconsin-Madison, M.S. in Geological Sciences from Indiana University, and a B.S. in Geology from Eastern Michigan University. His research combines aspects of hydrogeology, environmental engineering, and public health to determine the most likely pathways for near-surface contaminants to migrate through the subsurface and impact public supply wells.

For more information about this event, please contact Shirley Papuga at 313-577-2506.