Photo of Mary Ellen Tucillo

Mary Ellen Tuccillo

Senior Environmental Scientist

Staring out of an airplane window not long after my first geology course, I was amazed at how the landscape features jumped out at me. I saw clearly how river flow, sediment, and time had interacted. That wonder is still with me as I apply what I know about geology and geochemistry to protect our nation’s groundwater, drinking water, and infrastructure. My work is diverse, and I like it that way because it allows me to bring a deep understanding of the earth and environmental sciences to a wide array of subsurface and surface environmental problems.


Dr. Mary Ellen Tuccillo is a senior environmental scientist with 20 years of experience in basic and applied research and regulatory implementation. With a strong background in geochemistry, she supports work on subsurface biogeochemical processes, soil and groundwater contamination, aquifer recharge, underground injection, geologic carbon sequestration, source water protection, and the impacts of wet weather flows. She also has extensive experience in sediment and groundwater sampling and analysis. She has led dozens of projects and tasks for the U.S. Environmental Protection Agency, the Water Research Foundation, and others, and has presented her work at workshops and national conferences. She has also served as a research fellow with EPA's Urban Watershed Management Branch.

In her research and project work, Dr. Tuccillo has evaluated patterns of lead isotopes in industrial soils, the use of Fenton’s chemistry for degradation of PCBs in soil, and biodegradation rates for organic compounds in groundwater. She has also evaluated proposed remedial alternatives for landfill leachate, vanadium in coal ash leachate, and volatile organic compounds in groundwater. She has researched microbially mediated redox processes in groundwater, the speciation and removal of heavy metals in suburban runoff, and airport stormwater management. For EPA’s Underground Injection Control program, she has performed significant work on Class VI wells for geologic sequestration of carbon dioxide. For the National Water Reuse Action Plan, she supported EPA in developing a state-of-the-science review on water reuse in aquifer storage and recovery and enhanced aquifer recharge. Also for EPA, she served as lead wastewater author for the agency’s Assessment of the Potential Impacts of Hydraulic Fracturing for Oil and Gas on Drinking Water Resource. Mary Ellen holds a B.S. in geology from Yale University, an M.S. in geology from the University of Michigan, and a Ph.D. in environmental sciences from the University of Virginia. When not working, she enjoys hiking, photography, and playing the violin.