A practical upscaling of subsurface reactive transport

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Groundwater is an important drinking water source for many communities. Who depends on groundwater for drinking water ? Three of four American cities, 95% of the rural American population, and over half of all Americans. Wide scale contamination of groundwater threatens many of these sources. The state-of-the-science for cleaning up contaminated groundwater is mired in 1950s technology because the pollutants and the flowing groundwaters in which they occur are out of sight and very difficult to monitor. This makes it particularly difficult to design so-called 'in situ' clean-up methods, that rely on injecting mixtures into the subsurface to make chemical reactions underground that convert the contaminants to non-toxic products.The problem to be studied in this project is how groundwater clean-up happens underground. The project will use a recently discovered method of tracking the moving front between the contaminated ('plume') and the non-contaminated groundwater as a basis for predicting the overall rate of chemical transformation in situ. This new method is a recent invention from the theory of turbulence, a field that has challenged human minds since the time of DaVinci, and it promises to provide a much more accurate way of accounting the overall rate of clean-up, even when it is difficult to know exactly the location of the contaminant plume. This project includes both controlled experiments in the laboratory and field site testing to complete the development of this method of designing groundwater clean-up. This innovative and powerful approach does not require the site manager to know exactly where the plume is, like other methods, but it only requires the total surface area of the plume. The broader significance of this research includes: development of new methods to help federal and state agencies, cities, groundwater contamination responsible parties, and anyone responsible for groundwater quality, to design and manage in situ groundwater remediation strategies all over the United States. This project shares the work with learning people at all levels from Kindergarten to College, in order to achieve broad training goals. The project involves both undergraduate and graduate students in interdisciplinary education, includes classes with approximately 75 K-12 students as well as their teachers per year involved in different aspects of engineering and environmental processes in soils through one-day hands-on field trips to the UC Davis campus, and expansion of two UC Davis graduate courses to include material learned in this project.