I am part of a small but dedicated research collaboration investigating various aspects of riverine and groundwater biogeochemistry. The following are some of the current active areas of research:
Causes and occurrences of diel (24-h) processes in pH neutral to alkaline streams and how these processes influence daily changes in the concentration of trace metals and arsenic. We are specifically focusing on sediment (biofilm) – water interactions of metals such as Mn2+, Zn2+ Cu2+ and others.
Investigations of the mechanisms controlling metals transport and diel processes in acidic streams affected by acid rock drainage or natural geothermal waters. This work has been done in mining impacted streams in Montana as well as Rio Tinto, Spain and Rio Agrio, Argentina.
Use of stable isotopes (18O and 13C) of dissolved oxygen, dissolved inorganic carbon and dissolved organic carbon as tracers of processes affecting carbon cycling in streams. The use of stable isotopes is powerful tool to investigate diel processes but the quantitative relationships are not well understood.
Investigations of the mechanisms controlling dissolved oxygen depletion in groundwater systems using stable isotopes – biotic vs. abiotic. This is a relatively new area of work but as groundwater resources become more important we need to better understand the fundamental science of the process acting on these reservoirs.
Recent investigations have followed the occurrence, movement and sources of organic wastewater chemicals in groundwater in the Butte Summit Valley. This project has been in collaboration with the Montana Bureau of Mines and Geology.
Seasonally ice-covered lakes in temperate environments have unique geochemical and microbiological structures during winter. Our research collaboration is investigating the linkages between under-ice chemical/physical conditions with depth to the microbiological communities at Georgetown Lake near Phillipsburg, MT.
