This project studies evaporation, groundwater mixing, surface-water circulation, groundwater/surface-water interactions, contaminant migration and remediation, and other hydrochemical and biologic processes. The isotope variations are related to (1) purely physical processes, (2) heterogeneous chemical equilibria, and (3) reaction kinetics. The isotope effects of many of these processes are not sufficiently understood or quantified to make the most effective use of stable isotope techniques in hydrologic research. This project aims to develop theoretical and instrumental mass spectrometric techniques through experimental investigation, and to test applications in suitable field locations to improve the utility of light stable isotope phenomena in hydrogeologic and biochemical studies.
Specific approaches of the project include (1) development of new or modified techniques for isotope analysis, (2) preparation and calibration of reference materials for international calibration of isotope-ratio measurements, (3) development of information management systems and quality control guidelines for stable isotope laboratories, and (4) testing applications of isotope measurements and theory, along with other types of hydrochemical data, in representative field settings. Experimental results and field data are used to improve understanding and develop predictive theoretical models of the processes involved.
