Earth Sciences Division (ESD) Department of Energy (DOE) Lawrence Berkeley National Laboratory (LBNL)

Earth Sciences Division Staff: Aaron Slowey

Aaron Slowey

Aaron Slowey

Project Scientist

Geochemistry Department






Biographical Summary

Aaron Slowey began his training in 1995 as a civil engineering student at Northeastern University, where he accumulated two years of work experience at consultancies helping engineers design stormwater and water treatment systems.   He continued his training at UC Berkeley in 2000, with a full out-of-state tuition scholarship, focusing on hydrogeology and the physical science (geochemistry) of soils.  In 2001, he continued his studies at Stanford, focused on molecular-level processes at mineral-water interfaces, and began working on inoperative mining site characterizationa and remedial investigations in collaboration with the U.S. Geological Survey.

From 2006-2007, as an independent consultant, Aaron investigated inopertive mine sites throughout California, providing bureaus of the Department of Interior data and interpretation to manage sites (clients included the USGS and a private landowner).  In 2011-2012, he spectroscopically analyzed mercury in soils to help the Environmental Protection Agency validate a health risk assessment of a community situated near an abandoned mine.

In late 2007, he was awarded a Mendenhall Postdoctoral Fellowship at the USGS to clarify why we currently cannot predict how much mercury, out of the tens of tons emitted by mining and fossil fuel processes every year, ends up in the aquatic food web.  Through an experimental approach incorporating spectroscopic (EXAFS and PCS/DLS) and advanced chemical tools (in situ microelectrode voltammetry), this groundbreaking work redefines the crucial interrelationship between organic matter, sulfide, and mercury that controls the methylation of mercury in most aquatic systems (presentation video).  He concurrently developed voltammetric microsensors and fully demystified how to use these sensors to quantify individual redox-active constituents in the pore water of soil and sediment.

In 2009, as a Research Chemist at USGS, Aaron was awarded a grant from the Strategic Environmental Research & Development program of the Department of Defense to lead 5 scientists to develop a next-generation metal bioavailability sensor for sediments using chronopotentiometry (more...). 

At LBNL, he is completing two projects on chromium transport through porous media utilizing medical radiotracer imaging to visualize water flow and biogeochemical process.  He is also supporting solid-phase metal speciation in dynamic laboratory systems using synchrotron-based X-ray spectroscopy and is part of a carbon geochemistry group within the Sustainable Systems Scientific Focus Area.


  • Ph.D., Geological & Environmental Sciences, Stanford University (2006)
  • M.S., Environmental Engineering, UC Berkeley (2001)
  • B.S. Civil Engineering, Northeastern University (2000), summar cum laude with honors

Professional Experience

  • Research Chemist, U.S. Geological Survey, Water Resources, Menlo Park, California, 2009-2011.  Physicochemically parameterized dissolved metal (Cu, Pb, Zn)-organic interactions using non-perturbing electrochemical methods; fabricated microelectrodes to simultaneously quantify dissolved oxygen, sulfide, iron, and manganese in sediment pore water using voltammetry
  • Postdoctoral Fellow, U.S. Geological Survey, Geology, Menlo Park, California, 2007-2009.  Measured the kinetics of mercury-sulfide precipitation and the molecular-to-nanometer-scale structure of mercury-sulfide nanoparticles using photon scattering and synchrotron-based X-ray absorption spectroscopy (XAS) and determined how aquatic dissolved organic matter affects these ecotoxicological processes; determined sulfur speciation in chromatographic isolates of natural organic matter using XAS
  • Consultant, Public Resource Associates, Reno, Nevada, 2006-2007.  Characterized mercury, nickel, iron, and sulfur geochemistry in a network of cinnabar mine drainage streams in Napa, California and wrote an interpretive report
  • Contractor, U.S. Geological Survey, Geology, Menlo Park, California, 2006-2007.  Designed and conducted synoptic water, soil, and sediment sampling at an inoperative silver and gold mining district in Bodie, California and Aurora, Nevada, analyzed samples for dissolved sulfide and iron, performed solid-phase chemical extractions for iron, modeled stream geochemistry with the Geochemist’s Workbench; Interpreted previously collected field data and wrote reports on mercury transport in mine drainage
  • Research Assistant, Stanford University, Stanford California, Ph.D. Advisor: Gordon E. Brown, Jr., 2001-2006.  Determined the molecular speciation of mercury and arsenic in gold and cinnabar mine waste using XAS; performed column experiments to quantify the extent of colloidal transport of mercury and arsenic under simulated phytoremediated conditions and speciated mobile mercury and arsenic phases.  Designed and built a stirred flow reactor to apply chemical gradients to mineral suspensions; quantified mercury speciation using XAS under an induced sulfide gradient in iron-oxyhydroxide suspensions, including the mechanism of mercury adsorption to iron-oxyhydroxide; quantified liquid and solid-phase iron and sulfur; determined sulfur speciation with XAS
  • Teaching assistant, Environmental Geochemistry, Stanford University, Earth Materials, Stanford University, 2001-2002
  • Workshop assistant, Stanford Environmental Molecular Science Institute, 2005 and 2009
  • Mentor, Mentored M.Sc. candidate in the Department of Earth Systems at Stanford University, 2004-2005
  • Hydrogeology intern, Santa Clara Valley Water District, San Jose, California, 2001.  Briefed environmental data and interpretive reports; modeled subsurface hydraulic conductivity and perchlorate transport
  • Environmental consultant, Massachusetts Water Resources Authority, Boston, Massachusetts, 2000.  Studied the effect of ozone on the kinetics of chloramine decay during drinking water disinfection
  • Engineering intern, Montgomery Watson, Boston, Massachusetts, 1998-2000.  Operated an ozonation and filtration water treatment pilot plant, and performed routine water quality analyses (Summer-Fall 1998); inspected design drawings, documents, and performed field reconnaissance during a combined sewer system rehabilitation project (Spring 1999 and Winter 2000)
  • Engineering intern, Camp Dresser & McKee, Cambridge, Massachusetts, Winter 1998.  Edited Auto CAD drawings for landscape architecture projects; analyzed landfill monitoring well data


  1. Principal Investigator, Strategic Environmental Research and Development Program Grant, U.S. Department of Defense ($150k) 2010-2011
  2. Venture Capital Grant ($30k; U.S. Geological Survey), 2010
  3. Mendenhall postdoctoral fellowship (U.S. Geological Survey), 2007-2009
  4. U.S. Geological Survey Mineral Resources Program research grant (Stanford University), 2005-2006
  5. Full out-of-state tuition scholarship (University of California Berkeley), 2001
  6. Engineer in Training, Commonwealth of Massachusetts, 2000