Terry Hazen, Ph.D. Senior Staff Scientist and Department Head Ecology Department Earth Sciences Division Lawrence Berkley National Laboratory

Dr. Hazen received his B. S. and M. S. degrees in Interdepartmental Biology from Michigan State University. His Ph.D. is from Wake Forest University in Microbial Ecology. His dissertation research was done at the DOE Savannah River Site on the effects of nuclear reactor cooling waters on bacteria, alligators and fish. Dr. Hazen was Professor, Chairman of Biology and Director of Graduate Studies at the University of Puerto Rico for 8 years. He was Fellow Scientist at the Savannah River Site 11 years, the last 5 as manager of the Biotechnology Group within the Savannah River Technology Center. In 1998, Dr. Hazen joined the LBNL Earth Sciences Division as Head of the Ecology Department and Lead Scientist for the Environmental Remediation Technology Program. In 1999, he was appointed as head of the Center for Environmental Biotechnology. In 2002 he founded and became co-director of the Virtual Institute for Microbial Stress and Survival after receiving a $36.6 million competitive award from the DOE Genomes to Life Program. He is a fellow of the American Academy of Microbiology and has authored more than 191 scientific publications, not including more than 552 abstracts and chapters in several books. He has also given more than 879 scientific presentations, 75% of them invited. Dr. Hazen received the 1995 R&D 100 Award, 1996 R&D 100 Award, and the 1996 Federal Laboratory Consortium Excellence in Technology Transfer for bioremediation technologies. In 2005 he was one of the first four scientists awarded DOE's Distinquished Scientist. He has patents on 5 bioremediation processes that are being used in 25 states and Europe, these technologies have been licensed to more than 30 companies. He has chaired DOE's Environmental Remediation Science Program Field Research Review Panel since it's inception in 1999. Dr. Hazen has acted as an expert reviewer for 25 different scientific journals and 14 federal research granting agencies. His area of specialty is environmental microbiology, especially as it relates to bioremediation. He has supervised and consulted on the implementation of bioremediation at more than 50 sites.

Presentation Description
Field-Integrated Studies of Long-Term Sustainability of Chromium Bioreduction at Hanford 100H Site
HRC was injected in Hanford sediments (through the injection borehole over the depth interval from 44 ft to 50 ft) to stimulate immobilization of Cr(VI) in August 2004. Within the next 2-3 weeks, the HRC injection induced a 2-order-of-magnitude increase in biomass-up to more than 107 cells ml-1, which remained high for over 3 years. Using sediment samples, we determined the presence of several types of bacteria, including Bacillus/Arthrobacter and Geobacter species. These bacteria are known to withstand high concentrations of heavy metals, metabolize recalcitrant chlorinated compounds, and reduce or sorb hexavalent chromium. The HRC injection also induced the onset of reducing biogeochemical conditions-redox potential decreased from +240 to -130 mV and dissolved oxygen (DO) was completely removed. We have found that the HRC breakdown products cause the microbial population to deplete sequentially the oxygen, nitrate, iron(III), sulfate, and carbon dioxide (transiently). Once the nitrate was depleted we began to see the transformation of Cr(VI) species to Cr(III) species that were precipitated on soil particle surfaces. Sulfate and iron microbial reducers have apparently maintaining Cr(VI) reduction below the drinking water standards in the injection well for more than 3.5 years. Cr(VI) concentration in the monitoring well decreased below drinking water MCL and remained at this level for 3 years. Iron reduction is still active more then three years after the injection, and the presence of Fe(II) suggests active Cr(IV) reducing conditions. Some HRC or its byproducts may still remain in the area surrounding the injection well; however, it may also be possible that the microbial community is dependent on cryptic growth.