Our Team

Jeff Roberts, M.Sc. | Operations Manager
Jeff is the Operations Manager at SiREM with extensive technical experience in the laboratory assessment and field implementation of soil, sediment and groundwater remediation technologies at sites containing contaminants including chlorinated solvents, petroleum hydrocarbons, emerging contaminants and other recalcitrant compounds. Over the past 18 years he has conducted and managed hundreds of bench-scale batch and column treatability studies and has technical experience in the growth, scale up and field implementation of several anaerobic microbial cultures for bioremediation remedies. Jeff has several years of passive sampling experience and was a lead member in the development of the SP3 sampler.

Sandra Dworatzek, M.Sc. | Senior Principal
Sandra is a Senior Principal Scientist with more than 25 years of experience in bioremediation of chlorinated solvents, petroleum hydrocarbons, emerging contaminants and other recalcitrant compounds. She has specific technical experience in the design of laboratory treatability studies, the scale up of growth of aerobic and anaerobic microbial cultures for bioaugmentation laboratory and field pilot tests, and evaluation of aerobic and anaerobic bioremediation, zero valent iron and chemical oxidation technologies in the laboratory. She currently provides senior technical oversight of laboratory treatability studies and the development and scaleup of new bioaugmentation cultures, including novel cultures for BTEX compounds under anaerobic conditions and aerobic 1,4-dioxane bioremediation. Sandra currently is the industry lead on a Genome Canada funded project for the commercialization of anaerobic BTEX degrading cultures.

Phil Dennis, M.A.Sc. | Senior Principal
Phil Dennis has over 30 years of experience in research and management of molecular biology, microbiology, and environmental remediation laboratories. Phil holds a Master of Applied Science in Civil Engineering from the University of Toronto and an Honours B.Sc. in Molecular Biology and Genetics from the University of Guelph. Phil is a founding member of SiREM and, as a Senior Principal Scientist, now focuses on managing research and development and directing molecular genetic testing services. Phil focuses on analyzing and characterizing environmental microbial communities using molecular genetic methods.

Brent G. Pautler, Ph.D. | Chemistry Services Manager
Brent received his Ph.D. in environmental analytical chemistry in 2013 where he gained advanced technical experience in spectroscopy, chromatography, mass spectrometry, passive sampling, and chemistry informatics. Throughout his career, he has worked with scientists, engineers, and consultants, applying his chemistry and information technology expertise to help them solve unique problems in the laboratory and the field. His role includes managing and advancing SiREM’s passive sampling portfolio, analytical testing services, and compound specific isotope analysis (CSIA) services.

Ximena Druar, B.Sc. | Genetic Testing Manager
Ximena joined SiREM in 2002 as one of SiREM’s first employees and now serves as the Genetic Testing Supervisor where she oversees and coordinates the day-to-day work for Gene-Trac® testing. Her work includes managing deployment of over 60 tests and next-generation sequencing, as well as supervising laboratory technicians and assistants. In addition, Ximena is a client liaison and approves and issues reports, proposals, and invoices.

Rosemary Le, Ph.D. | Laboratory Supervisor
Rosemary is a Science Professional at SiREM. She joined the SiREM Knoxville location in 2022, bringing over 13 years of experience of lab management in the fields of chemical engineering, biotechnology, sustainable energy research, and molecular biology. Rosemary’s areas of expertise include treatability studies, method development, proposal writing, and research projects, and she is also playing a part in one of SiREM’s newest service areas, anti-microbial efficacy testing. She is adept at adapting and translating established ASTM and EPA methodology, or peer-reviewed literature into protocols for novel treatments.

Michael Healey, B.Sc. | Treatability Manager
Michael is the Treatability Manager at SiREM and has been with the team since 2013. With over a decade of experience, Michael has managed numerous bench-scale studies evaluating remediation technologies for contaminants including chlorinated solvents, petroleum hydrocarbons, emerging contaminants and other recalcitrant compounds in soil, sediment, and groundwater. Michael has several years of passive sampling experience and was a lead member in the development and commercialization of the SP3™ sampler.

Jennifer Webb, M.Sc. | Laboratory Manager
Jennifer is a Laboratory Manager at SiREM with more than 17 years of experience in microbiology where she has developed 9 commercial cultures, over 30 research cultures and coordinates R&D collaborations with researchers globally. She was instrumental in the development of a benzene, toluene and o-xylene culture and is presently developing an ethylbenzene culture to complete the BTEX suite. Alongside culture development, Jennifer has conducted and managed biotreatability and ISCO/NOD studies for more than 17 years.

Corey Scales, B.Sc. | Bioaugmentation Production Manager
Corey has technical experience in the growth, scale-up, and field implementation of several anaerobic microbial bioaugmentation cultures to degrade compounds including chlorinated solvents, petroleum hydrocarbons, and other recalcitrant compounds. Over the past seven years, he has provided technical support throughout the planning, injection, post-injection monitoring and data analysis stages for hundreds of field bioaugmentation events. He is focused on providing customer support and insights to optimize bioremediation success.
Our Laboratory and Technical Support Team
Our creative thinkers work together every day to find solutions to our clients’ toughest problems. We are experts in chemistry, biology, microbiology, and related fields who collaborate to find new solutions and apply technology and science in novel ways to find better answers for our clients.






















