When solving complex soil and groundwater assessment and remediation issues, our senior hydrogeologist, Dr. Michael Sklash, often says, “the puzzle pieces must fit together.” No one single piece of the puzzle can tell the whole story, but each piece, when fit together as a whole, can be valuable in understanding subsurface contamination.

One of those potential pieces of the puzzle will be addressed at an upcoming conference by Dr. Fatemeh Vakili, an isotope hydrogeologist at Dragun.  Her presentation is formally titled, “Chlorine and Hydrogen Isotope Fractionation in Chlorinated Ethenes during Physical Processes.”  Below is Dr. Vakili’s explanation of her upcoming presentation:

Poster Presentation

Dr. Fatemeh Vakili, an isotope hydrogeologist at Dragun

“In contaminant hydrogeology, confirmation of sorption processes in the subsurface helps in determining whether monitored natural attenuation is a viable remediation technique. Back-diffusion of contaminants that previously diffused into low permeability zones (e.g., clay aquitards or bedrock) can act as a secondary source of contamination and, therefore, is important in evaluating the remedial approach. The literature generally indicates that physical processes such as sorption, diffusion, and back-diffusion do not affect the isotopic ratios in chlorinated ethenes. This conclusion, however, is based only on the behavior of the stable carbon isotopes in the chlorinated ethenes.

My study (1) confirmed that the above-mentioned processes have a small, but measurable, effect on stable chlorine isotopes and (2) indicated that these processes have a significant effect on stable hydrogen isotopes in chlorinated ethenes. Therefore, compound specific hydrogen isotope analysis in chlorinated ethenes is a potentially-powerful tool in understanding contaminant sorption and back-diffusion from low permeability zones in the subsurface.”

Here is a link to the Battelle Eleventh International Conference on Remediation of Chlorinated and Recalcitrant Compounds. 

If you have additional questions about this presentation, please contact our office at 248-932-0228 or in Canada at 519-979-7300. For more information on addressing complex soil and groundwater issues, contact Dr. Michael Sklash, P. Eng.