Managing the negative impacts of groundwater flow on electrothermal remediation

Rapid groundwater fluxes often influence subsurface temperature distributions during in situ thermal remediation using electrothermal or conduction heating technologies. This study used a numerical approach to evaluate the impact of groundwater flow on electrothermal heating, as well as the effectiveness of several upgradient heat loss management strategies, in a hypothetical treatment volume. Design alternatives using upgradient (i) hydraulic barriers, (ii) physical barriers, and (iii) increased energy input are evaluated. Results indicate that target temperatures can be achieved, despite the presence of local groundwater flow velocities greater than 0.3 m/day, through the careful design and implementation of the alternatives evaluated. However, physical barriers need to be designed to prevent groundwater flow through the heated volume to be effective. Field data from an electrothermal application are also presented, where boiling temperatures were achieved after steam injection and upgradient pumping wells were implemented.