I’m excited to announce that I will be participating in a platform session at the Battelle International Chlorinated Conference in Fort Worth, Texas (May 31- June 4, 2026). The session will focus on the treatment of chlorinated hydrocarbons in low-permeability zones, which represents a significant industry-wide challenge for mature sites seeking closure but unable to meet regulatory requirements due to residual DNAPL and long-term back diffusion. The topic I will present is a case study of a particularly difficult set of circumstances and the design and implementation of a tailored and innovative remedial approach. Some of the key issues involved:
- High-resolution data collection to define the extent of a relatively small (5,000 square foot) area of residual DNAPL present at and just above a thin silt/clay aquitard at depths of 125 feet (55 feet below the top of the water table);
- Data evaluation and modeling to support an alternative to strict MCL-based goals based on measuring the reduction of mass flux downgradient of the residual DNAPL source;
- Thermal modeling which showed that hot water injected at approximately 78°C would achieve a target subsurface temperature of ~60°C within a series of treatment cells, significantly improving DNAPL solubility, reducing viscosity, and lowering interfacial and surface tension in fine-grained soils;
- Enhancement of DNAPL recovery through the application of cosolvents and surfactants to enhance the wettability, further lower the interfacial tension, and further reduce viscosity, allowing for increased residual DNAPL removal from the fine-grained silts and clays;
- Design and installation of ERG’s ThermaCycle™ technology platform and well field architecture that allowed for mass liberation, recovery, and hydraulic controls to minimize the potential for the spread of DNAPL, while maintaining the existing integrity of the relatively thin aquitard.
The platform session also includes several presentations of other case studies at chlorinated sites with fine-grained soils. If you plan on attending the conference this year, I hope you take the time to participate in this session and look forward to seeing you there!
Brett Bowyer, PG