Finding the Sources
DTI’s principles have for some time, understood the reality that "unless the soil sources are located and destroyed, attempts to mitigate groundwater contaminants are destined for failure." A characteristic of the Cool-Ox® Technology is the production of a lather (resembling dirty shaving cream), when the reagent reacts with organic contaminants. This reaction proceeds when any organic compound reacts with hydrogen peroxide derived oxidation and reductive agents in an in-situ environment, but this reaction is useful only when it can be controlled. If the reaction is too robust (fast), even a trained observer cannot distinguish highly concentrated organics (sources areas) from dissolved compounds. Once understood, it immediately became apparent that the slow evolution of foam from the injection points (where contaminants were present) could be an extremely useful and inexpensive forensic tool. It should also be noted that, the Cool-Ox® Process is the only remedial technology that provides actual site remediation at the same time as the site characteristic work is being conducted. The illustration below depicts the application of the this technique.
If contaminants are present at the IP, the evolution of foam reveals a source area. At IPs where no or little foam is observed, the contaminants if present, may not constitute a continuing threat to groundwater.
During the treatment process it is quite normal to adjust the injection techniques and injection point spacing to compensate for varying site conditions. This feature is unique to Cool-Ox® Technology. The photograph below depicts the lather-like foam that is reflected to the surface where contaminants are present.
Once the sources have been delineated, the volume and formulation of the reagent can be adjusted so as to deliver the maximum oxidizing/reducing capability where it will produce the best results. At each site, DTI field chemists watch for these reaction profiles to highlight the contaminant sources. Experience has shown that undiscovered perched or smeared contaminant sources are the norm rather than the exception particularly, at service station sites. Where present, these potential source(s) will be located and saturated with the Cool-Ox® reagents. This aggressive method of treatment has proven very effective and is the only technology that combines In-Situ Chemical Oxidation (ISCO) and In-Situ Chemical Reduction (ISCR) with site characterization in a single process. DTI has proven that once sources are eradicated, the reductions of contaminant concentrations in groundwater can be demonstrated very quickly.