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 oxidizers 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.  

As explained above, DTI has determined that where organic compounds have adsorbed to the soil and especially where they are present as free product or have been “smeared” by groundwater fluctuations, one can expect to also find a source of groundwater pollutants. This technique is used to locate contaminants on every site DTI treats, whether it is a pilot scale demonstration or general application. This technique is initiated by the injection of the Cool-Ox^™ reagent into a matrix engineered to exploit the geologic conditions of the site. The vertical interval of the Injection Point (IP) is designed to include the historic groundwater fluctuation zone where contaminants are usually adsorbed.

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 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) with site characterization in a single process. DTI has proven that once sources are erradicated, the reductions of contaminant concentrations in groundwater can be demonstrated very quickly.