FREQUENTLY ASKED QUESTIONS
Health, Safety and Regulatory Concerns
What is your experience with Fenton's reagent in states where it is not widely accepted to attain state standards, including any precedents for injecting Fenton's reagents into potential drinking waters?
The ISOTEC Process has been accepted by numerous state agencies as a remedial treatment alternative. Most state agencies now consider modified Fenton's reagent and permanganate as an acceptable technology with sodium persulfate gaining increasing acceptance. The state agencies may ask for a lead time of any where from one month to one year prior to commencement of the project to complete review of the proposed remedial action. To date, we have completed projects in Alabama, California, Colorado, Connecticut, Delaware, Florida, Georgia, Indiana, Iowa, Illinois, Kansas, Louisiana, Maine, Maryland, Massachusetts, Michigan, Montana, Nebraska, New Jersey, New York, North Carolina, South Carolina, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, Texas, Utah, Virginia, Washington, Wisconsin and West Virginia and internationally in Japan, Canada and Holland.
What is your field approach to health and safety (designated personnel, monitoring, safety controls, etc.) to achieve the requirement of no reportable OSHA incidents during field activities?
The ISOTEC process was created based on numerous years of both academic and private research in the chemical oxidation field. ISOTEC personnel understand the potential dangers associated with the chemical reaction they are creating, and have completed extensive safety training. As with any activity, by applying safety measures, plus understanding how a process works, limits the potential for any misfortune. ISOTEC personnel work hard every day to maintain our untarnished record of zero accidents in over 15 years of ISCO field implementation.
An ISOTEC injection team typically consists of a field supervisor, along with 2-3 injection specialists. All members of the injection team have completed health and safety training consistent with the Occupational Safety and Health Act (Title 29 of the Code of Federal Regulations 1910.120). ISOTEC supervisors have completed an additional 8 hours of OSHA supervisor training. ISOTEC reagent combinations to be utilized at the site will be tested during a bench-scale lab study. The ISOTEC process utilizes low concentration of reagents under a gravity or slight pressure injection with constant off-gas releases through a site-specific injection apparatus. Reagents utilized are stabilized, with injections performed in a controlled manner to reduce the possibility of any hazard occurring. Pressure and temperature measurements are not typically collected due to ISOTEC’s non-aggressive reactions. However, temperature rises of up to 10 degrees Celsius have been noted for a short period (<24 hours), and slight applied pressure is used only within less permeable aquifers.
What is the potential for surface breakout of reagents during injection activities?
Safety is a priority with the ISOTEC process, which uses a relatively non-aggressive reaction chemistry. Possible side effects such as surface breakout or lateral migration of treatment reagents and/or off-gases occur with aggressive reaction type oxidative processes utilizing high concentration reagents under a constant pressurized condition. This type of reaction creates a significant temperature rise and an enormous amount of carbon dioxide and/or oxygen off-gas, which push vapors and contaminants within the subsurface. ISOTEC does not utilize this approach. Reagents utilized by ISOTEC are stabilized and at a low concentration, with injection in a controlled manner to reduce the possibility of surface breakout or lateral migration. Furthermore, at sites with shallow depth of ground water, extreme caution must be exercised while injecting reagents as the mounding effect created raises the ground water elevation to close proximity of the surface. Again, the stabilized ISOTEC reagents utilized along with control of the injection process limits these concerns.
Will the use of Fenton’s reagent increase the groundwater concentrations of arsenic, chromium, iron and/or manganese, and will any of the by-products of Fenton’s reagent reactions create compounds not now present in the groundwater? If so, what are the expected concentrations of these compounds?
Conventional Fenton’s reaction occurs at or within an acidic pH range, and therefore, would allow metals to leach into the aquifer. The ISOTEC modified Fenton's process, with its neutral pH based reagents, should not create a condition to allow leaching of metals.
Can injections be done safely indoors? Can injections be designed to prevent damage to wooden structures?
ISOTEC has worked at several sites where the injection activities were performed indoors. We have treated petroleum hydrocarbon contamination resulting from a heating oil spill in the basement of a house that was occupied during the treatment program (See Case Study 8).
Another project in northern New Jersey was a vacant warehouse contaminated with PCE and Cis-DCE. We have achieved substantial contaminant destruction and the case is currently being reviewed by NJDEP for closure. Currently, we are working on another project in an industrial warehouse (currently occupied) in New Jersey. We have successfully performed a pilot program at a former car dealership (vacant) in Boston. We have also performed injection activities inside an existing seasonal boutique store (former dry cleaners) in upstate New York.
The use of low reagent concentrations coupled with a milder reaction limits any concerns associated with damage of wooden structures. No adverse impacts were reported at any of our previous sites. Vapor generation is not a major concern with our process mainly due to the low concentration of reagents that we use. Our catalysts are prepared for use at circum-neutral pH conditions and are not acidic in nature. All previous monitoring activities conducted for vapor generation during ISOTEC injections have yielded negative results. A site specific Health and Safety Plan (HASP) will be prepared prior to initiating field activities.
Why should you use the ISOTEC℠ Process?
When reviewing a site for the ISOTEC process, we first utilize a common sense approach to evaluate and design a treatment program. In some cases, ISCO may not be the most practical remedial treatment alternative, as is the case with large layers of free product (>2") and associated large amount of reagents needed to treat such. For any site, ISOTEC first presents their approach for remedial treatment utilizing a chemical oxidation process. The approach incorporates dividing the test area into small treatment zones, along with several treatment applications. ISOTEC designs their treatment programs to not only meet the desired "Corrective Action Objectives" proposed, but to reduce the contaminants of concern to as close to a non-detectable level as possible.
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