GROUND FREEZING FOR
ENVIRONMENTAL APPLICATIONS

We have exclusive patents for the freezing ground to contain (CRYOCELL^®) or remove (ISOCELL^™) contaminated soil and groundwater. These technologies have been tested in the laboratory as well as in the field. Frozen soil barriers to contain high level radiation has been successfully tested by the U.S. Department of Energy (DOE) at their Oak Ridge, Tennessee facility. This technology is now listed as one of DOE's top ten barrier technologies and is being seriously considered at several other DOE sites.

Advantages of Frozen Soil Barriers at Contaminated Sites

• Very Low Permeability—The permeability of frozen soil has been extensively tested both in the lab and in the field and found to be very low (less than 10^-10 cm/sec). Field evidence indicates no migration of tritium, metals, hydrocarbons or other types of contaminants into frozen ground at sites where groundwater contamination has been contained naturally by permafrost for up to 30 years. Diffusion tests on samples containing plutonium and other radioactive contamination demonstrate that frozen ground has extremely low diffusion.

• Works in All Ground Conditions—Frozen soil barriers work almost anywhere a 3-inch-diameter pipe can be installed. This includes running sands, cobbles and boulders, fractured bedrock, peat, clay and soils containing debris. Freezing temperatures penetrate all materials, thus ensuring a continuous barrier. We can install freeze pipes near, around or below almost any type of utility without disruption of service.

• Ground Freezing Works in Arid Soils—Even in unsaturated conditions, ground freezing is effective as a barrier. As contaminated fluid from say a leaking tank flows into the frozen zone, it quickly freezes into a solid. If needed, water can be selectively added near the freeze pipes to locally increase the ice content and reduce the permeability even further.

• Temporary or Long Term—Frozen soil barriers can be used for temporary containment to prevent offsite migration until a suitable treatment is developed or during the remediation process itself. This, of course, will significantly reduce the amount of contaminated groundwater and soil that must eventually be remediated thereby reducing cleanup and liability costs. Ground freezing can also be used as a long term barrier. With SoilFreeze's newer ground freezing equipment, installation and operation costs have been significantly reduced. Also, electric costs to maintain a frozen soil barrier are relatively low.

• Can Be Completely Removed—Unlike most other barriers, a frozen soil barrier can be completely removed after the site is remediated simply by turning off the electricity and allowing the ground to thaw naturally. The site is left in its pre-remediation state.

• Fully Monitorable—Frozen soil barriers can be monitored in many ways to verify that it is working. These include temperature sensors to verify the thickness of the frozen ground and pressure sensors to identify problems with the freeze system. The integrity of the frozen wall can be tested by sampling water from piezometers and using geophysical techniques, including ground penetrating radar, electromagnetic response, and acoustical response.

CRYOCELL^® for Containment

• Containment of Contaminated Soil/Groundwater
  -No Natural Groundwater Cutoff at Shallow Depth
• Containment of Contaminated Soil/Groundwater
  -No Natural Groundwater Cutoff at Shallow Depth—Small Site
• Containment of Contaminated Soil/Groundwater
  -No Natural Groundwater Cutoff at Shallow Depth—Large Site
• Complete Stabilization of Contaminated Soil/Groundwater
  -Shallow Contamination
• Complete Stabilization of Contaminated Soil/Groundwater
  -Deep Contamination
• Funnel and Gate

Other Information on CRYOCELL^®

ISOCELL^™ for Removal of Contamination

CRYOSWEEP^™ for In-situ Remediation

Brownfield Redevelopment

Emergency Response Service

An additional product to be marketed is an emergency response service, which provides a containment system to be activated in the event of need at sites executing a Remedial Action (RA) cleanup or in the event of an accidental spillage or failure of a remediation technology.

A frozen soil barrier containment system engineered to site specific conditions utilizing local equipment, labor and knowledge for rapid deployment represents a viable contingency plan for emergency situations. Such contingency plans are many times required by site regulators and desirable to stakeholders. Preferably standards and specifications for any emergency backup systems will be determined and agreed with regulators and stakeholders at the time of contracting the service. Deployment of the preapproved system would be the only action item when an emergency occurs.

This is an excellent service to be marketed to companies which are bidding or who have signed contracts with the EPA to provide overall emergency response services in an entire EPA region. In the private sector, such a service, complete with a comprehensive implementation plan, negotiated and approved with the responsible regulatory authority, may provide the basis for negotiating lower insurance premiums and reduced set asides (liability reserves) for site owners and potentially responsible parties (PRP's). The service can evolve to a subscription program whereby a subscribing client pays an annual fee to the Company for limited license of the technology to be used under the auspices of the existing Record of Decision (ROD).

A specific example for which an emergency response containment system is desirable is within the DOE tank remediation program. For instance, at the Hanford Reservation in Richland, Washington, the 200E and 200W operating areas have 177 buried tanks from which the radioactive waste is programmed to be removed and processed. Included in the 177 total tanks there are 12 tank farms with 149 single-shell tanks, and 6 newer tank farms with 28 double-shell tanks. Every one of the 12 single-shell tank farms is known to have leaking tanks. The proposed program of cleanup at this stage is to introduce hydraulic sluicing to the tanks and pump and treat the extracted wastes. Being that a significant number of the tanks are known to be leaking, it is apparent that a high risk of additional subsurface leakage could be precipitated by a sluicing process. A CRYOCELL emergency response system would allow for rapid containment of any subsurface migrating wastes thus protecting the groundwaters from contamination.