Superfund Innovative Technology Evaluation (SITE)
Note: EPA no longer updates this information, but it may be useful as a reference or resource.
Research Institute Contained Recovery of Oily Wastes (CROW) Process
This report presents performance and economic data from a Superfund Innovative Technology Evaluation (SITE) Program demonstration of the Contained Recovery of Oily Wastes (CROW) process. The demonstration evaluated the technology’s ability to treat subsurface accumulations of oily wastes. The results of bench- and pilot-scale testing of the technology are presented as appendices to this report.
The CROW process was developed by the Western Research Institute as an in situ remediation technology to mobilize and remove oily waste accumulations from the subsurface. The technology involves the injection of heated water into the subsurface to mobilize oily wastes, which are removed from the subsurface through recovery wells. The oily waste is separated from the groundwater and is disposed of or recycled. A portion of the water is then heated and reinjected in the subsurface. The excess water is treated before being discharged. The CROW process may be modified to treat any size area by varying the number of injection and recovery wells and adjusting the capacity of the water treatment system.
The CROW process technology was demonstrated at the Brodhead Creek Superfund site in Stroudsburg, Pennsylvania. This technology demonstration was a full-scale remediation effort lasting about 20 months. The CROW process system used for the SITE demonstration included six hot water injection wells, two recovery wells, an aboveground water treatment system, and a data acquisition and control system. The injection and recovery wells targeted an accumulation of free-phase coal tar within a 40-foot by 80-foot treatment area.
Primary demonstration objectives evaluated whether the CROW process removed coal tar from the subsurface or flushed the coal tar outside of the treatment area. The CROW process was successful in removing coal tar from the subsurface; however, it was unable to reduce coal tar concentrations to residual immobile levels. Measurements of the concentration of coal tar in the soil outside of the treatment area before and after the demonstration did not show a significant change. This suggests that the CROW process did not flush large amounts of contamination outside of the treatment area. Measurements of the amount of coal tar in the layer under the treatment zone before and after the demonstration suggest that some coal tar was pushed down into the underlying confining unit.
Potential sites for applying this technology include Superfund and other hazardous waste sites where the aquifer is contaminated by oily wastes. Economic data indicate that remediation costs of using this technology are affected by sitespecific factors. At the Brodhead Creek Superfund site, the cost for implementing a site cleanup using the CROW process was calculated at $85,000 per pore volume. As a comparison, the cost per pore volume at the Bell Lumber and Pole Company (Bell Pole) site in New Brighton, Minnesota was calculated at $61,900. The costs for the Bell Pole site are less due to better site conditions including less dissolved iron in the aquifer and a uniform sand aquifer. The cost per pore volume for implementing this technology at other sites is expected to fall within this range.