Demonstration Of Close Coupled Barriers For Subsurface Containment Of Buried Waste Conceptual Test Plan PDF Download

Between 1952 and 1970, DOE buried mixed waste in pits and trenches that now have special cleanup needs. The disposal practices used decades ago left these landfills and other trenches, pits, and disposal sites filled with three million cubic meters of buried waste. This waste is becoming harmful to human safety and health. Today's cleanup and waste removal is time-consuming and expensive with some sites scheduled to complete cleanup by 2006 or later. An interim solution to the DOE buried waste problem is to encapsulate and hydraulically isolate the waste with a geomembrane barrier and monitor the performance of the barrier over its 50-yr lifetime. The installed containment barriers would isolate the buried waste and protect groundwater from pollutants until final remediations are completed. The DOE has awarded a contract to RAHCO International, Inc.; of Spokane, Washington; to design, develop, and test a novel subsurface barrier installation system, referred to as a Subsurface Containment System (SCS). The installed containment barrier consists of commercially available geomembrane materials that isolates the underground waste, similar to the way a swimming pools hold water, without disrupting hazardous material that was buried decades ago. The barrier protects soil and groundwater from contamination and effectively meets environmental cleanup standards while reducing risks, schedules, and costs. Constructing the subsurface containment barrier uses a combination of conventional and specialized equipment and a unique continuous construction process. This innovative equipment and construction method can construct a 1000-ft-long X 34-ft-wide X 30-ft-deep barrier at construction rates to 12 Wday (8 hr/day operation). Life cycle costs including RCRA cover and long-term monitoring range from approximately $380 to $590/cu yd of waste contained or $100 to $160/sq ft of placed barrier based upon the subsurface geology surrounding the waste. Project objectives for Phase I were to validate the SCS construction equipment and process, evaluate the system performance, validate the barrier constructability, and assess the barrier effectiveness. The objectives for Phase 11, which is a full-scale demonstration at a DOE site, are to perform an extensive characterization of the test site, to demonstrate the equipment and the installation process under site-specific performance and regulatory requirements, to validate the operational performance of the equipment, and to perform long-term verification of the barrier using monitoring wells. To date, significant progress has been made to establish the technical and economical feasibility of the SCS. This report describes the SCS conventional and specialized equipment, barrier materials, and construction process. It presents results of the specialized equipment Factory Test, the SCS Control Test and the SCS Advance Control Test at the RAHCO facility. Provided herein are the system performance capabilities and an estimated construction cost and schedule for a 1000-ft-long X 34-ft-wide X 29-ft-deep containment barrier at the DOE Oak Ridge Bear Creek Burial Grounds are also provided.