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Innovative Technology
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Tech ID: 237, 2238

Project Overview
 The purpose of this task is to enhance the applicability of the Ribbon NAPL Sampler (RNS), by FLUTe, to provide definitive detection of separate phase organics in the subsurface. The method, which is simple to use and broadly applicable, has been successfully deployed both above and below the water table and in open boreholes and through cone penetrometer rods. Successful deployments at Savannah River Site (SRS), Paducah GDP, and the McCormick-Baxter creosote site have established the utility of the RNS technology. To further enhance the utility of the technique, it is necessary to develop modes for addressing other common access methods. For example, other modalities that would enable greater applicability of the FLUTe method would include deployment in fractured rock systems (open boreholes) and deployment through the center of drill pipes.
Technology Description
 The Ribbon NAPL Sampler (RNS) is a continuous, direct sampling device that can provide detailed depth-discrete mapping of Non-Aqueous Phase Liquids (NAPLs) - liquid solvents and/or petroleum products in a borehole. This NAPL characterization technique uses a membrane system to deploy a hydrophobic absorbent ribbon in the subsurface. The system is pressurized against the wall of the borehole and the ribbon absorbs the NAPL that is in contact with it. A dye, sensitive only to NAPL, is impregnated in the ribbon and turns it bright red when the contaminants are contacted. Upon removal from the subsurface, the presence and depth discrete location of DNAPL is indicated by brilliant red marks on the ribbon. The RNS has been deployed using both direct push and drilled boreholes with diameters of 2" and larger in both the vadose and saturated zones. In FY 2000, a smaller diameter RNS was developed for deployment in 1.25" diameter boreholes, a common diameter of rods pushed by pneumatic hammer rigs such as the GeoprobeTM. The ability to definitively detect dense NAPL using direct push techniques is advantageous because the methods are generally faster and less expensive than conventional drilling, and Investigation-Derived Waste (IDW) is minimized. The original development of the RNS focused on deployment with the cone penetrometer in 2" diameter boreholes, but because there are far more GeoprobeTM rigs (approximately 1,000) used in environmental applications than cone penetrometer rigs (less than one hundred), the benefit of a smaller diameter RNS is obvious. In addition to the smaller diameter RNS, an RNS has been fabricated for deployment in a fractured rock borehole, and will also deploy the RNS through sonic drill casing. The main thrust of work this year has been to expand the capabilities of the RNS for greater applicability at both public and private contaminated sites.

All of the Dense Non-Aqueous Phase Liquid (DNAPL) research and development projects at the Savannah River Site (SRS) are selected based on targets driven by site cleanup goals and local and regional regulatory requirements. The RNS is part of a coordinated package of innovative DNAPL characterization tools that have been developed and deployed. Each technology was carefully designed to:

  • Unambiguously identify DNAPLs in the subsurface.
  • Minimize secondary waste.
  • Eliminate undesirable gravitational movement of DNAPLs.
  • Minimize IDW.
  • Mitigate similar types of collateral environmental damage inherent in addressing this complex environmental need.

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