Tri-Service Site Characterization and Analysis Penetrometer System (SCAPS) Membrane Interface Probe

Several demonstrations of the ion trap mass spectrometer-Membrane Interface Probe ITMS-MIP system for volatile organic compounds VOCs were completed between August of 1998 and May of 2000. The purpose of each demonstration was to show the ability of the ITMS-MIP vapor sampling system to characterize the extent of subsurface contamination during a single field deployment. Previous Site Characterization and Analysis Penetrometer System SCAPS ITMS-MIP field investigations include a demonstration at Alameda Naval Air Station NAS, Alameda, CA, completed in August 1998 Long Horn Army Ammunition Plant, Karnack, TX, in September 1998 and Lake City Army Ammunition Plant, Independence, MO, in March 1999. Validation demonstrations for the SCAPS ITMS-MIP system took place at the NAS North Island, Coronado, CA, in July 1999 and April-May 2000 and at the Department of Energy Savannah River Site, Aiken, SC, August-September 1999. Results of the demonstration at the Savannah River Site are discussed briefly however, the major emphasis of this report is the demonstration at NAS North Island in April-May 2000, which was specifically carried out as a production deployment. The ITMS-MIP system uses the commercially available MIP to collect vapor samples from the subsurface. The MIP collects VOC samples from the subsurface through a permeable membrane into a helium carrier gas that transports the sample above the ground surface for analysis. The analysis is performed in real-time by a direct sampling ITMS in accordance with U.S. Environmental Protection Agency USEPA draft Method 8265 USEPA 1994. Approximately 4 minutes elapse from the time the MIP reaches the sample depth of interest until the analysis results are available. The production deployment at NAS North Island in April-May 2000 yielded 493 depth-discrete samples collected and analyzed from 28 different investigation locations.