Groundwater Update and Remedial Optimization Process Overview
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The document discusses the ongoing groundwater cleanup at the NASA Moffett Field site, which has contamination from volatile organic compounds like trichloroethene. It provides background on the site, outlines recommendations from a 2004 EPA review to optimize the groundwater remedy, and discusses next steps like implementing approved recommendations and conducting a second five-year review in 2009. Optimization efforts include improving effectiveness, efficiency, and cost effectiveness of the groundwater treatment systems while maintaining or improving cleanup progress and protecting human health.
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Groundwater Update and Remedial Optimization Process Overview
- 1. Groundwater Update and Remedial Optimization Process Overview NAS Moffett Field Restoration Advisory Board Meeting January 8, 2009 Alana Lee EPA Region 9
- 4. MEW / NAS Moffett Field Site – Shallow TCE Plume Fairchild Intel Raytheon NEC SMI Vishay/ Sumco NASA Navy
- 5. MEW / NAS Moffett Field Site Background • Shallow A, A2/B1, B2, B3, C and deeper groundwater zones – contaminated with volatile organic compounds (VOCs), primarily trichloroethene (TCE) • EPA Record of Decision - 1989 • EPA Oversight – MEW Admin Order - 1990, Consent Decree - 1992, Navy FFA Amendment - 1993 • Soil cleaned up (excavation and/or soil vapor extraction) • Groundwater cleanup continues using pump and treat systems (carbon, air strippers, slurry walls). • Current TCE in shallow groundwater up to 40,000 ppb inside slurry walls and generally 100 to 10,000 ppb outside the slurrywalls • Groundwater cleanup level is 5 ppb for TCE.
- 6. Soil removal and Cleanup
- 7. Fairchild and Raytheon Slurry Walls FAIRCHILD BLDGS. 1-4 FAIRCHILD BLDG. 9 RAYTHEON FAIRCHILD BLDG. 19 Four underground containment walls to isolate chemicals
- 8. TCE Groundwater Plume and Monitoring Wells
- 9. Groundwater cleanup is ongoing
- 10. A-Zone TCE Plume 2005 1998 2001 2002 2004 1987 2003 1992 2000
- 11. Cleanup Progress Moffett The plume has NASA been stabilized. Field Interim remedial Groundwater cleanup measures NAVY concentrations began in 1982. have been reduced by more than 75%. MEW Ten groundwater treatment PRPs have systems have spent more than treated over 2.8 $140 M on billion gallons of GTE cleanup water and more activities. than 75,000 pounds of VOCs. Soil cleaned up. More than 36,000 cubic yards of soil excavated. Five soil vapor extraction systems operated.
- 12. VOC Mass Removed (through 2005) Cumulative Cumulative Groundwater VOC Company Extracted & Treated Mass Removed (gallons) (pounds) Fairchild - 1 524,000,000 14,300 Fairchild - 3 437,000,000 20,850 Fairchild - 19 887,000,000 10,300 Intel 78,000,000 2,000 NEC 19,000,000 27 Raytheon 282,000,000 12,900 SMI 56,000,000 43 Vishay 12,000,000 319 RGRP S101 312,000,000 6,500 NASA 7,000,000 25 Navy 232,000,000 3,200 RGRP N101 549,000,000 6,500 Total 3,395,000,000 76,964
- 13. Superfund Redevelopment Redevelopment to high profile commercial campus began in late 1990s and continues today.
- 14. Modifications to Treatment Systems Carbon Carbon Carbon Carbon X Oxidation Carbon & Oxidation Air Stripping Carbon Carbon In response to community concerns, air strippers replaced with other systems
- 15. 2004 EPA Five-Year Review – Groundwater Recommendations and Follow-up Actions • Develop and implement optimization plan to improve the effectiveness of the groundwater remedy at each facility and the Regional Program • Include additional wells in sampling network to further assess contamination • Evaluate extraction well network and pumping rates to improve capture and maintain desired gradients • Install new extraction wells to enhance mass removal and plume capture • Evaluate applicability of other cleanup technologies to expedite mass removal and cleanup time
- 16. Groundwater Remedy Optimization Optimization efforts include: • Improving the effectiveness of the remedy in protecting human health and the environment • Improving efficiency • Improving cost effectiveness while maintaining the same or higher level of effectiveness • Expediting progress towards site cleanup and closure
- 17. Some Optimization Recommendations Optimization recommendations included: • Modification to extraction rates • Further evaluation of alternate technologies • Re-location/replacement of extraction wells • Conduct treatability/pilot studies of alternative technologies
- 18. Next Steps • Consider public input • EPA Review Comments on Optimization reports • Implement approved optimization recommendations in a timely manner • Optimization efforts included in Annual Reports • EPA Second Five-Year Review - 2009
- 19. Questions?