1. WelcomePetroleum Site 14 UpdateFormer Naval Air Station Moffett Field M ffFi ldWilson Doctor - Navy Project Manager3/10/11 RAB meeting

2. Presentation Overview Site 14 background Recent Site 14 activities Site characteristics Upcoming cleanup activities Site strategy 3. Site 14 Background Former Department of Defense motor vehicle gasoline station Two former 5,000 gallon underground storage tanks (USTs)removed in 1986 Stored unleaded gasoline and diesel fuel 1986 to 2006: Navy conducted soil sampling groundwater sampling,sampling, and treatability studies3 4. Recent Site 14 Activities 2008 to present: Additional sampling to characterize site March 2010: Discovered uncharacterized area of petroleumconstituents in groundwater June 2010: Conducted groundwater sampling Petroleum constituents related to Site 14 Based on findings, low pressure air sparge treatment system designwas modified to treat this area January 31 to March 18, 2011: Install treatment system 4 5. Site CharacteristicsExtent of TPH-GExtent of BenzeneConcentrations Concentrations inin Groundwater Groundwater 5 6. Air Sparging) Inject air into the ground using air spargewells and an air compressor Injected air increases oxygen levels andpromotes biodegradation of petroleumconstituents in groundwater Sparge wells will inject air into sandy water-bearing layer between 18 and 23 ft bgs toachieve treatment The system is expected to operate for oneyear followed by a monitoring period6 7. Well Locations 7 8. Site Strategy Biosparging System Operation System S t Operation/System Optimization no Rebound yes Within AcceptableLimits?no noAsymptotic Remediationyes Shut Biosparging SystemConditionsDown and EvaluateGoals Achieved? Realized? Contaminant Reboundyesyes Implement MNA to Cleanup Goals Site Closure Achieve Cleanup GoalsAchieved? noMonitored Natural Attenuation8 9. 9 10. 10 11. 11 12. Thank You12