IR Site 25 UpdateIR Site 25 UpdateJuly 14, 2011 July 14, 2011 y ,y ,

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Presenter: Bryce Bartelma, Navy Project Manager

IR Site 25IR Site 25

IR Site 25 encompasses approximately 230 acres and was constructed for use as part of the Moffett Field storm water management system since 1953

AOI-14

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The Navy is coordinating remedial action activities with NASA as they prepare to conduct their cleanup activities at Area of Investigation (AOI)-14

Remedial Design andRemedial Design andRemedial Action Work PlanRemedial Action Work Plan

• Draft Remedial Design and Remedial Action Work Plan (RD/RAWP) distributed on March 30

• Revised Draft RD/RAWP distributed on May 10 (added details for potential dewatering and water diversion)

• Currently working on Response to Comments (RTCs) and the Draft-Final RD/RAWP

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Current Conditions at IR Site 25Current Conditions at IR Site 25

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Potential DewateringPotential Dewatering

• Pump up to 90,000,000 gallons of brackish water from IR Site 25 to Alviso Pond A2EPond A2E

• Two (2) pumps at up to 3,500 gallons per minute• Sand filters to remove any potential contaminated sediment• Daily compliance sampling for contaminants of ecological concern• Daily compliance sampling for contaminants of ecological concern

Alviso A2E Pond

IR Site 25

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Baseline Sample CollectionBaseline Sample Collection

• Four (4) surface water samples to compare baseline concentrations in Site 25 and Alviso A2E pond

• Comparable chemical results with similar salinity and total dissolved solids

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Potential Interior Management of WaterPotential Interior Management of Water

• Cofferdam to isolate polygons requiring remediation

• Reduced overall capacity of ponds will likely require pumping water back and forth

• Increased cost

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Biological ConsiderationsBiological Considerations

• Salt Marsh Harvest Mouse– Visually inspect/clearVisually inspect/clear

vegetation prior to removal– Hand remove pickleweed– Silt fence along equipment g q p

access points• Protected Birds

– Completed nesting surveys (no protected species observed)

– Continuously conduct inspections for sightingsinspections for sightings

• Western Pond Turtle– State species of concern

Presence not likely but part of– Presence not likely but part of resource education program

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Questions?Questions?

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