site 25 rab nov 29 2012
TRANSCRIPT
Former NAS Moffett Field
Site 25 Remedial Action Update
Bryce Bartelma, PG
Salient Federal Solutions
supporting
Navy BRAC PMO West
November 29, 2012
RAB Meeting
IR Site 25
IR Site 25 encompasses approximately 230 acres and was constructed for useas part of the Moffett Field storm water management system since 1953
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The Navy is coordinating remedial action activities with NASA as theyprepare to conduct their cleanup activities at Area of Investigation (AOI)-14
AOI-14
Remedial Design andRemedial Action Work Plan
• Final Remedial Designand Remedial ActionWork Plan (RD/RAWP)distributed on March 30
• Removal of over 32,500cubic yards of sedimentfrom nearly 32 acres
• Planned excavationdepths of 0.5 – 1.5 feetbelow ground surface
• Restore vegetatedareas with pickleweedand other native grass
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Temporarily Re-routeStorm Water & WATS effluent
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Catch Basin
Storm WaterSettling Vault
August 2012 Conditions at IR Site 25
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Biological Observations at Site 25
NESTING
• Alameda Song Sparrow
• Western Harrier
• Mockingbird, marsh wren, bushtit andkilldeer
OBSERVED
• Harvest Mice (unidentified subspecies)
• Deer Mice & Voles
• California Least Tern (in flight)
• Black Rail (vocalizing)
• Fox, jackrabbit, and gopher snake
NOT OBSERVED
• Western Pond Turtle (WPT)
• Western Snowy Plover
• California Clapper Rail 6
Biological Protection Measures
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PROTECTION MEASURES
1. Visually inspect/clear vegetationprior to removal
2. Hand remove pickleweed
3. Silt fencing along access pointsand suitable habitat areas
4. Continuous biologicalmonitoring
5. Coordination with CDFG andUSFWS
Sediment Excavations
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• Planned excavation depths of 0.5 – 1.5feet below ground surface
• Field surveying to verify dig depths
• Grid confirmation sampling
Over-excavations
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• Several samples confirmed additionalover-excavation was required
• Primarily in Eastern Diked Marsh (EDM)
• Depths of up to 5 feet below groundsurface (EDM) encountered groundwater
IR Site 25 Remedial Action Facts
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• Excavation depths of 0.5 to 5.0feet below ground surface
• 36,390 cubic yards of sedimentfrom nearly 32 acres
• 19,500 linear feet of biological siltfencing
• Utilized up to 14 biologists
• Bypassed 15,724,800 gallons ofWATS and storm water
• 236 confirmation samples
• 173 days with up to 40 workers(over 23,502 hours) on site
• 2,173 truck loads of sedimenttransported to landfill
Aerial Imagery
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Aerial Imagery
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Vegetation Restoration
Pickleweed
Salicornia
virginica
Saltgrass
Distichlis
spicata
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• All vegetation areas removedduring Remedial Action will berestored (excludes EDM andinundated mud flats)
• Two types of hydroseed palettes(High Salt Marsh and TransitionalUpland) will be used withmajority of seeds includingpickleweed and saltgrass
• Minimum of two years monitoringand maintenance
• Options for irrigation services andadditional hydroseeding/plantings
Schedule
• Sediment Excavations andDisposal
Completed
• Vegetation Restoration
Nov./Dec. 2012
• Vegetation Monitoring
Ongoing
• Submit Remedial ActionCompletion Report
Spring 2013
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Questions?
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Point of Contact:
Scott Anderson
BRAC Environmental Coordinator
(619) 532-0938