Former NAS Moffett Field
Status of Site 25
Restoration Advisory Board Meeting
September 10, 2009

Presentation Overview
Site 25 refresher
• Location
• Contamination
• Risks
• Remedial action objective
Current status and path forward
2

Site 25 Location & Description
• Located in the northwestern
corner of NAS Moffett Field
• Stormwater system managed by
NASA (except for Stevens Creek
Shoreline Nature Study Area)
• Stormwater flows through NASA
settling basin to Eastern Diked
Marsh and into the stormwater
retention ponds
3

Site 25 Contamination
Sediment contains lead, zinc, polychlorinated biphenyls (PCBs), and
DDT (dichlorodiphenyltrichloroethane)
Contamination likely from discharge of stormwater to Site 25 and
application of DDT
Potential upland source areas are being addressed separately
4

Site 25 Risks
Risks to human health are acceptable
• Risk will be further reduced by remedial action to address
ecological risk
Risk to site wildlife is driving remedial action
• Remedial action based on tidal marsh scenario (most
sensitive habitat)
• Lead, zinc, DDT, and PCBs pose unacceptable risk to
invertebrates, birds, and mammals
5

Remedial Action Objective
Reduce exposure to concentrations of lead, zinc, DDT, and PCBs
in sediment at Site 25 to levels that are protective of ecological
receptors if the site contains a tidal marsh in the future
6

Selected Remedy
Focused Treatment
• Treat sediment contaminated with only lead and zinc
• Stabilize lead and zinc so soil can be disposed of as non-
hazardous waste
Excavate sediment and dispose off site
Restoration - backfill wetland habitat, as needed, and re-vegetate with
native plants
Ecological Monitoring - of the wetland areas during the construction to
evaluate recovery
7

Selected Remedy
8

Site 25 Current Schedule
Proposed Plan
• Submitted January 9, 2009
• Public Meeting on January 22, 2009
Record of Decision
• Draft ROD out on April 30, 2009
• All comments back on July 29, 2009
Draft final ROD due out on September 29, 2009
• Final ROD October 29, 2009
Note – ROD includes Responsiveness Summary
9

Site 25 Path Forward
Finalize Record of Decision - October 29, 2009
Begin Remedial Design – Mid 2010
• Currently working through contract award
• Request funds at the beginning of FY 2010
Remedial Action – Early 2011
10

Questions?
11