1.
Hazardous Substances at
Moffett Field’s Hangar One:
Challenges and Opportunities

2.
Moffett Field added to “Superfund” List in
1987 because of TCE Contamination

3.
In 2003 Hangar One found to be
source of PCBs in Moffett wetlands

4.
Navy’s proposal to demolish
hangar blocked by public outcry

5.
So Navy removed siding/roof
and coated the frame

6.
Long-Term Management Plan
requires inspections of coating on
• Structural steel frame (excluding the top and bottom
sides of the mezzanine deck).
• Concrete Masonry Unit (CMU) walls surrounding the
six electrical vaults.
• CMU walls surrounding the former hazardous
materials storage room.
• CMU walls that were part of the former toilets.
• Door operating mechanisms (trucks/bolsters, motor
housing, electrical vaults, and drive gear housing).

7.
and sampling of stormwater
and sediment

8.
EPA leading effort to replace pump-and-
treat with new groundwater remedies

9.
Reuse will require mitigation
of vapor intrusion

10.
Aerated floor can be installed with new
concrete slab to prevent vapor intrusion

11.
Existing tunnel and any new
utility corridors must be sealed

12.
and air monitoring will be
necessary after re-covering

13.
The Navy is responsible for
inspection and maintenance of
Hangar One’s epoxy coating as well
as stormwater and sediment
sampling.
The Navy is also responsible for
vapor mitigation in existing buildings.
But it doesn’t want to be.

14.
Any lessee who attaches a new
roof/siding and/or modifies the
hangar floor is likely to incur
Superfund liability.

15.
SOLUTION: Navy pays lessee to take
responsibility for long-term
management of residual
contamination as well as vapor
mitigation, based upon Navy’s
projected costs.
Navy can’t just walk away.
Negotiations among lessee, NASA,
Navy, and EPA are essential.