hazardous substances at moffett field’s hangar one: challenges and opportunities

Hazardous Substances atMoffett Field’s Hangar One:

Challenges and Opportunities

Moffett Field added to “Superfund” List in1987 because of TCE Contamination

In 2003 Hangar One found to be

source of PCBs in Moffett wetlands

Navy’s proposal to demolishhangar blocked by public outcry

So Navy removed siding/roofand coated the frame

Long-Term Management Planrequires inspections of coating on

• Structural steel frame (excluding the top and bottomsides of the mezzanine deck).

• Concrete Masonry Unit (CMU) walls surrounding thesix electrical vaults.

• CMU walls surrounding the former hazardousmaterials storage room.

• CMU walls that were part of the former toilets.

• Door operating mechanisms (trucks/bolsters, motorhousing, electrical vaults, and drive gear housing).

and sampling of stormwaterand sediment

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

Reuse will require mitigationof vapor intrusion

Aerated floor can be installed with newconcrete slab to prevent vapor intrusion

Existing tunnel and any newutility corridors must be sealed

and air monitoring will benecessary after re-covering

The Navy is responsible forinspection and maintenance ofHangar One’s epoxy coating as wellas stormwater and sedimentsampling.

The Navy is also responsible forvapor mitigation in existing buildings.

But it doesn’t want to be.

Any lessee who attaches a newroof/siding and/or modifies thehangar floor is likely to incurSuperfund liability.

SOLUTION: Navy pays lessee to takeresponsibility for long-termmanagement of residualcontamination as well as vapormitigation, based upon Navy’sprojected costs.

Navy can’t just walk away.

Negotiations among lessee, NASA,Navy, and EPA are essential.