EPA Vapor Intrusion Update

Former NAS Moffett FieldRestoration Advisory Board Meeting

May 10, 2012

Alana Lee

EPA Region 9

Lee.Alana@epa.gov

Vapor Intrusion Study Area – Moffett Field Area and MEW Area

Estimated Extent of Regional TCE Shallow GroundwaterPlume

Vapor IntrusionStudy Area –

Moffett Field Area

4

Sampling Status of “Unsampled” Buildings -Moffett Field Area - North of Highway 101

23 569

48 583A

146 583B

154 583C

503 596

543 944

554

5

6 Currently OccupiedBuildings Sampled by NASA– Nov 2011

13 Currently Occupied BuildingsSampled by MEW

N144

N212

N213

N240

N245

T20G

MEW Building –Specific Indoor Air Sampling Reports – Sept 13, 2011

Vapor IntrusionStudy Area –

Navy & NASABuildings

6

Sampling Status of Navy Buildings

7

22 Buildings to Be Sampled by Navy – May 2012

Navy Indoor Air Sampling Work Plan for Vapor Intrusion – May 2012

2 45 567

3 67 N210

10* 76 N239

12 107 N239A

13 126 N243

14 510 N243A

16 555

29 566

Building 10 Tunnel and Manhole Locations

8

EPA TCE Regional Screening Levels and MEW/Moffett FieldSite-specific Cleanup Levels for Chronic Exposure

EPA Regional Screening Level(RSL) – December 2011

MEW/Moffett FieldCleanup Levels

AIR(mg/m3)

Cancer(1x 10-6)

Non-cancer

INDOOR AIR(mg/m3)

Residential(24-hr)

0.4 2 1

Commercial(8-hr)

3 9 ------

Commercial(10-hr)

2 7 5

TAP WATER (mg/L) GROUNDWATER

Residential 0.4 mg/L 3 mg/L 5 mg/L(MCL)

9

For More Information - Websites

NASA:

environment.arc.nasa.gov/reports/vapor.htmlenvironment.arc.nasa.gov/maps/vapor.html

EPA:

www.epa.gov/region9/moffettfield

www.epa.gov/region9/mew

www.epa.gov/oswer/vaporintrusion/

For more information on TCE: http:/www.epa.gov/IRIS

and click on TCE link