Area I Burn Pit Santa Susana Field Laboratory RCRA Facility Investigation Work Plan

1. Area I Burn PitSanta Susana Field LaboratoryRCRA Facility Investigation Work Plan February 19, 2008 Laura Rainey, P.G. Senior Engineering Geologist California Environmental Protection Agency Department of Toxic Substances Control

2. Today’s Discussion • Discuss status and scope of DTSC’s review • Review questions previously raised regarding Area I Burn Pit investigation • Describe additional work proposed to complete the Burn Pit’s RFI 2

3. RFI objectives • Identify sources of chemical contamination, what chemicals are involved, and the extent of their occurrence • Evaluate where chemical contaminants are, where they go, and how they get there • Gather data needed to make decisions on interim or final cleanup measures • Obtain sufficient info to complete a risk assessment 3

4. Scope of Review: RFI Work Plan • Site History and Chemical Use • Site Conditions • Nature and Extent of Chemical Impacts – review data for all media (soil, sediment, soil vapor, surface water, groundwater) • Screening for radioactive waste 4

5. Previous Questions • What is the Area I Burn Pit? • Do we have adequate historical documentation that describes past Burn Pit activities? • What was burned or disposed of there? • What chemicals are left behind? • Was radioactive waste burned or disposed of there? • Are we looking at all relevant pathways for potential contaminant migration? 5

6. What was the Area I Burn Pit? • Established 1958 through 1971. Discontinued in 1971 due to “air pollution considerations”. Operated intermittently from 1971 through 1990. • Used for burning, dilution, destruction of various materials. • Six acres, six pits ranging in volume from 200 to 10,000 gallons. • Burn Pit also had burial/disturbed areas, drum & equipment storage areas, above ground storage tanks and other structures. 6

7. Site Location Map 7

8. Burn Pits 1961 8

9. Burn Pit Modifications 1963 9

10. Historical Soil Sampling Locations 10

11. Proposed Sampling Locations 11

12. Historical Documentation • Boeing was required to provide certified compilation of relevant historical documents. • These documents are included in Appendix C of the Work Plan • These documents include: • Inventory logs, records, and available invoices; • Operations files • Site/facility investigation files • Regulatory compliance correspondence, audits, permits, monitoring reports, sampling reports, etc. • Deposition testimonies from former workers 12

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17. What was Burned or Disposed of at the Burn Pit? • Wastes included: • 450,000 gallons of fuels • 6,924 igniters • 21,300 gallons of process chemicals • 13,810 pounds of reactive metals • 31,717 gallons of organic solvents • 5,121 pounds of explosives • 32,932 cubic feet of toxic gases • 191 gallons of heavy metal toxics 17

18. Sources of Waste Materials • On-site sources (site-wide, including Area IV) • Off-Site sources (i.e., Canoga, Vanowen, Desoto & Science Center) 18

19. What Chemicals Were Left Behind? • Chemicals identified during previous investigations: • 1981-1982 Geophysical surveying, remedial excavations, soil sampling & analysis • 1990 soil sampling and analysis • 1993 removal of structures, geophysical surveying, metallic-anomaly excavations, soil sampling & analysis • 1994 soil sampling & analysis • 2003 soil leachate & suface water sampling & analysis • 2005 soil sampling & analysis • 2006 soil sampling 19

20. What Chemicals Were Left Behind? • Need to consider initial materials that were burned, destroyed, or diluted in order to evaluate potential by-products • Example – waste burned will potentially result in residual thermal decomposition (i.e., burned) products • Table 2-1 (in QAPP, Appendix A) lists potential analytical parameters & their potential thermal decomposition products and associated analytical methods • Table 2-2 lists potential analytical parameters & analytical methods that will be used to determine the presence of original waste materials 20

21. Examples – What Chemicals Were Left Behind? From Table 2-1: • For acids, screen for total anions (chloride, fluoride, sulfate, nitrate, nitrite, phosphate), pH using USEPA Method 300.0, EPA Method 150.2 • For perchlorate-containing propellants, screen for perchlorate using USEPA Method 314.0 21

22. Was Radioactive Waste Burned or Disposed of at Burn Pit? • Based on review to date, no definitive information suggests it has, but questions remain… • Examples: cesium from Canoga & Desoto (7 pounds in early 1960’s) • Na, K, NaK, and Li from Area IV sites • Materials from radiological buildings in Area IV (i.e., 4003, 4009, 4023, 4020) • Materials from non-radiological buildings in Area IV (i.e., 4057, 4065) 22

23. Are We Looking At Relevant Pathways for Contaminant Migration? Yes. Work Plan addresses the following potential pathways: • Air dispersion migration from past burning activities • Groundwater migration • Surface water and sediment migration • Soil Vapor migration 23

24. How do we deal with the uncertainties? • Utilize geophysical surveys • Utilize radiological materials screening survey • Conduct air dispersion modeling with field validation sampling • Conduct additional sampling and analyses 24

25. Proposed Work for Addressing Deficiencies • Utilizes relevant historical information to better describe & delineate former chemical use areas • Conduct air dispersion modeling w/field validation sampling to evaluate potential pathway of airborne particulates from past burning activities • Will conduct additional multi-media sampling to complete characterization and determine site-related chemicals of concern • Conduct radiological materials screening survey to address uncertainties 25