Risk Assessment of the Potential Release of PCBs and Other Contaminants from Sunken Navy Ships (SINKEX) in the Deep Ocean

	SINKEX risk assessment conceptual model.

Prior to 1989, the Navy’s deep-water sinking exercise (SINKEX) program intentionally, and sometimes inadvertently, sank target vessels - former U.S. Navy warships - during live fire training and weapons testing exercises. Most SINKEXs took place in ocean waters greater than 3,000 m (6,000 ft) in depth, although some ships inadvertently sank in depths of 600-1000 m (1,800-3,000 ft). In 1989 the Navy voluntarily suspended the SINKEX program and discontinued the donation of ships for reef building (REEFEX) when it was discovered that PCBs in solid materials (PCBs-ISM) were likely to be found aboard the ships being used for these programs. The solid materials containing PCBs included electrical cable insulation, rubber products, felt gaskets, bulkhead insulation, paints, and other similar materials.

An initial evaluation of the problem, based on limited laboratory data, existing literature, and a numerical model of PCB releases in the deep ocean, concluded that PCBs left onboard target ships did not pose an adverse risk to the marine environment. However, the U.S. Environmental Protection Agency (EPA) noted that the report contained no field data and did not consider the release of potentially toxic substances other than PCBs. The EPA stipulated that field data documenting acceptable risk from sunken SINKEX ships would be needed for the EPA to concur with continuation of the Navy’s SINKEX program. In 1995, SSC San Diego, in cooperation with the EPA Office of Water, developed a plan to evaluate the marine environment in the vicinity of a sunken U.S. Navy ship to determine whether potentially toxic materials from that ship (particularly PCBs) were being released, and whether any releases might pose an adverse risk to the environment. A PCB leach rate study and a field study of the environmental effects from sunken Navy vessels at SINKEX sites was proposed by the Navy, reviewed by the EPA, and approved in an agreement signed by the EPA and the Navy in 1996.

Capabilities:

• Environmental compliance and analytical chemistry

Applications:

• Empirical source data input to environmental modeling and risk assessments

More Information:

• George, R.D., C.R. In, R.K. Johnston, C.A. Kurtz, P.F. Seligman, R.D. Gauthier, and W.J. Wild. 2006. Investigation of PCB Release-Rates from Selected Shipboard Solid Materials Under Laboratory-Simulated Shallow Ocean (Artificial Reef) Environments. Technical Report 1936. SSC San Diego, CA. 230 pp. [9.34 MB PDF file]
• George, R.D., C.R. In, R.K, Johnston, C.A. Kurtz, P.F. Seligman, R.D. Gauthier, and W.J. Wild. 2006. Investigation of PCB Release-Rates from Selected Shipboard Solid Materials Under Laboratory-Simulated Shallow Ocean (Artificial Reef) Environments. Final Report with Appendices, January 2006. Prepared for Program Executive Office Ships (PMS333) Naval Sea Systems Command. Space and Naval Warfare Systems Center, San Diego, CA. 1073 pp.
• George, R.D., C.R. In, R.K. Johnston, P.F. Seligman, R.D. Gauthier, and W.J. Wild. 2005. Seawater Leaching Investigation of Polychlorinated Biphenyls from Solid Matrices. Proceedings of Oceans 2005, IEEE and MTS, September 18-23, 2005, Washington, D.C. 9 pp.
• In, C.R., J.M. Guerrero, K.M. Lane, and R.D. George. 2001. Controlled Leaching Studies of Chlorinated Biphenyls from Solid Matrices into Seawater. ACS Environmental Preprints 41(1): 262.
• In, C.R., J.M. Guerrero, K.M. Lane, and R.D. George. 2001. Screening-Level Determination of Chlorinated Biphenyls in Seawater Matrices using Enzyme-Linked Immunosorbent Assay (ELISA) Techniques. ACS Environmental Preprints 41(1):174.
• Johnston, R.K., R. George, K.E. Richter, P.F. Wang, and W.J. Wild. 2006. EX-ORISKANY Artificial Reef Project: Ecological Risk Assessment. Final Report January 22, 2006. Prepared for Program Executive Office Ships (PMS333) Naval Sea Systems Command. Space and Naval Warfare Systems Center, San Diego, CA. 268 pp.
• Johnston, R.K., H. Halkola, W., Wild, R., Gauthier, R., George, C., In, M., Bell, and R. Martore. 2003. Assessing the Ecological Risk of Creating Artificial Reefs from ex-Warships. Proceedings of Oceans 2003. 8 pp.