U.S. Environmental Protection Agency
Legislative Hearing on Use of Dispersants in BP Oil Spill
Senate Committee on Appropriations:
Subcommittee on Commerce, Justice, Science, and Related Agencies
Chairman Mikulski, Ranking Member Shelby
EPA’s Oil Spill Program focuses on activities to prevent, prepare for and respond to oil spills from a wide variety of facilities that handle, store, or use various types of oil. The National Contingency Plan (NCP) is the federal government's blueprint for responding to both oil spills and hazardous substance releases. Under the NCP, the EPA or the USCG provide federal On-Scene Coordinators (FOSCs) for the inland and coastal zones, respectively, to direct or oversee responses to oil spills. The NCP established the National Response Team (NRT), comprised of fifteen federal agencies, to assist responders by formulating policies, providing information, technical advice, and access to resources and equipment for preparedness and response to oil spills and hazardous substance releases. EPA serves as chair of the NRT and the USCG serves as vice-chair.
EPA is collecting samples along the shoreline and beyond for chemicals related to oil and dispersants in the air, water and sediment, supporting and advising USCG efforts to clean the reclaimed oil and waste from the shoreline, and closely monitoring the effects of dispersants in the subsurface environment. The USCG, in consultation with EPA and the states, approved waste management plans outlining how recovered oil and waste generated as a result of the BP oil spill will be managed.
Use of Dispersants: Following the April 20, 2010 Deepwater Horizon mobile offshore drilling unit explosion and resulting oil spill, the USCG, in consultation with EPA, DOI, NOAA, and the State of Louisiana, granted BP authorization to use approved dispersant on oil on the surface of the water in an effort to mitigate the shoreline impacts of the oil on fisheries, nurseries, wetlands and other sensitive environments.
There are environmental tradeoffs and uncertainties associated with the widespread use of large quantities of dispersants. We know dispersants are generally less toxic than the oils they break down. We know that surface use of dispersants decreases the environmental risks to shorelines and organisms at the surface and when used this way, dispersants break down over several days to weeks. In addition, the use of dispersants at the source of the leak represents a novel approach to addressing the significant environmental threat posed by the spill.
Results to date indicate that subsea use of the dispersant is effective at reducing the amount of oil reaching the surface, and can do so by using less dispersant than is needed to disperse oil after it reaches the surface, and has resulted in significant reductions in the overall quantity of dispersants being used to minimize impacts in the deepsea.
EPA has also established an extensive network to rigorously monitor the air, water, and sediments for the presence of dispersants and crude oil components that could have an impact on health or the environment. All monitoring information and data are posted on EPA’s website. In addition, for subsea monitoring, the toxicity data generated from this monitoring to date does not indicate significant effects on aquatic life. We are closely watching the dissolved oxygen levels, which so far remain in the normal range. Moreover, decreased size of the oil droplets is a good indication that, so far, the dispersant is effective.
EPA required toxicity tests to standard test species, including a sensitive species of Gulf of Mexico invertebrate (mysid shrimp) and fish (silverside) which are common species in Gulf of Mexico estuarine habitats. The invertebrate and fish species tested are considered to be representative of the sensitivity of many species in the Gulf of Mexico, based on years of toxicity testing with other substances. Initial peer reviewed results from the first round of EPA’s toxicity testing indicated that none of the eight dispersants tested, including the product currently in use in the Gulf, COREXIT 9500 A, displayed biologically significant endocrine disrupting activity. The results are posted on our website. While we await the final round of scientific testing, it appears that all the products that are currently registered have roughly the same impact on aquatic life.
For more information on EPA’s efforts in the gulf and for the latest air, water, sediment and underwater dispersant monitoring data.