Abstract:

The use of dispersants began shortly after the Deepwater Horizon (DWH) accident occurred in April of 2010, and ended shortly after the Mississippi Canyon lease block 252 (MC-252) well was capped in July 2010. The U.S. Coast Guard Federal On-Scene Coordinator (FOSC) and U.S. Environmental Protection Agency (EPA) authorized their use to disperse oil that could not be removed by other methods, with the goal of reducing the amount of oil in areas where persons were working onsite to cap and contain the well, and reducing the amount of oil that reached nearshore and shoreline habitats. Dispersants were applied to oil slicks located on the water surface at least 3 nautical miles (nmi) or more from the shoreline. EPA, BP, and others collected samples of water and air around the areas where dispersants were used, and along the Gulf shoreline, to determine whether any person or marine life was exposed to potentially significant levels of the dispersants or dispersed oil. This report contains information about surface dispersant application, and provides additional context for the posted dataset. Characteristics of this dataset include the following: • This dataset combines results from aerial and vessel dispersant spraying activities during the DWH Response in a unified data file. • Before posting, extensive work was done to verify some aspects of the posted information (i.e., positional coordinates and field data). Surface dispersant application began on April 22, (field trial), and continued on days when the FOSC approved surface dispersant use until the well was capped on July 15, 2010. The last application of dispersant occurred on July 19, 2010. An additional application of 50 gallons of dispersant by boat on clean water was conducted on July 28, 2010 to obtain baseline fluorometry measurements, with a smaller volume used on one of the vessels at the source during recovery of the capping stack on September 4, 2010. The two dispersants used for surface application during the response, Corexit EC9527A and Corexit EC9500A, were listed on EPA’s National Contingency Plan Product Schedule (U.S. EPA 2010c) and preauthorized for use in the Gulf of Mexico.

Suggested Citation:

BP Gulf Science Data. 2016. Application of dispersants to surface oil slicks by aircraft and by boat in approved areas of the Gulf of Mexico from April 22, 2010 to final application on July 19, 2010. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N70G3HK6

Publications:

Paris, C. B., Berenshtein, I., Trillo, M. L., Faillettaz, R., Olascoaga, M. J., Aman, Z. M., … Joye, S. B. (2018). BP Gulf Science Data Reveals Ineffectual Subsea Dispersant Injection for the Macondo Blowout. Frontiers in Marine Science, 5. doi:10.3389/fmars.2018.00389

Purpose:

The purpose of this dataset is to provide documentation of dispersant application to the surface of water, including type and amount of dispersant, and location of application. These data were collected by BP to help guide cleanup operations under the direction of the U.S. Coast Guard and to support the Natural Resource Damage Assessment efforts by federal and state agencies and BP to evaluate potential injury to natural resources in the Gulf. The data and supplemental information are being made available to the public in a format that will facilitate the use of the data for research and other studies. GRIIDC is making these data available following the shutdown of the Gulf Science Data Portal. This will ensure that the data are available and searchable through GRIIDC data discovery.

Data Parameters and Units:

Data Publication Date = Date associated with the current data posting date (M/D/YYYY); Data Publication Reference = A general description of data provided in the data posting and a version control number; Study Reference No. = Study reference number (SRN) assigned by BP to provide a link between the data provided in the data file and the associated work plans and study descriptions; Association Identification = Association ID assigned by BP to provide a link between the data provided in the data file and the associated maps, shapefiles, work plans and study descriptions ; Application Date = Date of the surface dispersant application (M/D/YYYY); Application Identification = Identification of aircraft (using tail number) or vessel (using abbreviated vessel name) responsible for surface dispersant application; Quantity = Quantity of dispersant applied (in gallons); Dispersant Type = Identity of dispersant applied (Corexit EC9527A or EC9500A);

Individual Files: