Oil source fingerprinting interpretation results for samples collected between May 9, 2010 and June 10, 2013 from the Gulf of Mexico and adjoining coastlines

During the Response to the Deepwater Horizon (DWH) accident, the Unified Incident Command (IC) in Houma, comprised of agency and BP representatives, made the decision to collect samples for oil source interpretation under a number of sampling programs to aid in Response planning and decision making. Oil source interpretation involves using chemical, analytical, and statistical methodologies to assess the source of oil-related compounds present in a particular sample. In the case of the DWH accident, a key question was whether a particular sample contained compounds likely derived from Mississippi Canyon lease block 252 (MC-252) oil, as Response efforts focused on that type of oil. Generally, these samples were oil, tar balls, mousse, oiled vegetation, sheen, and sediment. Most sample collection and all of the analysis and interpretations were coordinated and conducted by BP consultants working with or within the Environmental Units of the Unified IC in Houma and, subsequently, the Gulf Coast Incident Management Team (GCIMT) in New Orleans, Louisiana. Interpretations were mapped daily and distributed by the Environmental Unit to the Unified IC; after the Macondo well in MC-252 was capped, the frequency of map generation was reduced until the last set of maps were distributed on June 16, 2011. This data posting provides the results of oil source interpretation efforts for samples collected between May 9, 2010 and June 10, 2013. This data posting includes this report, maps of sample locations and interpretations in portable document format (PDF), and sample information and interpretations in a Microsoft Excel file and an Environmental Systems Research Institute, Inc. (ESRI) shapefile for use with geographic information system mapping software. The dataset includes 1,480 interpretations for samples collected between May 9, 2010 and June 10, 2013. These samples were collected during 19 sampling programs, all of which are classified as Response (non-NRDA) studies; i.e., studies conducted by BP and/or government representatives under the direction of the Unified Area Command and in association with activities performed in response to the DWH accident.