BfR-Wissenschaft 
47 
8 Meta-analysis on experiences from Deepwater Horizon 
Dierk-Steffen Wahrendorf 
Federal Institute of Hydrology (BfG), Koblenz, Germany 
The incident and the response measures 
The failure of a blowout preventer and other concomitant factors led to the explosion of the 
Deepwater Horizon drilling platform in April 2010. This incident in the Gulf of Mexico caused 
11 deaths and 380 to 780 million liters of crude oil were spilled into the marine environment. 
The incident caused the largest single marine oil spill in global history, cf. Figure 8.1. 
CoUllto 
de Bellver" 
© Tanker 
O Rig. pipeline, or well 
$3 War-related 
* Responsible pjrty unknown 
Figure 8.1 : Biggest oil spills in history (illustration by Nicholas Feltron, feltron.com). 
Beside the attempts to stop the oil flow as fast as possible several oil spill response 
measures were initiated at the incident site in order to reduce its impact on the marine envi 
ronment, Figure 8.2. Mechanical oil recovery was carried out at sea and on shore, in situ 
burning was conducted and oil booms and sand walls were used to keep oil away from the 
coastlines. To reduce the oil amount on the water surface approximately 7 million liters of 
dispersants were applied. For surface application 3700 m 3 of Corexit EC9500A and Corexit 
EC9527A were directly sprayed onto the oil slicks by vessels and aircrafts. And additional 
2900 m 3 of Corexit EC9500A were used for the subsea application. In particular the applica 
tion of dispersants is scientifically very interesting, as the dispersants were used in unprece 
dented quantities and also the subsea injection of dispersants directly at the wellhead was a 
novelty. Following the oil spill incident numerous research and monitoring programs were 
undertaken by industry and private companies, governmental agencies, public institutions, 
universities and NGOs. In order to determine the impact of the oil potentially affected organ 
isms and habitats were monitored.