A significant portion of the remaining oil from the 2010 Deepwater Horizon oil spill is sitting on the bottom of the Gulf of Mexico, within 40 kilometers of the well, a new study finds. The BP-operated Macondo well exploded in April 2010, and gushed an estimated 5 million barrels of oil into the ocean before engineers finally capped the well in July 2010. In 2014, researchers at Pennsylvania State University reported that coral communities up to 22 km from the spill site showed damage. Scientists estimate that about 2 million barrels of Deepwater Horizon oil ended up in the deep ocean. The researchers found an area of 3,237 square km, mostly southwest of the Macondo well, where a thin sheen of oil rests in patches on the top half-inch of the seafloor, according to the NSF.