Pen-ultimate Spew

The Deepwater Horizon oil spill (also referred to as the BP oil spill, the BP oil disaster, the Gulf of Mexico oil spill, and the Macondo blowout)

There seems to be no standardized term to describe this event, which occurred on 4/20/2010.
"Penultimate Spew" describes both the magnitude and messiness.

Oil from the pen-ultimate spew is still washing ashore after 4 years.