Worst-case discharge means the largest foreseeable discharge in adverse weather conditions, as defined at 33 U.S.C. 1321(24). The largest foreseeable discharge includes discharges resulting from fire or explosion. The worst-case discharge from a unit train consist is the greater of:
(1) 300,000 gallons of liquid petroleum oil; or
(2) 15 percent of the total lading of liquid petroleum oil transported within the largest unit train consist reasonably expected to transport liquid petroleum oil in a given response zone. The worst-case discharge calculated from tank cars exceeding 42,000 gallons is equal to the capacity of the cargo container.