Jurors awarded more than $1 billion in punitive damages on Thursday, after earlier awarding $495 million in compensatory damages.
The award in Baltimore County Circuit Court follows a $150 million award in 2009 involving about 90 households. The company is appealing that ruling.
Exxon Mobil Corp., based in Irving Texas, said the facts do not support the latest ruling and that it will appeal it as well.
The 2006 leak occurred in Jacksonville, a small, affluent community about 20 miles north of Baltimore. An underground pipe that burst beneath the gas station allowed more 26,000 gallons of gasoline to escape.
