Kirkland & Ellis earned $93 million for its work recovering environmental cleanup costs under an unusual fee arrangement approved by the U.S. Department of Justice, according to records obtained by The American Lawyer under the Freedom of Information Act. The amount included a $70 million contingency fee—possibly the largest such payment ever involving a federal agency.

Kirkland received the contingency award in January 2015. The remaining $23 million was paid in 2011 and 2012. Because the firm’s fiscal year ends Jan. 31, the $70 million payment was counted in its Am Law 100 financial results for 2014 and represented more than half of Kirkland’s reported revenue growth that year.