 The Harts' firm was registered to lobby on behalf of at least a half a dozen clients in industries regulated by the EPA, including Canadian energy company Enbridge.At the same time that Pruitt was renting the condo, the EPA approved Enbridge's plan to expand a pipeline carrying oil to the United States from Canadian tar sands.Enbridge had in 2010 been given the second-largest fine in EPA history for spilling crude oil into the Kalamazoo River in Michigan.