Some refineries are lowering production simply to mitigate the credit costs. Others are beginning to export products to avoid the mandate. Both moves could tighten U.S. supplies and lead to higher prices at the pump. Most every refinery is hurt by this rule.

So an exemption from today’s mandate is far more than a perk—it is a lifeline, an outright payday. Making this indulgence even more curious is that it is being issued by the Obama EPA, an agency that isn’t exactly known for doing favors for beastly carbon producers.

So who is the lucky dog? Who could make this happen? That’s the best part. The EPA won’t say. The agency not only refused to name the refinery in its rule, but also obscured certain numbers in the document to hide the beneficiary’s identity. An EPA press officer would not give me the name, citing “confidentiality restrictions.”

The agency did send me a 2011 document that shows it granted exemptions at that time to 13 small refineries. But that exemption applied only to 2011 and 2012—and the 13 refineries had been recommended by a public Department of Energy analysis, which laid out reasons for the exemptions. The EPA rule this week said this exemption had been granted under EPA’s authority to evaluate refineries on a “case by case” basis. The press officer said DOE was involved in the evaluation.