Regulators in New Mexico have slammed Targa Resources with a record $48 million fine, alleging the natural gas giant’s processing plant in the southeastern corner of the state emitted air pollutants at levels far exceeding permitted limits.

The New Mexico Environment Department said in a news release that it has issued a cease-and desist order mandating that Targa reduce emissions to permitted limits. It also alleges that Targa failed to meet reporting deadlines and made “an incomplete attempt” at providing a root cause analysis of the excess emissions.