In May 2008, Energy Capital Partners and a subsidiary of Martin Midstream Partners formed Cardinal Gas Storage, focusing on the development, construction, operation and management of natural gas storage facilities in North America. In August 2014, Energy Capital sold its interest in Cardinal to Martin Midstream.

Cardinal’s portfolio of salt cavern and depleted reservoir gas storage development projects included: Arcadia, an operating salt cavern natural gas storage facility in Bienville Parish, LA; Cadeville, an operating depleted reservoir facility in Ouachita Parish, LA; Perryville, an operating salt cavern facility in Franklin Parish, LA; Monroe, an operating depleted reservoir facility in Monroe County, MS.