Gulfport operates oil and natural gas production wells in eastern Ohio. The wells produce a mixture of natural gas, light crude oil (known as condensate), and naturally-occurring water (known as produced water). Several wells are typically co-located on a well pad, which is a collection of wells and production equipment, including storage vessels for containing condensate and produced water. VOC emissions from storage vessels can be significant and must be controlled by routing the vapors from the storage vessel headspace to a control device such as a flare or combuster.
In August 2015, EPA inspected a subset of Gulfport's well pads and observed systemic deficiencies in Gulfport's vapor capture and control systems, including continuously emitting tank thief hatches and pressure relief devices, and unlit flares and combustors.
In December 2016, EPA issued to Gulfport a Finding of Violation, alleging violations of NSPS Subpart OOOO (Crude Oil and Natural Gas Production, Transmission, and Distribution) because Gulfport failed to meet certain cover, closed vent system, and control device requirements; failed to design its closed vent systems to route all storage vessel emissions to a control device; failed to demonstrate initial compliance with Subpart OOOO requirements; and failed to operate its combustion control devices with a continuously burning pilot flame. In March 2019, EPA issued to Gulfport a NOV-FOV citing the permit provisions that corresponded to the Subpart OO