In this action, we are addressing additional issues raised by petitioners following publication of the "Oil and Natural Gas Sector: New Source Performance Standards" (published August 16, 2012), but that were not addressed in the action, "Oil and Natural Gas Sector: Reconsideration of Certain Provisions of New Source Performance Standards" (published September 23, 2013). Specifically, this action will address reconsideration issues associated with the natural gas well completion requirements of the NSPS with which compliance is required by January 1, 2015. In addressing these issues, this action will propose minor revisions and clarification of the well completion requirements. The principal changes being considered include clarification of requirements for handling of flowback liquids and gases following hydraulic fracturing, clarification of the existing language regarding venting during some portions of well completions, potential addition of new definitions to further clarify the well completion provisions and potential revision of the definition of "low pressure well" based on information supplied by petitioners.