The U.S. alleges Hilcorp conducted well completion and flowback operations at at least 178 gas wells in the San Juan Basin (Rio Arriba County and San Juan County, NM) between 2017 and 2019 based on EPA information requests issued in October 2018, May 2020, and January 2023. As a result, the gas wells were subject to NSPS Subpart OOOOa. In particular, NSPS Subpart OOOOa required Hilcorp minimize its emissions during well completion and flowback operations (i.e., green completion). The U.S. alleges that Hilcorp failed to minimize these emissions, including GHGs and VOC, during the entirety of the flowback, and failed to meet recordkeeping and reporting requirements related to well completion and flowback operations, in violation of the NSPS. The CD will require Hilcorp to comply with well completion requirements of the CAA and NSPS Subpart OOOOa regulations on all well completions going forward. Hilcorp must hire an independent third-party verifier to conduct compliance verification for its well completions. As part of the injunctive relief, the CD will require that Hilcorp replace enough intermittent bleed and low bleed pneumatic controller devices at its San Juan Basin facilities on Tribal lands in NM with process controllers that are not natural gas-driven, to achieve emissions reductions that are more than excess emissions as calculated by the EPA. The CD will require that the mitigation project achieve emissions reductions of no fewer than 1,636 tons of methane (41,556 met