The D.C. Circuit upheld EPA's decision to reconsider greenhouse gas emission standards for model year 2022-2025 vehicles. States and environmental groups argued that EPA violated procedural and substantive requirements imposed by the CAA and that the decision was arbitrary and capricious. The Agency...

The Fifth Circuit upheld EPA's approval of Louisiana's SIP for controlling regional haze. Environmental groups challenged the approval of Louisiana's selection of low-sulfur coal over a more effective pollutant control as the best available retrofit technology to curb emissions at a coal-fired power...

A district court ordered an electric utility company to obtain a PSD permit to address CAA violations at its coal-fired power plant in Festus, Missouri. EPA argued that the company increased the risk of negative health impacts and premature deaths by releasing excess tons of sulfur dioxide from its ...

The D.C. Circuit vacated EPA's 2018 update to the Cross-State Air Pollution Rule (CSAPR). States and environmental groups argued that EPA violated the CAA by failing to require upwind states to reduce their contribution of ozone precursors to downwind states in accordance with the deadline by which ...

The D.C. Circuit granted in part and denied in part a petition challenging EPA's update to the Cross-State Air Pollution Rule. Environmental groups and Delaware argued that EPA violated the CAA by failing to require upwind states to eliminate their significant contributions in accordance with the de...

The D.C. Circuit upheld EPA's implementation of its Renewable Fuel Standards Program, which requires transportation fuel sold in the United States to contain a minimum volume of renewable fuels. Some industry groups argued that EPA arbitrarily refused to revise its 2010 point of obligation rule that...

The D.C. Circuit dismissed a petition to review EPA's order denying an environmental group's objection to renewal of a Title V operating permit for a power plant in Utah. The group objected that the renewal permit incorporated requirements in a 1997 Title I preconstruction permit that was based on a...

The D.C. Circuit dismissed in part and denied in part a petition to review EPA's 2016 revisions to its ambient air quality monitoring system regulations. An environmental group argued that the revisions violated the CAA by not requiring states to give advance notice and hold a public hearing when ma...

A district court granted in part summary judgment against EPA for failure to implement its 2016 Emission Guidelines and Compliance Times for Municipal Solid Waste Landfills. Eight states argued that the Agency failed to implement and enforce the guidelines by (1) failing to approve or disapprove exi...

The D.C. Circuit denied downwind states' petition challenging EPA's refusal to expand the Northeast Ozone Transport Region, which consists of states required by the Agency to enact tight restrictions on pollutants that contribute to ozone that drifts across state lines. The downwind states argued th...