On November 3, 2011, the proposed Avenal Energy Project, a 600-megawatt natural gas-fired power plant proposed in the city of Avenal near Kettleman City in Kings County, California, encountered another legal challenge to providing electricity to the southern San Joaquin Valley. Sierra Club, Center for Biological Diversity, and Greenaction for Health and Environmental Justice challenged the Environmental Protection Agency’s issuance of a Prevention of Significant Deterioration (“PSD”) permit for the Avenal project via a Petition for Review filed with the Ninth Circuit Court of Appeals pursuant to section 307(b)(1) of the federal Clean Air Act (“CAA”). This is just the most recent turn of litigation activity involving the project. Avenal’s PSD permit has long been the subject of review and legal challenges. Among other claims raised to the Ninth Circuit, the Petitioners argue that the PSD permit impermissibly fails to address the recently adopted PSD requirements for greenhouse gas emissions.