Bloomberg reports that Chevron Corp. sought permission from Richmond, California, regulators yet again to upgrade equipment at its refinery there. A California court halted construction on new equipment at the Richmond refinery in 2009 amid concerns the upgrades would allow it to refine heavier and more polluting crude oil. The company said its new permit application will address questions raised by a California appellate court last year about an environmental impact report prepared for the project. The appeals court found that the environmental report failed to specify whether the upgrades would allow Chevron to refine heavier oil and to outline measures for mitigating increases in greenhouse gas emissions. The Richmond City Council had relied on the report when it voted 5-4 in 2008 to issue permits for the project.