Clean Air Sustainability Act of 2007

Clean Air Sustainability Act of 2007 - Amends the Clean Air Act to revise the definition of a "major source" of hazardous air pollutants to specify that a source's "potential to emit" refers to its maximum capacity to emit a pollutant on the date the source is required to comply with a national emission standard, without regard to any lower subsequent emission levels of that pollutant attributable to compliance with such standard or other factors.