EPA has two statutory regimes under which to regulate particulate matter and black carbon, national emissions standards for hazardous air pollutants (NESHAPs) and §111(d) existing source standards. NESHAP standards under §112(d) requires EPA establish the maximum available control technology (MACT) for hazardous pollutants, which are often correlated with the emission of black carbon. §111(d) standards for existing sources (such as Obama’s Clean Power Plan) would also reduce black carbon indirectly, by reducing fossil fuel generation in general.