(a) Except as specified in subsections (b) or (c) of this section or §112.4 of this title (relating to Net Ground Level Concentration--Exemption Conditions), no person in the State of Texas may cause, suffer, allow, or permit emissions of sulfur dioxide (SO2) from a source or sources operated on a property or multiple sources operated on contiguous properties to exceed a net ground level concentration of 0.4 part per million by volume (ppmv) averaged over any 30-minute period.(b) No person in Galveston or Harris County may cause, suffer, allow, or permit emissions of SO2from a source or sources operated on a property or multiple sources operated on contiguous properties to exceed a net ground level concentration of 0.28 ppmv averaged over any 30-minute period.(c) No person in Jefferson or Orange County may cause, suffer, allow, or permit emissions of SO2from a source or sources operated on a property or multiple sources operated on contiguous properties to exceed a net ground level concentration of 0.32 ppmv averaged over any 30-minute period.