(a) The Governor of the State of Texas submitted the 1990 base year emission inventories for the Houston/Galveston (HGA), Beaumont/Port Arthur (BPA), El Paso (ELP), and Dallas/Fort Worth (DFW) ozone nonattainment areas on November 17, 1992 as a revision to the State Implementation Plan (SIP). The 1990 base year emission inventory requirement of section 182(a)(1) of the Clean Air Act, as amended in 1990, has been satisfied for each of these areas.

(b) The inventories are for the ozone precursors which are volatile organic compounds, nitrogen oxides, and carbon monoxide. The inventories cover point, area, non-road mobile, on-road mobile, and biogenic sources.

(c) The HGA nonattainment area is classified as Severe-17 and includes Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty, Montgomery, and Waller Counties; the BPA nonattainment area is classified as Serious and includes Hardin, Jefferson, and Orange Counties; the ELP nonattainment area is classified as Serious and includes El Paso County; and the DFW nonattainment area is classified as Moderate and includes Collin, Dallas, Denton, and Tarrant Counties.

(d) The Texas Natural Resource Conservation Commission submitted State Implementation Plan revisions to the 1990 base year emission inventory for the Beaumont/Port Arthur area with a cover letter from the Governor of Texas dated August 9, 1996.

(e) The Texas Natural Resource Conservation Commission submitted a revision to the State Implementation Plan (SIP) on August 9, 1996. This revision was submitted for the purpose of satisfying the 15% Rate-of-Progress requirements of the Clean Air Act, which will aid in ensuring the attainment of the National Ambient Air Quality Standards for ozone. This submittal also contained revisions to the 1990 base year emissions inventories for the Dallas/Fort Worth, El Paso and Houston/Galveston areas.

(f) The Texas Natural Resource Conservation Commission submitted a revision to the State Implementation Plan (SIP) on May 19, 2000. This revision was submitted for the purpose of satisfying the 9 percent Rate-of-Progress requirements of the Clean Air Act, which will aid in ensuring the attainment of the National Ambient Air Quality Standards for ozone. This submission also contained revisions to the 1990 base year emissions inventory for the Houston/Galveston areas.