(a) A site in the Houston-Galveston-Brazoria ozone nonattainment area that has the potential to emit, as defined in §116.12 of this title (relating to Nonattainment and Prevention of Significant Deterioration Review Definitions), 10 tons per year or less of highly reactive volatile organic compounds from all affected facilities at the site is exempt from the requirements of this division.(b) A site in Brazoria, Chambers, Fort Bend, Galveston, Liberty, Montgomery, or Waller County is exempt from the requirements of this division except for §101.401(a) - (e) of this title (relating to Level of Activity Certification). The commission may revoke this exemption upon public notice of this revocation. If the exemption is revoked, the owner or operator of a site subject to this division located in Brazoria, Chambers, Fort Bend, Galveston, Liberty, Montgomery, or Waller County shall comply within 180 days of public notice.