All portable facilities and transient operations, such as portable rock crushers, but excluding portable hot-mix asphaltic concrete facilities, engaged in public work projects in any county except Dallas, El Paso, or Harris are exempt from the requirements of §111.111 and §111.113 of this title (relating to Requirements for Specified Sources and Alternate Opacity Limitations) and §§111.151, 111.153, and 111.155 of this title (relating to Allowable Emissions Limits; Emissions Limits for Steam Generators; and Ground Level Concentrations) if the conditions of §111.183 of this title (relating to Requirements for Exemption) are met.