Except as provided in subsection (b) of this section, before the Department exercises its authority under § 4-109 or § 4-110 of this subtitle, the Department shall: Notify the delegated county or municipality of the violation and the Department’s intended action; and Provide reasonable opportunity for a joint inspection with a representative of the delegated county or municipality. If the Department determines that there is a substantial threat to the environment, the Department may take appropriate enforcement action without first providing a reasonable opportunity for a joint inspection under subsection (a)(2) of this section.