(a) Whenever the Agency determines that there is probable cause based upon an investigation that a violation of any provision of this Chapter or rule or regulation pursuant thereto has occurred, it may cause written notice to be served upon the alleged violator or violators. The notice shall specify the provisions of this Chapter or rule or regulation alleged to be violated, and the facts alleged to constitute a violation thereof, and may include an order specifying the necessary corrective action to be taken and specify a time for compliance which the Administrator determines is reasonable, taking into account the seriousness of the violation and any good faith efforts to comply with applicable requirements. Any order under this Section shall become final unless, no later than fifteen (15) days after the date the notice and order are served, the person or persons named therein request in writing a hearing before the Agency. Upon such a request, the Agency shall hold a hearing pursuant to § 49111 of this Chapter. In lieu of an order, the Agency may require that the alleged violator, or violators, appear before the Agency for a hearing at a time and place specified in the notice and answer the charges complained of, or the Agency may initiate action pursuant to § 49116 of this Chapter.

(b) No order issued under this Chapter shall prevent the Administrator from assessing any penalties, nor otherwise effect or limit the Administrator’s authority to enforce under other provisions of this Chapter or rule or regulation, nor affect any person’s obligation to comply with any Section of this Chapter or rule or regulation, or with a term or condition of any permit issued.

(c) Nothing in this Chapter shall prevent the Agency from making efforts to obtain voluntary compliance through warning, conference or any other appropriate means.