The Director of Public Works may order a user which has violated, or continues to violate, any provision of this chapter, an industrial wastewater discharge permit or order issued hereunder, or any other pretreatment standard or requirement, to appear before the Director of Public Works and show cause why the proposed enforcement action should not be taken. Notice shall be served on the user specifying the time and place for the meeting, the proposed enforcement action, the reasons for such action, and a request that the user show cause why the proposed enforcement action should not be taken. The notice of the meeting shall be served personally or by registered or certified mail (return receipt requested) at least ten (10) days prior to the hearing. Such notice may be served on any authorized representative of the user. A show cause hearing shall not be a bar against, or prerequisite for, taking any other action against the user.