When the Director of Public Works finds that a user 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, the Director of Public Works may serve upon that user a written Notice of Violation. Within ten (10) days of the receipt of this notice, an explanation of the violation and a plan for the satisfactory correction and prevention thereof, to include specific required actions, shall be submitted by the user to the Director of Public Works. Submission of this plan in no way relieves the user of liability for any violations occurring before or after receipt of the Notice of Violation. Nothing in this section shall limit the authority of the Director of Public Works to take any action, including emergency actions or any other enforcement action, without first issuing a Notice of Violation.