The owner or operator of a commercial or industrial establishment shall provide, at the owner's or operator's own expense, reasonable protection from accidental discharge of prohibited materials or other wastes into the municipal storm drain system or watercourses through the use of structural and nonstructural BMPs. Further, any person responsible for a property or premises, that is, or may be, the source of an illicit discharge, may be required to implement, at such person's expense, additional structural and nonstructural BMPs to prevent the further discharge of pollutants to the municipal separate storm sewer system. Compliance with all terms and conditions of a valid NPDES permit authorizing the discharge of stormwater associated with industrial activity, to the extent practicable, shall be deemed compliance with the provisions of this section. These BMPs shall be part of a stormwater pollution prevention plan (SWPP) as necessary for compliance with requirements of the NPDES permit. (2007 Code § 44-299)