All dischargers subject to this chapter shall retain and preserve for no less than six years any records, books, documents, memoranda, reports, correspondence and any and all summaries thereof, relating to monitoring, sampling and chemical analyses made by or on behalf of a discharger in connection with its discharge. All records which pertain to matters which are the subject of an enforcement action or litigation shall be retained and preserved by the discharger until all enforcement activities have concluded and all periods of limitation with respect to any and all appeals have expired, but in no case less than six years. (Ord. 2003-74 § 1 (part), 2003).