All permittees subject to this chapter of this title shall retain and preserve, for not less than three years, any records, books, documents, memoranda, reports, correspondence and any and all summaries thereof relating to monitoring, sampling and chemical analysis made by or on behalf of a permittee in connection with its discharge. All records which pertain to matters which are the subject of administrative action or any other enforcement or litigation activities brought by the City shall be retained and preserved by the permittee until all enforcement activities have concluded and all periods of limitation with respect to any and all appeals have expired. (Ord. 2466 § 7, 1991).