All dischargers subject to this Chapter must retain and preserve for no less than three years all records, books, documents, memoranda, reports, correspondence and summaries relating to monitoring, sampling and chemical analyses made by or on behalf of the discharger in connection with its discharge. This period of retention may be extended per 40 CFR 493.12(o)(2) when requested by the City Administrator, DEQ, or EPA during the course of any unresolved litigation regarding the discharger.  The discharger must retain and preserve all records that pertain to matters that are the subject of any enforcement or litigation activities brought by the City until all enforcement activities have concluded and all appeals deadlines have expired.