After the ballots have been counted, it shall be the duty of the chairman or one of the judges to place them in an envelope and write thereon “Ballots of the City of Saint Paul, State of Alaska, of election held ______, 20__,” and send said envelope to the City Clerk, who shall keep said envelope containing said ballots for the period of at least six months, to be used by the canvass board only as needed. After use by the canvass board, the ballot package is sealed. At the end of six months, it shall be the duty of the City Clerk to burn said ballots in the presence of two City officers as witnesses thereto, and make and keep a memorandum in writing to these facts. One sample ballot may be maintained as a sample for the record. [Code 1979 § 5.21.]