It shall be unlawful, except as otherwise herein provided, for any person except a licensed plumber to carry on the business of plumbing insofar as it comprises the making of connections for any service connection, or the making of repairs, additions or alterations of any pipe, stop and waste, or any other device, connected with or designed to be connected with the city water supply system. Such licensed plumber shall be required to deposit with the city clerk such sum as the city council may from time to time designate as a guarantee of the proper performance of his work and to indemnify the city for any charges or penalties that may be imposed or accrue in connection with work done on his account. (Ord. 529, 11-2-1965)