For the purpose of assuring safe and quality construction of building sewers, safe and quality connection of building sewers to the public sewers of the city and affording satisfactory protection to the sewer users of the city, no person, other than the owner of the property involved or a person working under direct supervision of the owner with the owner assuming all responsibility of that person’s actions, may construct, install, repair, reconstruct, excavate, or connect to the public sewers of the city, any building sewer, unless he is a side sewer contractor holding a valid license of the city. (Ord. 947-04 § 2).