The permittee shall warrant to the city the adequacy and continued satisfactory condition and function of all backfill and permanent patches installed by permittee or by any agent or employee of permittee for a period of one year after the permanent patch has been accepted by the public works director. Such warranty shall extend only to any unsatisfactory condition or function caused by inferior design, workmanship and materials furnished by permittee or by any agent or employee of permittee. (2003 Code § 8-06-10)