Prior to the commencement of work, the permittee or the contractor for the permittee shall post with the city a maintenance bond for guarantee of such public works improvements with a surety qualified to do business in this state, a cash deposit, an assigned savings account or other security acceptable to the city in an amount equal to twenty percent of the estimated cost of the public works improvements for a period of two years after the completed job is accepted by the city. Release of bond or other security will occur two years from city acceptance if all maintenance has been accepted by the city. (Ord. 1496 §6, 2016; Ord. 875 §15 (part), 1990).