Any Permittee which fails to have a qualified representative at the identified emergency need site within two hours after the City's representative informs the Permittee of the emergency need, as described in Subsection 902.06(a)(7), shall pay to the City a sum equal to Sixty Five Dollars ($65.00) for each one half hour, or portion thereof, by which the Permittee's qualified representative is late in arriving [i.e. arriving after the two-hour period described in Subsection 902.06(a)(7) has expired] at the identified emergency need site. A Permittee shall pay all late arrival charges within thirty (30) days after receipt of the City's invoice. A Permittee who fails to have a qualified representative on site within four hours after the City's representative informs the Permittee of the emergency need, as described in Subsection 902.06(a)(7), by such inaction authorizes the City to proceed with any excavation the City's personnel deems necessary, at the risk of the Permittee, and by such inaction the Permittee waives any and all right the Permittee may have had to recover from the City any damages which may result from the City's excavation.