(Added by Ordinance No. 175772, effective August 1, 2001.)  From 10:00 p.m. to 7:00 a.m., operation of commercial parking lot sweepers shall not exceed the sound levels for day hours set forth in 18.10.010.  After July 1, 2004, operation of commercial parking lot sweepers shall not exceed the sound levels for night hours set forth in 18.10.010 A and 18.10.010 B.