"Sludge" means the material pumped out of septic tanks, grease traps, cesspools, seepage pits or other receptacles built and maintained to receive and collect sewage from buildings not connected to a sewer and in addition, includes treatment residues from water treatment plants and municipal waste water treatment plants. (Added by Amended Ord. 02-064, Dec. 9, 2002, Eff date Feb. 1, 2003).