In addition to any other penalty imposed by this chapter for the erection, contrivance, creation, continuance or maintenance of a public nuisance, the cost of abating a public nuisance by the city shall be collected as a debt from the owner, occupant or person causing, permitting or maintaining the nuisance, and if notice to abate the nuisance has been given to the owner, such cost shall be assessed against the real estate as a special charge. (1975 Code Ch. 10 § I)