If any person causes, suffers, maintains or permits a public nuisance
to continue after written notice is given to such person by the City,
directing such person to abate the nuisance, and such continuation
goes beyond the time set for such abatement in the written notice,
then such person shall be liable to the City for the expenses incurred
in detecting, investigating and abating the violation, including attorney's
fees and the costs of monitoring compliance. The City may recover
such costs by civil action or by billing said person. The City may
also recover such costs by special assessment lien if the violation
relates to real property.