If, for any one parcel, the municipality engaged in any removal activity on more than one occasion during the course of one year, then the municipality may combine any or all of the costs of each of those activities into a single notice of lien.
"Removal activity" means any activity for which a removal cost was incurred.
"Removal cost" means a removal cost as defined under Section 11-20-7, 11-20-8, 11-20-12, or 11-20-13.
"Underlying parcel" means a parcel of private property upon which a removal activity was performed.
"Year" means a 365-day period.
65 ILCS 5/11-20-15