Ariz. Rev. Stat. § 48-655
The treasurer and the county treasurer for the county in which the city or town is located may enter into an agreement for the county treasurer to collect the special assessments for the refunding bonds in the manner and by the officers provided by law for the collection and enforcement of general taxes. The treasurer and the county treasurer may provide by agreement for the payment of the county treasurer's collection expenses directly related to the levy of the special assessment and, if provided, the levy of the special assessment may include an amount for compensation of the county treasurer directly related to the collection of the special assessment. The compensation received by the county treasurer pursuant to the agreement is subject to section 11-496.
A.R.S. § 48-655