In any county electing to follow the procedure authorized by this chapter, the board of supervisors, by resolution adopted in accordance with Section 4702, after holding a public hearing on the matter, may discontinue those procedures with respect to any tax levying agency or assessment levying agency in the county if the rate of secured tax delinquency in that agency in any year exceeds 3 percent of the total of all taxes and assessments levied on the secured rolls in that agency.