Section 550. County assessment of real property

1. If the alternative form
  of county government, or the modification or change of  any  such  form,
  shall  provide  for  the  transfer  to  the  county  of  the function of
  assessment of real property from the  towns,  villages  or  cities,  the
  director of finance, or county treasurer, as the case may be, shall have
  all  the powers and perform all the duties of the assessment officers of
  the unit of local government from which the functions of assessment have
  been transferred to the county. All provisions of law which apply to the
  assessment officers of such units of local  government  shall  apply  to
  such  officer,  except  that the board of supervisors may, by local law,
  enact such provisions relating to the assessment  of  property  in  such
  units  of local government as shall not be inconsistent with the general
  plan for the assessment of property contained in the tax law and subject
  to the general supervision and authority of the  state  tax  commission,
  but which may include, without limitation of the power thus conferred, a
  rearrangement  of  dates  for  the performance of acts, or the method of
  giving notices, or the place of filing  the  assessment-roll  so  as  to
  coordinate the assessment work; provided, however, that the county board
  of  assessment review of such county, if there be one, shall review such
  assessments in the manner provided in this article. It shall be the duty
  of the director of finance to adopt scientific  methods  of  assessment,
  including  tax and land value maps in the form approved by the state tax
  commission.
    2. If the function of assessment of real property is transferred  from
  the  towns  or  the  cities to the county, the school districts or parts
  thereof within such towns or cities shall use the county assessment.
    3. If the alternative form  of  county  government  provides  for  the
  transfer  to  the  county of the function of assessment of real property
  from any units of government within the county, such  form  may  provide
  for  a board of assessors, either three or five in number as provided in
  the petition or resolution by which the form or the question of adopting
  such board is initiated to be appointed by the board of supervisors upon
  recommendation of the county executive. At least one of  such  assessors
  shall  be  a resident of a city in the county if there be any such city,
  and at least one shall be a resident of the county outside of any  city.
  In  case  of  the  appointment  of a board of assessors, the director of
  finance shall have general supervisory power only over such  board,  and
  shall  not  have  charge  of  the  administration  of  the  function  of
  assessment of real  property  for  taxation,  which  function  shall  be
  performed solely by the board of assessors.